The Open Pro has been around for a while. It is narrow and shallow and like my car ( a BMW from 1988) was great once and still is in an old fashioned way but technology and design has moved on. Sometimes new designs are rubbish and offer so much promise but deliver disappointment however this new rim from mavic (I will be getting the first drop on 4th July) promises much more. 

Mavic have tried to standardise UST - that is tubeless so tubeless tyres fit easily and inflate easily (this is not always the case) and tubed tyre should be mountable with relative ease.

Mavic claim much tighter tolerances than other rims have although I have found Kinlin's with IRC tubeless tyres to be very consistant and this will be my reference standard when testing. 

Mavic do have a tubeless tyre of there own. This wont be out till August. I have some on back order. I will be testing these tyres throughly and Mavic rims with IRC tubeless tyres. 

If I find the Mavic UST tyre to have longevity issues (if it does I will find it I am a tyre killer) then they will not be offered for sale by me. If I find IRC tyres are an easy mount and cause no issues then I will happily suggest them. Speaking to Mavic about tyre fitting they indicate there warning are more about ease of fitting than safety. If they tyre fits reasonably tightly then it will be safe. Issues only come with tyre that are a bit loose. 

Internal width is 19mm no exalith version this year and weight is a claimed 430g. 

I have 24H, 28H and 32H rims being delivered on the 4th July. So this listing is active now. Grab pair or add you wheels to the build queue. I need to build wheels up and I would would like those first customers to give me feedback about tyre instalation and general experiences (ride by in fact if you can) as this will all be useful information for such a new rim.