Rim brake rims in the 450g to 500g range have a 1.4mm thick brake track approximatley. There are slme heavier rim with thicker tracks.
Aluminium is only so hard. Yes some brands of rims like hed have used a hard alloy. Borg rims are not as hard as those but mid pack ( or better). Similar in fact to higher end DT Swiss rims. Some cheaper rims use softer metal.
The material hardness will have an inpact on rim life but its not big.
Much more important is
Terrain is the obvious thing. Those hilly narrow lanes covered in muck will kill any rim. Where as flat fen land roads where you rarely brake help rims last.
Urban riders can suffer from.brake wear if they stop start alot but in general urban riders tend to have cleaner roads.
Sadly the country roads are spending more and more time covered in muck and the weather is getting wetter and wetter. Add the poor state of most roads is leaving more debris to be picked up by brake pads.
That leads to the pads. Softer pads like aztec and Koolstop salmons so help rims last a bit longer but they are not magic bullets.
How you brake is also a factor. DraggIng the brake is going to wear rims nicely. Whereas firm burst braking can help dislodge stuff stuck in the pads and therefore rim life is extended.
Now the rim should be replaced at 1mm thick. It safe there but let it wear down to 0.7mm thick and your in the danger zone. This is easily measured but if it very concave get concerned.
Now how many miles this takes can be as little as 2000 miles or as many as 20000 miles for alloy rims.
Carbon rims can last alot longer. 30000km is not unusal from carbon rims. They can last longer than that.
All our wheels can be re rimmed though. Spokes can often be resused. So it a labour charge and a new rim and nipples. If hub bearings need attention then we can do that as well.
]]>Pillar manufacturer excelent spokes from the same wire stock that Sapim use - Scandvik T302 18/8 stainless steel.
We will be importing triple butted spokes. These offer a better fit in almost all hub which commonly use a 2.5mm dimater spoke hole. Also a thicker elbow -2.2mm - means longer fatigue life for the spoke.
PSR TB2016, PSR TB2017 and PSR TB2018 spokes are on order in silver and black. J bend only.
These spoke have a 1.6mm, 1.7mm or 1.8mm centre section. 2.2mm spoke elbow and 2.0mm after the elbow.
The other spoke we are bring in is the Wing 20 and Wing 21 in J bend and straight pull and silver and black.
All spokes will be bought as blanks and cut and thread to order in the shop. Pillar use a 30mm barrel so each blank has a 10mm spoke range it can be cut too.
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So the first that will arrive are the new disc brake hubs.
These share the same bearings and freehub as the 2:1 hubset.
Flange size is large at 59mm which reduces the spoke tension changes when compared to a small flange design. The hubs flange spacing is kept as wide as possible to maximise spoke bracing angles.
The bearing used are from NTN. NTN are one of the world's top tier bearing companies and these bearing are used solely in our hubs. The Cycle Clinic is also an NTN bearing distributor. The bearing used in the hub shell are 6902 to ensure decent life.
The freehub uses 4 independently sprung pawls running in a 36T ratchet ring.
This same bearing arrangement for the rear hub and the freehub is used in the new rim brake hub. The front hub you already know. It the same as used in the 2:1 hubset.
Rear flange spacing is 16/39mm to ensure stiff rear wheels. Finish will be black and silver. The same bearings offered in the 2:1 hubset and the freehub is the same as the 2:1 and disc brake hub.
]]>So let pick this apart by starting with the basics. A wheel is nothing without a tyre and a tyre is useless without a wheel. A wheel should be designed to get the most out the tyres they are intended for. That means standards and sticking to them. ETRTO set these standards and they are not just about safety.
Whats the perfect tyre shape? Well circular just like a tubular. Thats why tubs handle so well.
Clinchers or tubeless clinchers will deviate from that perfect shape. How much will determine how much the handling is affected. If the rim is to narrow and tyre too wide the tyre can light bulb and give vauge handling in the bends.
If the rim is too wide for the tyre the tyre ends up shorter and wider but the crown is flatter and the sidewalls straighter. In the case of knot64 wheels, the tyres Cannondale supply are stretched so much the sidewall curves inward from the bead.
A tyre thats stretched will not handle as well as if it wear mounted to a rim of the ideal width. That is the
Now such combinations of a over wide rim and narrower than ideal tyre is often paired to lower aerodynamic drag. This however one aspect of the wheel, tyre system.
The move to wider tyres does make some sense. On perfect road surfaces they should show higher rolling resistance but roads are not perfect are they.
Wider rims mean less sidewall flex which in turn lowers rolling resistance and less sidewall flex can improve tyre handling. There are limits though. Sidewall flex also impacts tyre feel. Reducing flex too much can make tyre tyre feel snappy. Tyre flex is your road feel. Stiffer sidewalls still flex but the snap back harder. The result is sudden loss of grip at the limit with little warning. Just like on some cars which give no feedback to the driver. Too much sidewall flex is a problem also. If the the tyre becomes too stretched rolling resistance can increase. Remember the shape of tubular tyre.
When the crown of the tyre is flattened off by mounting on a rim that too wide, the tyre wears in unfamilar ways. When cornering the tyre still ends up wearing the centre more than it would if the tyre is mounted to a narrower rim. In testing various rims i have had 25mm IRC Formula pro tyres and Continental GP5000 tyres mounted to 20mm internal with Velocity aileron rims and wider rims. The wider the rim the more noticable the excess wear in the centre section of the tyre is. 28mm tyres did not show this problem on 20mm internal width rims. Therefore to keep my road wheels compatible with 25mm tyres the internal width are no wider than 19mm. Essentially a narrow tyre on a too wide rim will square off sooner and have a shorter life.
Rims that are too wide also expose the side walls of the tyre and the rim itself to damage more frequently. There is nowt slower than the tyre with a damaged sidewall or a wrecked rim. Pinch flats on stretched tyres are more likely.
In order for a tyre to be made for a rim that really wide it shape has to be altered. Because a bicycle tyre has no shape without air pressure (this keeps tyre weight down) we will not see tyres shaped like you do on cars or motorcycles any time soon. You can alter tyre thread thickness at various points on a tyre though to optimise the crown shape for ultra wide rims. However such tyres then are not optimised for narrower rims and so far there are no road tyres made that way.
Tyre manufacturers mostly make tyres (unless they state) that meet ETRTO specifications. While the tyre size chart can be a stretched a bit without consequence for example a 25mm tyre on a 19mm internal width rim many of the the current wheels offered by many manufacturers are more than pushing the envelope. Even for those that make tyres and wheels thoe tyres will be made to ETRTO specifications.
This is why our road wheels are 19mm internal width not 21mm or wider because wider maybe more aero but thats too focused. 19mm is wide enough for 25mm tyre to 40mm while preserving the tyre shape the tyre manufacturer intends. A good wheel has to balance characteristics.
Our gravel wheels there for start at 23mm internal width to stop road tyres being used on them (I hope). Gravel wheels use rim widt that are used for MTB's.
I hope you can see tyre shape is key to how a tyre preforms and wears. Since the tyre is what keeps you upright get the most out them. Pick the right rim.
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The rotor and any adapter must be removed. Use a 1.5mm allen key to undo the grub screw on the left side of the hub and undo the adjuster.
Fit the wheels and secure them normally to the frame or fork. Advance the adjuster till there is just no side to side play. Secure the grub screw.
Remove the wheel and refit the rotor and the wheels can be refitted.
To inspect the bearings or remove the freehub use a 12mm hex key on the left side and a 17mm spanner and undo the left end cap. At this point you can replace the axle, freehub or carry out any other maintenence job.
The front hub has no preload adjustment. The end caps are push fit. There are two bearings in a shell. Therefore to inspect the bearings just remove the end caps.
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1) to replace bearing
2) to replace freehub body
3) to add grease to freehub mechanism.
Bearing require changing when they are not longer smooth. When the bearings spin with noise they are worn. They will spin freely at this point but there will extra drag with rider load on the wheel. Bearing life should be long.
Insert 2x 5mm allen keys into end caps. Normal right hand thread and undo. One end cap will undo.
Insert a 10mm allen key into the axle and with the other 5mm allen key remove the other end cap.
The freehub bearings should be removed with a blind or collet style puller and refitted.
Freehub pawls and springs are a spare part and can be replaced.
To remove axle knock it out with a rubber mallet from the drive side. The nds bearing will push out of the shell.
Use a bearing puller to remove drive side shell bearing and a bearing press to fit new NTN 6902 bearings.
The freehub bearings are NTN 6802.
Pictured here are shell bearing with contacting seals and a freehub with non contacting seals.
The hubs are made with the tight tollerances that NTN bearings provide. Therefore use of other brands of bearings while possible may affect bearing life and hub performance.
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ETRTO is a standard organisation that lays down specification for tyres and rims. Standards for bead hook design are mandated and for tyres. My rims conform and all the major tyre manufacturers conform to these standards too.
Wider rims are often hookless as well. Hooked rims are recommended for all road and gravel width tyres. Often the rims used for road and gravel are the same and non of the major tyre manufacturers say its fine to use there road tyres with hookless rims. Some say explicitly you should not. Hookless rim are really an mtb creation for tyres inflated to 30 psi or under. While some claim pressures are fine much higher for road tyres remember to hookless carbon rim (its mostly carbon) exists solely because some rim manufacturers find it too expensive to make there bead hooks properly. Some never made them properly in the first place (ENVE bead hooks don't conform to ETRTO standards). I don't offer hookless rims. If your using one no IRC road tyre should be used with them. The gravel tyres I sell should be fine used tubeless and with pressures under 40 psi.
There are many rim and wheel manufacturers now touting 23mm, 24mm and 25mm internal width rims and some say tyres from 25mm wide are fine. They do this because wider is better innit and it more aero.
The problem is tyre manufacturers say different. At the extremes when say mounting narrower 25mm or 28mm tyre to a 23mm internal width rim one risk is tyre blow off. This is risk is higher with hookless rims than hooked rims. However this is the extreme for example the 28mm tyre pictured below mounted to 23mm internal width rim/28mm external width. This may not actually blow off but it shows another problem. Tyre shape.
Tyre manufacturers like IRC want there tyres to have a shape range. The top of the tyre should form a circular arc so when riding your on the centre of the tread and when corning you move progressively over the shoulders the more you lean into the bend.
With a stretched tyre the shape is flattened at the top and this does affect how the tyre handles. You maybe more aero but slower in the bends. This especially true off road with off camber and undulating terrain.
The side walls are also more exposed with stretched tyres to damage. Gravel and potholes on the road or all those roots, stones and holes off road are more likely to slice a side wall. Nothing slower that a blowout tyre. Tubeless tyre pinch flats are also more likely with over stretched tyres.
This is why i am not following the wider is better trend. It works to a point.
Suggested tyres rims for rim sections. These stretch the older ETRTO guidance a but new guidance was issued in 2020 which confirms my chart. You can actually go wider than i suggest safely but higher pressures would be needed to avoid tyre squirm in bends. This also affects tyre performance so the max width seem to be practical maximiums. The minimum width really are minimums and with some tyres there may be pinch flat issues. With the wider rims the min tyre width is barely recommended as these are off road tyres and pinch flats are more likely at the bottom end of the tyre range.
Rim internal width mm tyre width mm
15mm 23mm to 32mm
17mm 23mm to 36mm
19mm 25mm to 42mm
20mm 28mm to 45mm
21mm 32mm to 50mm
23mm 36mm to 60mm
25mm 40mm to 65mm
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First riders are not strong enough to cause notching. Regardless of how strong you think you are you can't notch a freehub that has a properly installed lockring.
The pic is of one of my freehub. Notching should not get any worse than this. Its barely notched.
First notching can only occur if the cassette lockring does not provide enough preload to the cassette. Thay preload stops the sprocket slipping and notching the freehub.
Grease freehub splines lubricates them. Dont do it. It is likely to make notching more of a problem.
Recommended lockring torque is 40 to 50 Nm.
Not all torque wrenches tell the truth. A good mechanic has feel. The tool and feel tell you if your getting tight enough.
Due to manufacturing tollerances there an be a range of preload applied to the cassette hence feel is important. So the correct torque can be aplllied but the correct preload not. Don't be a torque wrench slave. Lubricating lockring threads does reduce the variation in preload applied but also increases it and could result in stripped threads. There we fit lockrings without greasing them. We ensure the threads are sharp and clean.This way the correct preload is applied to cassette when the lockring is at 40 Nm.
Most lockring tigheneing effort is used to over come friction so dirty or damaged threads mean notching is more likely.
If you get a freehub that notches, file the burrs and thick about what could have caused it. Its not the freehubs fault you just need to be a better mechanic.
One of my alloy freehubs is pictured after a few thousand km. No notching because i avoid the errors above.
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Formula Pro Light TL, Formula Pro RBCC TL, Formula Pro X Guard TL tyres have recieved a overhaul for 2020. Initially available in 25mm and 28mm 700csizes with 30mm width being avilable later in the year.
IRC's proprietary technology that blends RB ceramic particles, a hard porous carbon material made from rice bran, into the tread rubber. The RB ceramic particles, which are extremely small (200-300㎛) and are hard, exert a micro-spike effect, and at the same time, have a high gripping power even on wet roads due to the porosity with an excellent water absorption effect. With this update, the rolling resistance is maintained, while the grip, abrasion resistance, and weather resistance are greatly improved. It has evolved into a compound that maintains a high grip on all road conditions, both dry and wet.
Due to the hard porous structure, it exerts a micro-level spike effect on the tread surface. Due to the abrasion of the tread rubber, new RBC particles appear on the face, and the traces that have fallen off also function as minute edges. In addition to the water absorption effect due to the porous body, the small holes that have fallen off temporarily hold water on the road surface like a foam rubber and cut the water film. Useful for improving grip on wet roads.
So the Formula Pro tyres will retain there reputation for unparalleled grip even on wet greasy winter roads.
IRC Formula pro tyres are cobbletastic. The tread extends to the sidewalls improving puncture and cut resistance. Perfect for rough roads.
The Formula Pro X Guard TL tyre gets the 40x40 TPI beadto bead puncture protection belt. This improves puncture protection by 40% over the RBCC tyre model. The X Guard belt is the difference between the two tyres. The X Guard belt being less flexible increases rolling resistance a bit and decreases comfort and grip a bit.
Technology that reduces rolling resistance of tubeless tires. The NR-TEX IAS, the tire's air retention layer = inner air seal is composed of a supple and highly repulsive natural rubber base (NR) compound to pursue faster and more supple performance. You'll like the comfort of these tyres.
180TPI casing. Well that says it all. Comfy.
Pinch flats are possible with tubeless tyres. Without bead protection a bead puncture can happen. While these can be plugged the repair is temporary. The old IRC Formula Pro RBCC tyre victim of these. The Formula Pro X Guard was not due to the bead to bead protection. So the new Formula Pro series get bead protection so all the tyres are now potholetastic or cobbletastic.
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Carbon spokes do offer advantages. They are light and dont fatigue like a steel spoke does. If a fatigue test was done they would last 10 times longer. Part of the issue in the past has been fixing the spoke to the hub. This new spoke has alumium ends and substainal ones at each end. One end is the thread and the other is a straight pull head. The wheel is then assembled and tensioned with internal nipples whilst holding the thread end with a spoke key to stop twist. This mean the spoke is not at risk of damage when building. So this is a wheel that repairable. A damaged spoke can be replaced easily.
These spokes are 1.2mm wide and 3.2mm thick. They are very stiff. They dont bend much at all. This means they should not be interlaced.
37 spokes weigh 106g with nipples.
The rim is 26mm wide, 19mm internal width and 50mm deep. Its 443g too. Its filament wound with a thicker spike niplle bed but thinner in between.
The hubs are quite well made. They use 6803 and 6903 bearings. They are 3mpg for the pair and can only be used with these carbon spokes. I would however prefer my own hub based on the BORG2:1 hub as bearings will last alot longer and I get to use the hubs internals on a carbon spoke compatible hub. This means I will better able to ensure spare supply.
Wheelset wight is just over 1300g.
The wheels built up easily. And took high loads when I stress test it. Any wheel that can take 600N of side load without going out of true even by a little bit is going to last
IRC formula pro light tyres have been fitted with Maxalmi tubeless sealant. The wheels are in my Camapagnolo ex promotion bike. the first pedal stroke was a revelation. Spokes that dont change length when the wheel is loaded make that wheel feel responsive. These are responsive. The braking is excellent too and a step up on previous rims I have used or still use.
More testing needed and more test wheels will be built. Plus I have money to spend on a new hub.
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Those more at ease with the physics of this will notice what I am presenting here is a basic model but it illustrates what going on.
One common misunderstanding is that aero gain are only important at higher speeds. Not true. Power required to overcome air resistance is directly proportional to the drag coefficient. Often people relate power to the riders velocity but since this the variable here the constant of proportionality is the drag coefficient multiplied by frontal area, CdA for short.
So a 5% reduction in CdA results in a 5% reduction in power used at any speed. Since a slower cyclist spends more time on a course that leads to the slower cyclist saving more time in tt with aero wheels that say Alex Dowset would if one could persuade him to the Lavenham 10 on Mavic Askiums compared to the BORG50C for example. That's not the same things as saying aero wheels benefit slower riders more than faster riders as that's not true. If the same time difference were expressed in terms of a % then the faster riders see more of a % percentage benefit than the slower rider.
So air resistance can be
Power to overcome air resistance P(ar) = 0.5 × CdA x rho x v^3
Wheels change the CdA of the rider and bike and through that affect the riders velocity.
Rho is air density which is 1.2 kgm^-3
for your average cyclist moving at 18 mph on mavic askiums then a set of BORG50C wheels will add 0.5 to 1kph to your speed roughly. This may or may not be significant to you. If it isnt and for most people it isnt then your buying based on looks. Nothing wrong with that.
I am going to refrain from predicting time saved for particular course as such calculations are not meaningful.
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Bike fitting is pretty straightforward. All bike fitting start it must start with the saddle
Step 1 now level that saddle off with a spirit level. Some saddle have a shape where a spirit level is useless you can either change your saddle here or use your eye. Tilted down a couple of degrees wont hurt (old shimano seatpost only allowed your seat to be nose down slightly) but you might slide forward a bit. Nose tilted up is never desirable.
Step 2.
Now set your saddle height. This is measured from centre of bb axle to the top of the saddle. Once this is determined this is fixed height for all your bikes. The saddle height is the single most important thing to get right which is why it has to be done first. The lemond method takes your inseam measurement (taken with a book jammed into your crochet and a tape then dropped to the floor) and multiply it by 0.883. This is your saddle height but it only a start. It may have to go up or down a bit. The weakness here is crank length. It takes no account of crank length with 20+ bikes with cranks from 165mm to 177.5mm my saddle height has to vary a bit by a couple of mm from bike to bike. For me its 795mm. Correct saddle sort many knee issues out.
If your hips rock alot or you have dip your foot at the bottom of the pedal stroke then your probably got your saddle too high. Let your legs dangle when on the saddle. The angle your lower leg make to your upper is not far off the how your leg should look at the bottom of the pedal stroke. You can do this bio mechanically without measuring anything. I know the how your leg should look by eye. You may not but you can set your saddle height by raising it till your hips start to rock when pedalling. If there is more than 2cm of movement left hip to right hip then your saddle is too high. That's not an exact measurement but your hips should not be rocking. Your foot is another tell tale sign. When pedalling the tow of your foot should be pointing up a bit, like your scraping shit of your shoe. Whe your saddle gets too high you toe no longer does this so stop raising your saddle. Between these three observations the saddle can be set. Once it is set correctly, measure it.
http://veloptimum.net/Velop/documents/1-choisir/RBR15juil10.htm
Step three. Sit on the bike and pedal. Do this for a minute of two until your settled. Note how far back your bum is. Your bum should be at the back of the saddle. Adjust saddle for and aft till your bum is at the back of the saddle when pedalling normally.
Now that's the saddle set. Dont alter it. This is fixed unless your leg length changes. Most saddle comfort issues are addressed by proper positioning. Saddle choice is often affected by position and clothes worn. Harder saddles work well for long rides with padded shorts. Soft saddles are fine in civies and shorter journies. The more upright your position the wider the saddle can be. The flatter you are the narrower the saddle needs to be. If proper position does not help you your saddle has to be changed.
Now to the front of the bike. When one is sitting on a bike you should really feel like your in it. This means something specific in terms of position. Your back should be straight
Not ruler straight as backs are not like that but you should not be hunched or have an excessive curve in the upper half of your back. You should feel relaxed. Your arms should be slightly cocked on the tops, hoods and drops. Your arms should also be perpendicular to your torso. If that arm to torso angle is greater than 90 dgress your probably over stretched and the shape of your back will show it. Your shoulders should not be pushing back out of your back. This leads to bunching. You end up cranking your neck then. Essentially imagine your standing then bend over,that how your back should look. Your neck then sorts its self out. To achieve this position you have stem length, rise and bar reach/drop to sort alter.
You can take any position from upright to flat and makes an arc because you arms in all cases are only slightly cocked I.e a relaxed out position. Even if you think your not flexible you dont have to have the bars higher than the saddle. That's for upright positions. Upright right positions are not more comfortable. They are used or should be for improved visibility. This is important in urban areas. Hense riding tt bikes in cities is not always wise. That old trek bike below is mine. I cant get within 15cm of my toes when trying to touch them yet I consider that position on the dirty old trek to be conservative. Lacquer is peeling but it works hand that all that matters really. It's also offers a comfortable position for 200+ mile rides. Again its comfortable well as a comfortable as a alumium bike is with 22mm tyres that is. With proper position you can adopt a range of positions on the arc your body shape allows. You can of course ride in a more upright position it's perfectly fine if it's on the arc of acceptability.
So step 4.
Adjust your bars so the drop ends are parallel to the ground. Tilted up a bit is acceptable. Exactly how they sit will depend on your shifter brake levers. shifter/brake lever position should lever a flat area for you hands with modern unit. The bar tops to the levers are essentially flat. When levers are pointing up to bring them closer that a sign that the bar reach or stem length is too long. This also has the effect of putting stress on the wrists as they are no longer in line with your forearms. Perhaps the steerer has been a cut too short, in other words parts should be changed. Old bikes with old brake levers dont give you this luxary. Your meant to sit in the drops and brake from the drops.
Select your bars so you can sit with your hands on the tops,hoods and drops and operate all the controls without you shoulders pushing back, arms straight but slightly cocked and you should feel relaxed. If your too flat you'll feel it. I get pain around my hip and crotch if I am too flat.
Stem length is picked to complement the bars. Stem angle is the last main thing. Stems come in different angles. Commonly road bikes have a negative angle stem so with commonly used head tube angles. They can be either way up and flipped they raise the bars but shorten the stem. 82 to 84 degrees angle is common. 0 degree stems are neutral. They are the same flipped. Stem with rise will pull the bars in as they lift them. So be careful your not creating undue bends in your arms. The higher the rise the shorter the stem is effectively.
You can also lift the stem up which was easier on old quill stems. Given the head tube angle lifting the stem up means pulling the bars back so stem length may have to alter.
Most of the problems start with position when the rider feels uncomfortable and starts altering the front end in a haphazard way often making matters worse.
That's the basics it can be done at home. The approach has to be methodical.
Of course it helps to be on a frame that is sized so you can make it fit.
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I'll start with IRC because I distrubute these. I am biased. I love these tyres.
IRC have 4 road tyres, 6 CX tyres and several MTB tyres. IRC tyres are not the lowest rolling resistance tyres out there. I dont care about that because they are hard wearing and grippy, oh so grippy in the wet.
IRC Roadlite tubeless- this is IRC fastest road tyre. It is also the least grippy of the 4. That's a relative term as it's still grippy. Cut resistant and good training tyre that you can race on. On Borg rims the 25mm tyre is 27.5km wide and 24mm tall. They hold air well being a butler lined tyre.oh they are comfortable too. I did PBP on these.
IRC Formula Pro X Guard - my favourite road tubeless tyre full stop. Its grippy in ways other tyres want to be and it hard wearing too. The puncture protection belt keep the P fairy at bay most of the time. 6000km from the rear tyre on my pannier laden commutor is normal. No other tyre last me as long. On borg rims these tyres size at the size they should be. Comfort is quite good on these tyres. Enough for 200 mile rides. It's a lined tyre as well so holds air pretty well.
IRC Formula Pro RBCC - the wet grip on these is insane. Plush dugast tubulars or Vittoria Pave tubulars are as grippy.this is high praise. Grip is this tyres party trick. As durable as the X-Guard but not as puncture resistant. Comfort on these is fine and I done many 200+mile rides on these tyres. It's a lined tyre as well so holds air pretty well.
IRC Formula Pro Light - well it lighter than the other tyres in the range. It's meant to have lower rolling resistance but it's not a tyre that meets my needs. It has thinner sidewalls but this tyre is still more hard wearing and its sidewalls are thicker than many others. It's a lined tyre as well so holds air pretty well.
IRC Serac tyres. They come in Sand, CX or Mud version. There are X-Guard versions of all three 32mm only. These are CX tyres really and I don't do CX (horrible sport, tried it once and it was hard) but the sand tyre is a good narrow gravel tyre.
IRC Boken and Boken + I dont own a gravel bike. Gravel to me is old fashioned XC riding so I do that instead. However I know many gravel riders that love these tyres for there grip. There are lighter and faster gravel tyres but for grip well this is your tyre. Grip = fun and it keeps you upright.
IRC Mythos, Serac XC and Stingo since enduro and down hill scare me I have not tried IRC tyres for these disciplines but I do use there XC tyres. Like the other tyres there are lower rolling resistance tyres but once again IRC's party trick is longevity and grip. The mythos is my summer dry tyre and the Serac XC and Stingo are my winter tyres unless I am using Conti tyres.
Continental well they make the Competition tubular which is the best tyre in there range. The grip is insane. I love these tyres however Continental make some really good tubeless tyres now.
GP5000TL - I call this a TT tyre because its quick. In fact its possibly the fastest relaible tyre out there. During my winter test on my commutor the rear lasted 2500km before it wore out. Longevity is not there thing. Grip is pretty good and they have a damped feeling. You want these because they are quick and reasonably reliable. That's it. Some people think they are tight so use an IRC tubeless tyre lever. You wont break one of these and these lever help you lever these tyres on. I have no trou le fitting them but then again I have no trouble fitting Conti tubs either.
Race King and Cross King - I really like these tyres. Faster than the IRC's but conti tyres are thinner so punctures are more likely. Still for a fast decently grippy tyre there is nothing else I go for.
Conti gravel tyres- no idea I still think gravel and XC are same thing.
Hutchinson- back in 2006 the French and Shimano teamed up and established a tubeless standard so you think Huthinson would know what they are doing and they do. Hutchinson make tyres for Pirelli, Zipp and Mavic.
Hutchinson Fusion 5 Performance- pretty quick and reasonably puncture resistant tyre. They wear out ( rear after 3000km) fairly quickly but they are one of the cheap road tubeless tyres so this can be forgiven. Grip is pretty good as well.the fit is pretty easy.
Hutchinson Fusion 5 Endurance - pretty quick for a winter tyre and decently reliable. I am still wearing my set out but it look like after 1500km they are half to a third there way through there life. Comfort is there down fall but that a relative term. They are way better than a Conti Gatorskin in any size. The fit is pretty easy.
Mavic Yskion Pro UST.the compound is the same as the Hutchinson tyre but the for is meant to be better. They however are just as easy to fit as the Hutchinson tyres. They hold air well, offer good wet grip and are fairly quick tyres. Puncture resistance is fair and they wore out (rear) after 3300km.I like them and would use again.
Goodyear Eagle - tubeless tyres should really comfortable and most are. This is the only tyre that transmitted road buzz and a noticeable ammount. The bike buzzed. Grip was o.k and they reliable enough but after 800km they delaminated and the importer blamed it on my sealant choice. Its not the sealant. Oddly enough they are not for sale here. Unless the importer backs up retailers I cant be bothered selling them.sowhy sell a buzzy tyre.
Schwalbe - i have tried to like this brand but i cant stand any of there tyres. They hold air fairly well for a tubeless ready tyre and there fit is secure. Schwalbe do understand the ERTRO standards.
One tubeless - this older model punctured quite a bit but grip is its main problem. In the wet they scared me. Cornering on these in the wet is something best done slowly. They are quick though in a staright line, in the dry.
Pro One - I once tried selling these and customer after customer told me how shit they were and they are going back to tubes. I tried them and they are shit. Oddly enough I dont sell them now. The wet grip is O.K but nothing special. They are quick enough while they are holding air. The slowest tyre is one that puctures. One ride home(15 miles) i got 6 punctures on an unworn tyre. Nothing is slower than a flat.
Yes that's 6 flats in 15 miles, thats 6 plugs and I am sure there were more holes. They leaked from places I couldn't even see. If your light and lucky you might get away with using them but the conti GP5000TL is a better fast tyre.
Schwalbe Rocket Ron and Racing Ralph. I cant understand what the fuss is about. Yes they are really quick but I go wide in the bends with them. Give me a Conti or IRC XC tyre anyday.
Schwalbe Marathon supreme - I don't have a road bike that can take them. Given Schwalbe's compound choice I am not likely to like them.
Vittoria Corsa Control G2.0TLR - grippy and comfortable but best used with inner tubes
Oh wait they do a tubed version which is cheaper so buy that instead. So what wrong, well they are tubeless ready and while that not a problem normally in this case it is. My pair were porous. Sealant never fixed this. The sealant dried out after a week or two meaning punctures never sealed. They punctured. After 3300km I got fed up and binned them. I'd use them again in tubular form though. In er tubes for me belong in sew up tyres only.
Vittoria Rubino Pro G2.0 TLR - I am only about 1000km into testing these and so far they are great. There are more comfortable tyres but in 28m. Form they are comfortable enough. There are tyres with better wet grip but these are grippy enough. There are faster tyres but you dont get the Rubino for speed. They are fairly low cost for a tubeless tyre, pretty reliable so far and they look as if they will do high miles. On wide rim the 28mm tyres only co.es up at 26.8mm which is why they probably loose on the comfort front a bit. These are pretty good tyres so far. They hold air well too.
Vittoria's other road tubeless tyres are best off with inner tubes in.
Vittoria do make some good MTB tyres however the ones I have used were branded Geax. Not tried there newer models.
Tyres in stock for testing are Verdestien Fortezza and Challange Pris Roubaix.
I might have forgot a few on the way. Oh here's one Dugast ORI tubeless tubular MTB tyres. Hopeless. I love dugast road tubulars but there MTB tyres have never lasted well. The ORI tyres are puncture prone in the extreme and sealant never seemed to help.
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Stans Alpha 340 rims would be lighter but they are crap rims. Tubeless tyres fall away from the rim without air making them impractical in the long run and tubed tyres dont always stay put at 100 psi. Kinlin XR200 rims are not tubeless compatible and are very narrow at 19mm wide. So these rims dont really meet the needs of customers anymore.
Mavic Yskion UST II tyres have been fitted. They look like the previous version and the previous version is fine, I that they grip well and are comfortable. Puncture resistance is fair and the hold air well being a UST tyre. They weight a claimed 260g each. With tape valves and tyres mass goes up to 1022g rear and 900g for the front.
They are reasinably stiff (compared to the wheels I normally build), light practical wheel. The hubs may be sub 200g for the pair but if you smear the supplied grease or equivalent over the freehub mechanism and a marine grease over the bearing seals you will get good bearing life. The hub maintenance is minimal and they require no special tool to maintain.
So if you want light and practical then get in touch. If you want the lightest clincher and sod practicality/reliability then there are other wheel builders. Although I build carbon tubular rimmed wheelset under 1000g. Those are proper light and I think tubs are practical.
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All Miche cassettes are manufactured in Italy. They are made from separate sprockets with no carriers. The steel plate is stamped then further machining work for the shifting ramps and cutouts are done. The last position 11 speed sprockets are available in aluminium which cuts mass abit.
Miche make the sprockets so they dont notch aluminium freehub bodies when the cassette lockring is torque to 40Nm to 50Nm. This also ensures the correct spacing. A torque wrench must be used. If you damage a lockring or thread it is simply due to poor fitting like cross threading, dirty threads or a poorly fitting tool. These things are easily avoided.
Miche sprockets are thicker than shimano sprockets which reduces there ability to notch an alloy freehub and increase sprocket stiffness which in turn improves shifting and decreases noise. Miche spacers are therefore thinner than Shimano spacers. This also applies to Campagnolo. So for 10 and 11 speed miche sprockets and spacers are not interchangeable with Shimano or Campagnolo sprockets and spacers. With 8 and 9 speed the difference is less important and good shifting can still be achieved with sprocket swaps.
The Cycle Clinic also stocks replacement sprockets and spacers so worn sprockets can be replaced without changing the whole cassette. This means if your like me and wear out a small group of sprockets and the rest have little wear then the Miche cassette is far less wasteful.
Shifting is as good as Shimano or Campagnolo cassette. Wear life is similar too. The cassette options I list are fixed. I don't offer customisation simply because I can get it wrong. I have to know what I am picking without having to refer to emails to pick and pack efficiently. Also most customs request will not shift as well.
I also dont list the cassette weights and have no interest in doing so. These cassette do weigh more than a shimano 105 cassette but have similar weight to a Campagnolo Centuar 11 speed casette if comparing the 11-32T. The reason is the construction. Campagnolo Centaur is made from separate steel sprockets but the 105 cassette uses a alloy carrier for the last three sprockets. So if you care about low weight dont buy the miche cassette but you also are accepting more freehub notching and throwing away cassettes before all the sprockets worn. Also shimano dont offer many ratio options.
One last reason to pick them is the ratios available. Youth racer can have a full range of gears with 14, 15 and 16t start 9, 10 and 11 speed cassettes for Shimano and Campagnolo. Also people who are not needing the 11 or 12t start sprockets can have a 13, 14, 15 or 16t start cassettes. Chains and sprockets wear more quickly on the smaller sprockets simply because the chain has to articulate (bend) more to drive them. On my commutor bike I use a 16-29t because it a heavy bike and 53-16t is the smallest gear I can reasonably use anyway. Chins last three times longer than with a 12-29t because of that 12 is available I use it even though I dont need to.
With miche start sprocket are 11t to 16t and finish sprockets 21t to 32t and 34t for shimano 11 speed.
Simply these are great sensible cassettes which dont try to flash and eye catching.
Here are my listings for complete cassettes. There are sprocket listing too in the cassettes section.
Campagnolo 8 speed/Miche M drive
Campagnolo 8 speed/Miche Mdrive for campagnolo 9/10/11/12 speed freehubs
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What is Ai (asymmetric stays)? Well put simply it is the drivetrain being moved 6mm to the right meaning the stays are no longer symmetric. This has the effect of changing the dish by 6mm. So wheels built for a bike with symmetric stays cannot be used in a bike with Ai. It is not possible to redish wheels either to acco.adte this standard as spoke lengths will be 1mm off. I wont do it other may but it's a mistake as its building potential problems for the wheel.
The upside is tensions are more even.
All disc brake wheels I build with the BORG DX hubs can be built for the AI standard. I can rebuild wheels built for symmetric stays with new spokes of the correct length for th AI standard. Some hubs may not be suitable due to there geometry but most rear hubs are suitable.
Ai bikes are all 12m TA.
I do dispute cannondale claim that radial and lateral wheel stifness increased by using Ai. Making spoke tensions even does not increase wheel stiffness. Lateral stiffnes is actually reduced by a couple of percent due to reduction in the left side bracing angle. The left side bracing angle contributed more to lateral stiffnes than the right side. That geometry and cant be argued with. Radial stiffness will be reduced as the right spoke bracing angle is increased. So the upto 60% claim in cookoo land territory. There is a weak link between tension balance and radial and lateral stiffness but since disc brake wheels have good tension balance to begin with the improvement of evening the tensions is very limited. In principle you can increase the loads required to detension spokes (often confused with stifness) but have tou tried loading a wheel till the spokes detension on Borg wheel. Not easy. So as with all thing take the marketing with a pinch of salt. However Cannondale use it and if you like there bikes using this design feature you need compatible wheels. The Cycle Clinic builds great wheels for these bikes.
From cannondale's website
The heart of the Scalpel-Si and F-Si System Integration is the all-new, Ai, asymmetrically offset rear triangle and drivetrain. The offset shifts the rear hub and drivetrain 6mm to the right, delivering super short chainstays without any of the usual compromises, and a rear wheel that is dramatically stiffer and stronger because the spoke tension and angles are equal on both sides. We then integrate this with our new Ai HollowGram spider, which moves the chainrings an equal 6mm to the right, balancing the system and maintaining perfect chain-line, shifting performance and Q-factor. This elegantly simple approach - Ai - enables us to have our cake and eat it too. The extra space created by shifting the drivetrain outboard enables us to have:
It started being used in 2017. Cannondale dont state on there website which model use this design feature. There catalogues do. The Cycle Clinic are not Cannondale dealers so it is not easy for us to identify which models have this feature. Before ordering please ensure your bike has Ai,this is best done with Cannondale or knowledgeable Cannondale dealer.
In the 2019 catalogue the SuperX, Jekyell 29 and 27.5, Scalpel SE and Scalpel Si used Ai. However there maybe other models too.
I have been stung once before with an american customer ordering wheels for Ai then using them briefly and returning them because they did not fit his bike. His credit card company forced a refund (I was going to refund anyway but no one like being forced to do something). Therefore it is important you check first. I like customers who trust me if they do I can help them.
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Let's start with a manufacturers recommended tyre pressure. These are not to used. The standards organisation has an approved test using a steel rim to se when a tyre blows off. Half that pressure is the recommended tyre pressure. It's a range due to variability but it's also way too high.
Back in 2015 when I got my first IRC tubeless RBCC tyres myself and others noted at 90 psi for a 25mm tyres (that sat at 27.5nm on a 19mm internal width rim) the tyre felt faster. What was described is zing however that road buzz is exactly what you dont want.
Road buzz is energy lost. You get this with wheels when manufacturers build a wheel that has zing. Smoothness is better. Smoothness is less energy lost. That's faster.
There is no relationship that works between rider weight and pressure as it far too dependent on road surfaces.
So to work out for a tubular tubeless or tubed clincher the correct pressure find a typical loop. Pick a starting pressure for a tubeless road tyre that's no more than 80 psi try it out. Your looking for smoothness I.e no buzz. Continue dropping until you feel tyre squirm in the bends
Squirm or pedal bob means the pressure is too low. The point at which there is no squirm and you have no road buzz that your min pressure and possibly the lowest rolling resistance. Your max pressure is just below the point where you start to feel road buzz. Rolling resistance
between these two points should not be that different but on most U.K road surfaces lower seems to be better.
This works for road, MTB, gravel or CX tyres of all types. The physics is the same.
For IRC road tyres and me 80 psi seems to be the point at which road buzz starts to become noticeable is 80 psi for a 28mm Formula Pro RBCC tyre. At 30 psi I cant really feel squirm but can bottom the tyre out. So 40 psi seems to be the minimum. 50to 60 psi is what I normally use now. With panniers I may push it up a bit. I am nearly 90kg kitted up and generally ride road biked 9 to 14kg in weight without extra load in panniers.
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Alloy nipples save a bit of weight but ha e a bad reputation. Yet alloy nipples failures are practically unheard of for me. I use Sapim HM washers so the nipple is easier to turn, Sapim nipple freeze stops galavanic corrosion or slows it to a crawl and thirdly my spokes are the correct length. Do all three and alloy nipes last.
Another detail is the spokes
Sapim CX-rays are used on the front wheel (nothing u usual there) but Sapim CX Force are used on the rear. This is a triple utted aero spoke. It not listed on the Sapim website as it's an OEM spoke. Its 2.18mm at the elbow and 2.2mmx1.3mm for the aero mid section.
Next are the hubs. Flange to flange distance is an overlooked miche hubs have 55mm flange to flange distance for the rear hubs. DT swiss have 50mm for comparison. That 5mm makes a big difference.
To improve tension balance a rim with a 3mm offset is used. Tension balance is therefore 53% which is not bad for an 11 speed hub. This mean even with tubeless tyres which cause a big tension drop (250N on the drive side) spokes will never go slack. Using A DT Swiss hub would result in high tension balance but a wheel that is less stiff laterally. So not only will the wheel feel less responsive but it wont be any more relaible because more spoke tension does not improve reliability. Spokes tension/lenght changes are the cause of fatigue when a wheel experiences load. A wheel that is less stiff experiences larger changes in spoke tension/length when the wheel is loaded. So just because DT Swiss or other hubs with a strong brand name does not mean it better.
Miche hubs also use big 6001C3 bearings with 2RS seals. They well sealed from the elements.
This makes for a very stiff wheelset with small aero advantage
They handle well and are comfortable. They also offer proper tubeless compatibility. By this I mean, tubeless tyres inflate easily and seat but they stay seated without air which is a critical feature. This makes selant top up easy and fix flats easier with a plug.
I try and think all this through so you dont ha e to and can enjoy the ride.
]]>So here is a detailed guide with some Physics. I used to be a physics teacher so I cant help my self.
A tyre , insert and air system is essesially a spring with an overal spring constant.So the Insert really acts as a way of giving more control of the air pressure required to give the spring constant needed to stop your tyres botming out and squirming.
Springs in series add in the following way. k(t) is the total spring constant of the system, k(a) is the spring contant of the air, k(r) spring contant of the rubber tyre and k(i) the spring contant of the insert. The spring contant of the air and tyre are non linear, I.e non co stant with respect to displacement which complicates matters
1/k(t) = 1/k(a) + 1/k(r) + 1/k(i)
or k(t) = [k(r)k(i) + k(a)k(i) + k(a)k(r)]/[k(a)k(r)k(i)]
Now it should be clear the tyre used has a big influence on the pressure that can be run.
The spring contant of the air (low pressure) is the lowest term so 1/k(a) is relatively high compared to the tyre and insert term which are lower. So for tyres with flexible casing the air term does not dominate as much as trail tyres with stiffer casings. i.e you can run lower pressures in tyres with stiffer sdiewalls then with tyres with more flexible sidewalls. That does not mean however that inserts only work best with tyres with stiff sidewalls. Thats not the case at all.
The insert is important. The firmer the insert the more dominatant the air term becomes. If you have a 1kg trail tyre you will need a firmer insert to run the lowest pressures. In the PTN range the Rokkline work well but the Revolution insert is best.
Run flat works best with stiffer tyres but the stiffer inserts (Rokkline and Revoluition) do allow run flat with light XC tyres. Most occasions where you will be running flat there will be some residual air pressure even if its 5 psi.
With a stiffer tyre and an insert the air term dominates again in other words you control the feel of the bike with small changes in air pressure.
The lower pressures can be be used allow lower rolling resistance. However the insert needs to reduce in size with air pressure and not be in contact with the tyre with the riders weight on it. Some insert are so big and stiff when the rider sits on them the tyre is in contact or the air volume so small (vittoria airliner) that there is very little tyre displacement before your tyre is in contact with the insert. That contact increases rolling resistance.
If the tyre is not in contact with the insert then the insert is the last line of defense when you and or strike an obsticle preventing the tyre bottoming out on the rim and the consequential damage that can result.
The lower tyre pressure improve grip and traction and as the tyre can conform to the gorund better you suffer lower vertical accelerations (bounced about less) and that is how rolling resistance is lowered.
Essentially these insert work. Come insert like Crush Core or the vittoria and geared more to gravity riding as they are dense and very impact resistant. Crush Core is also heavy compared to PTN. PTN actually have a new heavier (slightly) and firmer insert called rockline which is aimed at enduro riders and E bikes. . Schwalbe pro core is quite good as you can alter the spring rate of the inner chamber to tune the system. However I have punctured pro core with a long thorn. The firmer inserts are better suited to trail tyres and the lighter inserts are better suited to lighter tyres. Many of the other inserts are heavy or heavy and dont offer good inpact resistance. The is a good article on this here.
So this is a suspension system in the tyre and should be viewed as such. Sorry it got all technical.
What inserts do a summary.
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Play in Axle:this can be adjusted out. First make sure the end caps a tight. Use two 5mm allen keys and note the direction arrows on the left end cap. reverse thread alert.
Use a 2.0mm allen key to undo the grub screw on the left side. Use a 17mm spanner to adjust the bearing preload adjuster so there is just no play. screw down the grub screw. Be gentle with it as grub screws are easily rounded of. It only has to be secure so the adjuster does not unwind by itself.
The adjustment is best carried out with the wheel clamped by the QR in the frame as QR pressure loads the bearings.
Proceedure for the front and rear hub is the same.
Freehub change:
If you chanaging your freehub due to notching then so you cassette lockring up tighter. 40Nm is the minimum required. Miche cassettes also notch shimano pattern bodies less so there your other solution.
Undo the end caps with two 5mm aleen keys in each end cap noting the direction arrows on the left end cap. Remove the axle and change freehub.
Assembly is the reverse of disassembly but bearing preload may need to be set again.
Bearing Replacement
The freehub bearings can be replaced but most users will lack the bearing extraction tools to make this possible. walking the bearings out will likely damage the freehub or get the bearing stuck.
Main shell bearings should be extracted with bearing extracter or kocked out carefully. A bearing press should be used to press in new bearings. The Miche supplied 6001C3 bearing shoudl be used. a standard 6001 bearing will fit but will wear out faster because its not a clearance bearing.
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A 3.5mm Maxalami plug did fix the hole but the tyre developed a hernia and the plug pushes out above ~15psi. So I rode 8 miles home to swapped wheels. Incidentally the tyre still is inflated to that pressure 24 hrs later and it would have got me further.
I bring this up because I get the odd email about this sort of failure from time to time. The customer normally find the tyre fails without warning and thinks its the tyres fault. That's unlikely but hitting a stone or pothole at some point and thinking all is well is likely. This can weaken the tyre and it then fails at a later date.
These failures do happen to other brands of tyres too. IRC normally replace the tyre even though it strictly is not a warranty. The Formula Pro X-Guard tyre due to the puncture protection belt does seem to fail seem to fail so if you ride on back lanes that are full of holes or venture down bridleways/gravel sometimes the X-Guard tyres are a better bet.
The IRC Formula Pro RBCC is a race tyre and while normally long lived and reliable they are not invunerable and more easily damaged than its hardier brother. This however this is the case with all race tyres. We all want nice fast rolling tyres but in reality these are racing tyres.
A weakened tyre should have telltale bulges or other deformaties. Tubeless tyres are should therefore be inspected. Just because it's holding air dies not mean all is well. The moral is check your tyres.
My failure did happen after I spent a few rides bouncing down bridleways. Did this weaken the tyre, I don't know. I did hit the stone fast and just before I hit it I did think that's looks sharp and I hope... Bang.
The other morale is carry Maxalami plugs. There is nothing that can't be fixed even if it temporary, that is fixable with these plugs. A tube is not the answer as there is no way you'll get a boot to stay put just above the bead when mounting the tyre.
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Why 2:1 lacing? Well it's been around for a while .Ford used it in the early 20th century in car wheels. It is a lacing pattern where the spoke tensions are more equal than in a conventional wheel. This reduces the stress in-balance around the spoke holes so rims are less likely to crack. Also the reduces the difference in loads on the rim actually increases radial stiffness. In addition there are 16 spokes on the DS at low bracing angle which contribute more to radial stiffness than the non drive side spokes. Torsional stiffness can so be higher given there are 16 spokes drive side which can be laced 3x and therefore tangential to the hub flange. So if done right spoke life can be extended.
It started in 2015 and for my 40th birthday I ordered a set of Royce UK Titanium carbon hubs. These have Titanium flanges, carbon fibre shell, Titanium axles, Titanium freehub body..... Rather special. I did however specify a geometry for 2:1 lacing. So that's a 24h rear hub (20h front) with 16 spokes DS and 8 spokes non drive side. 9 months later they arrived and they were built into a set of wheel I still ride today using Pacenti rims. The Sl23 V1 rim was crack prone. This set has not cracked the reason is simple, the 2:1 lacing means more even spoke tension and that reduces the stress differences caused by the loads placed by the spokes on the rim and that in turn reduces the fatigue rate.
The wheels feel great and the hub offers a 74% tension balance. These wheels are on my winter bike. The basics design was therefore proved.
Now to the geometry and a bit of physics.
2:1 lacing is not something that can be done with any hub. It needs specific geometry. The reason is the 8 NDS spokes. More than 50% of the lateral stiffness imparted by the spoke comes from the non drive side spokes due to the higher non drive side bracing angle.
(Source whosatthewheel)
This means a a 2:1 hub with conventional geometry will build into a wheel with lower lateral stiffness than if the wheel is laced conventionally. That not good for how the wheel feels or for spoke life. Brake rub is more likely.
To avoid this the non drive flange has to be pushed out much further than you normally see. 45mm from centre is the tipping point compared to a conventional 11 speed hub like the Shimano hubs where by there is no loss in lateral stiffness. My Royce UK hubs have NDS flange 46mm from centre and the DS flange 17mm from centre. This reduces the tension balance so for the Royce hubs with a symmetric Pacenti SL23 rim its it 74%. Asymmetric rims increase the tension balance. Kinlin rims have an offset of 3mm. So BORG 2:1 hubs have
DS flange 16.4mm from centre PCD 54mm - derailleur clearance seems to be good for Shimano 11 speed. Testing progress for SRAM 11 speed. Campagnolo 11 speed has forced the DS fange to moved in board by 1mm so the cassette clears the flange.
NDS flange 49mm from centre PCD 44mm
OLD 131mm (the one mm increase has been used on the DS flange to push it out).
Tension balance is 87% with a offset Kinlin rim or 70% with a symmetric rim.
The bearing are the best NTN. NTN bearings sold as normall class are normally class 4 or better. The bearing class are normal class, class 6, class 5, class 4 then class 2. Class 2 has the tightest dimensional tollerances. Bearing you buy of the shelf will be normal class and can therefore have much greater variation in OD and ID than the NTN bearings. So NTN bearings are simply the best. That means long bearing life. The seals are the contacting LLU. While non contacting bearings are often used in bicycle hubs so the wheel spins more freely in the stand in reality the difference in drag between the two types of seal at 30kphwith rider load is less than 1W which nowt. The whole reason is above 60rpm the seals lift due to air pressure variations caused by rotation. That 5mph for a road bike with a 2.2km rolling diameter. So bearing drag form the LLU seals simply falls away at riding speeds. Bearing life is reduced with non contracting LLB seals and worn bearings have higher drag. If the LLU (contacting) and LLB non contacting seals are compared for drag at 30 kph the saving is small (5%). Drag from seals varies with speed and load in a non linear way. The faster the bearing spin the smaller the difference. Hense non contating seals wont be offered. How a hub spins in your hand or in the frame with no load on it is no guide to how is roll on the road. What seems obvious really isn't.
The rear hub has 2x 61902 bearings and the freehub 2x 6802 bearing running on a 15mm axle. The freehub has 4 pawls and a 36T ratchet ring. This means fast engagement but the large diameter ring means a low rate of wear on the ring and pawls.
Freehubs for Shimano 9/10/11 speed Campagnolo 9/111/12 speed and XDR 11/12 speed will be available.
The front hub has a 69mm flange separation distance and 38mm PCD. 6901 NTN with LLU contacting seals are used.
A full range of spares will be kept along with the bearings which are bars to find in the U.K. use of more readily available bearings will lead to shorter bearing life. A limited number of hubs with non contacting seals maybe made available but bearing will be shorter and I wonder what the point would be. You won't finish your ride any faster.
The rims that I will use are Kinlin XR26T and XR26RT asymmetric for the rear. My instincts were correct this rim is perfect for this hub. There will be a Carbon rim too. A 55mm deep 25mm wide rim drilled for this hub only.
Any centre drilled rim is suitable for 2:1 lacing but deep rims need to be drilled for the rim to minimise spoke bends at the nipples on the non drive side.
The price of the hubs is expected to be £200/pair. Weight is 266g for the rear and 122g for the front. The hubs will be available to the trade. Availability from later 2019 assuming there are no issues which need addressing.
The test wheels (BORG26) are tubeless compatible and shod with IRC Formula Pro RBCC tubeless tyres. Bare weight is 1600g and use Sapim Force spokes for the rear wheel and Sapim Laser for the front. These might be replaced with Sapim CX-Force and Sapim Cx-Rays or that option offered when retail begins.
Tension balance is 1280N/1180N = 92 to 93%
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In my opinion no tyre should be used with these rims. I noticed this 18 months ago but I refrained from publishing due to lack of proof (sample size too small). Some warranties for IRC tyres on these rims have cropped up.
If you suffer a tyre failure on an ENVE rim I therefore cannot consider a warranty issue. Your tyre maybe replaced as good will but in my opinion you should be returning your wheels to ENVE for a refund.
I think there are issues with DT Swiss road rims too but that is due to the size of the bead hook (too small) and the wrong orientation. Tyres with reinforcement at the bead are best used.
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24hrs later the tyre is holding 90 psi just fine.
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This set is built with bitex RAF/RAR12 hubs and Sapim CX-rays to create a 1360g wheelset in 20F/24R spoke count. That's enough for the riders if 650c wheels.
Cost £408
]]>So take one pair of SCS hubs in 24h drilling and lace them to the BORG45disc to create the BORG45 DISC SCS.
This set with tape and valves is 1745g. So that's approx 100g more than the standard wheelset with the BORG DX hubs but the customer now has wheel that are useable.
If what you need is not listed give me a bell. There is normally a solution.
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Gravel and XC MTB riding are similar enough that rims should be no different.
The BORG30 is light, stiff and fun to ride.
Wheelset weight with Sapim Force spokes and BORG DX hubs is 1450g.
The rims are tubeless compatible and hookless. Tubed tyres can be used but why would you want to. The internal width of the rim is 25mm. External width is 30mm.
Gravel wheels are not aero wheels. 40mm tyres put a kybosh on that so it should have round spokes. Also ditch the need for aero rims a wide shallow rim can be used. With the right profile this can still be radially and laterally stiff.
The hubs are 12mm thru axle compatible and reliable. They are made for centrelock rotors but 6 bolt adapters are available.
One important aspect of tubeless compatibility mean to me a tyre that will remain seated with no air pressure. The BORG30 passes that test. This means once a cut is sealed with tyre plugs or sealant you can reinflate with a hand pump. The wheel can be used with inner tubes but I can't think why you would do that to yourself.
Enter the BORG30.
IRC Formula Pro tubeless tyres like the Formula Pro X guard and the Formula Pro RBCC tubeless tyres have a harder compound in the the centre section. The shoulders have a softer compound as this area suffers less wear. The shoulders use a file tread pattern to improve wet grip (I am not sure on the exact reasons why but IRC do insist that the thread pattern works).
The pictures of the front and rear Formula Pro RBCC are from a tyre after 1900km. The rider weighs 112kg and wrote the reviews.
Front tyre showing little wear.
The rear tyre showing more wear but the thread depth marker is still visible. This tyre is not worn yet.
Riders that ride in straight lines in the Fens get alot of miles out of most tyres.
Riders that put out alot of power tend to wear rear tyres fasters.
Heavy riders wear tyre more quickly,
Wider tyres tend to last a bit longer as the contact pattch is bigger.
Riders that climb alot tend to show faster rates of wear.
How the tyre wears is a good indicator of the suitability of the pressures used. The photograph of the rear tyre show a tyre wearing evenly. The pressure used is correct (this load dependent). If the pressure is too high if the centre wears only. If the pressure is too low you will see premature squaring off and wear in to far into the chevrons.
Tyres also get damaged by UV light and will crack. Natural rubber tends to crack more than artifical rubbers so don't store your bike in sunlight. Ozone also affects tyres and again they craze. So avoid Ozone exposure.
So how long to they last. Well for me quite a long time. On my commuter bike, a Genesis Equilibrium disc Ti with two rear Ortleb panniers (bikes weighs 15kg) and all 86 kg of me a IRC Formula Pro RBCC or X-Guard tyres on the rear wheel lasts 6000-7000km.
If you get less than me mileage wise then the above will explain why.
]]>Most aero tests have issues. A wheel or a wheel in a bike is tested with or without a dummy or rider. Sometimes with half a dummy. All these differences affect the significance of the overall result as it is impossible to tell the overall effect of the wheel in the system as a whole. Not to mention the air flow around the wheel is affected by the presence of a fork or the absences of it.
Sometimes the wheels are static and a spinning wheel behaves differently to a static one.
The final problem and this is a big one all aero tests you see are done by running the air flow at 50kph for a time at a static angle. Stop recalibrate and reset at the next increment. This does not predict real world conditions
As you ride the bike rocks, the front wheel and changes direction constantly. The changes in direction are small but if the front wheel did not do this you would fall over. Also when you pass gaps in hedge rows or buildings, even when cars pass on busy roads the airflow will osscilate sometimes widely.
Most wind tunnels don't simulate osscilating airflow. All this, means the results from most wheel aero tests are not that informative because the wheel behaves quite differently when the airflow oscillates and therefore behave differently in the real world. For starters you can spot the wheels that are at risk of speed wobble this way.
So when an engineer at airbus started testing wheels in there wind tunnel as an after hours project my ears pricked up. First the protocol has the air flow ramping up from zero degrees and holding at an angle for 15secs but oscillating +/- 2.5 degrees. A wheel is in a bike with a rider on it. The test is consistent for all wheels.
The error is +/- 2.5%
The protocol was determined by 6 month of rider monitoring.
The above data is from the test rider riding down a straight road in the west country at constant speed. The yaw angle is anything but constant.
So from lots of data gathered on yaw angle vs speed gathered from time trailists averaging 50 mph and road cyclist average 30 kph a protocol has been determined. The protocol does not represent one ride or how your wheels perform on a particular ride under certain wind conditions. What it does is sum wind conditions experienced over 6 month of U.K riding and therefore simulates how your wheel performs over a wide range of condition that would be experienced riding the wheels over a whole year. So this is more like giving a car mpg figure but for a bike.
The test is conducted with a rider on a road bike (the same bike and rider) in a road position (on the hoods). Below is an exaomple of one of the test protocols.
The testing protocol is very different to manufacturer tests. It mimics real world riding conditions in the sense it models transient (oscilating) air movement. Emphasis is placed on wheels which handle the separation and reattachment of airflow efficiently, very little emphasis is placed on riding a bike straight into a head wind at zero degree yaw - this is not realistic so why bother testing it. The wind tunnel used was temperature and humidity controlled.
The results
The figues for the BORG50C wheel with the reference Continental GP4000sII 23mm tyres fitted is 186W at 30 kph and 597W at 50 kph. I dont know about you I can't hold 50 kph on my road bike for very long. the 600W output for me is quite realistic. Remember the error is 2.5% so at 30 kph, the error is 4.675W so frankly the wheels that test better are within the margin of error. Also what is clear depth is king. Although profile is important too.
So at 30kph all the wheels in the from about 183W to 186W are as good as each other. Cost spares availability, ease and cost of repair do vary though.
If the rim is two blunt that increases drag although cross wind stability maybe better.
What the detailed results show is most wheels show speration of air flow at 12 degrees yaw. The BORG50C is no different. That's physics. Some blunt profiles can extend this to 14 or 15 degrees but at the expense of drag. Those blunt wheels have one big problem once the airflow seperates it does not reattach well.
What is shown in the detailed results is some wheels deal with the air flow flutter better than others. Mine do quite well, the wheels that don't deal with it poorly. Thats down to the profile.
So in short for £800 the BORG50C is really a very good wheelset and has all the charastistics you need. It also benefits from a life of the rim warranty against faigue failures and manufacturing defects. The wheels are repairable as every spare is available and I will do it here for sensible money.
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