Moots partner with WTB Is this the future wheels size for gravel bikes

Jun 06, 2023

Moots have collaborated with WTB on this project to make a prototype 750d wheel and tyre combo

American brand Moots has paired up with tyre manufacturer WTB to create a new larger diameter wheel size

Junior Tech Writer

At the recent SBT GRVL race that took place in Colorado, and just ahead of the MADE bike show, Moots had something new on display: a prototype bike, with a new wheel size.

The Moots Routt CRDD prototype gravel bike is built around 750d wheels, with the rims coming in at 30 inches in diameter. With gravel tyres fitted, the outer diameter of the tyre ends up being a pretty similar size to a 29 inch mountain bike tyre.

Moots have collaborated with WTB on this project, with WTB manufacturing both the prototype 750d rims as well as the tyres the bike is running on. It looks like WTB is the only manufacturer of this tyre size, and in this case it was their Nano Raptor gravel tyres on display in the new, larger size.

The rationale behind the move to bigger wheels and tyres is twofold. For starters, the larger wheel and tyre combo allows for the same-width tyre to have higher volume and rolling capacity on rough terrain.

Although a 700c gravel tyre and a 29 inch mountain bike tyre fit on to the same size rim (both tyres mount onto 700c rims) the overall system diameter of the 29 inch mountain bike tyre is considerably larger once the profile of the tyre itself is considered.

The Moots CRDD uses 750d wheels to give an overall system diameter that is comparable to a 29er mountain bike system

By upping the diameter of the gravel bike to 700d, the overall system diameter of a gravel wheel and tyre are more closely aligned with the 29 inch mountain bike.

Much like we saw when mountain bikes moved from 26 to 29 inch wheels, the larger diameter will roll over the rough stuff a little bit easier, and faster.

Secondly, the larger wheel size will allow bikes to be designed more appropriately for taller riders. We've seen brands use 650b wheels for their smallest bikes for some time, so it seems natural that they'd offer a comparable option for riders at the other end of the size spectrum.

With a more appropriate sized wheel designers can retain the same geometry and proportions across all sizes: a very small frame with a 700c wheel, for example, requires the head angle to be slackened for it to fit and therefore compromises the intended feel on the bike on the road.

There is currently no production timescale for this to become a consumer reality. Until bike manufacturers decide that this is an avenue they would like to pursue beyond the prototype stage, it seems likely this will remain a novelty.

For the time being this will remain as a prototype by both brands, with WTB claiming they are capable of production if the need ever develops

If nothing else, this is a great experiment into tailoring wheel sizes for different-size riders and will hopefully allow for consistent bike design and ride characteristics across a whole platform. Not only that, but with the improvements to rolling resistance, this new technology could push the efficiency and speed of gravel bikes, especially on the rougher end of the gravel spectrum.

To see which is the ultimate do it all bike check out Si and Isaac put a gravel bike head to head with a mountain bike here.