Is 750d the future of gravel biking? Or are the recently spotted prototype Moots/WTB wheels just a marketing gimmick?

Close up on a Moots CRD gravel bike
Moots have a prototype version of their CRD fitted with new wheel sizing (Image credit: Moots)

A new Moots gravel bike has been spotted at SBT GRVL in Steamboat Springs, Colorado. In a video posted by Ben Delaney on his The Ride YouTube channel, eagle-eyed Delaney spotted the American bike manufacturer renowned for their titanium frames had their newly released titanium Routt CRD gravel bike equipped with custom 750d WTB wheel rims and 40mm Nano Raptor tires. The new prototype Moots called the Routt CR-DD.

Judging by the comments on the YouTube post, the new wheel size has certainly divided opinion, but will the 750d size ever make it to production? Possibly this passion project between Moots and WTB is just some cunning marketing designed to boost attention for the brands in advance of this weekend's MADE Bike Show.

It's certainly not the first time WTB has dropped a new wheel size. Back in 1999 at Interbike, they launched the first 29-inch tire on a custom WTB bike designed to run their 29 x 2.1-inch Nano Raptor tire.

Two 650b wheels with Challenge Tires

700c and 650b are the current standard in gravel wheel sizing (Image credit: Paul Brett)

Why do I need bigger wheels?

The best gravel bike races are not much slower than some road races these days. Keegan Swenson won SBT GRVL in an astonishing time of five hours and fifty-seven minutes over the 229 km course. In theory, a larger gravel wheel could produce more speed and possibly roll better on certain terrain. So 750d wheels could give an advantage for riders trying to keep up with Swenson. It also could provide exceptionally tall riders with another wheel sizing option. However, there would also be frame geometry and equipment issues to work around.

Keegan Swenson riding under the SBT GRVL finish line

Swenson won SBT GRVL in a record time. Would a bigger wheel make you quicker? (Image credit: SBT GRVL)

Our colleagues over at Cyclingnews reached out to WTB, who provided more information on the new setup and any potential production of 750d.

"Innovated and driven by Mark Slate (co-founder), WTB has developed a large diameter 750d tire and rim that currently only fits custom-built-to-spec bikes. WTB is constantly prototyping to determine the next advancement in bike technology, but there is currently no production timeline for 750d. Our plans to move forward are dictated by brands' interests in this new wheel size."

"If brands begin manufacturing and spec-ing bikes that accommodate 750d tires, then we will have the opportunity to move forward with the project. There are no plans to offer 750d products aftermarket until there is OEM spec. We'll be ready if that moment comes. Until then, enjoy this sneak peek behind the curtain and we'll continue to roll with the diameters currently in the market."

So it's unlikely for now that the Moots/WTB collaboration will become much more than a passion project. But you never know, as mentioned it's divided opinion but also brought plenty of attention to Moots and WTB. For anyone going to the MADE Bike Show in Portland this weekend, the Moots prototype will be on show at the brand's stand.

Paul Brett
Staff writer

Paul Brett is a staff writer for He has been an avid cyclist for as long as he can remember, initially catching the mountain biking bug in the 1990s, and raced mountain bikes for over a decade before injury cut short a glittering career. He’s since developed an obsession for gravel riding and recently has dabbled in the dark art of cyclocross. A fan of the idea of bikepacking he has occasionally got involved and has ridden routes like the North Coast 500, Scotland and the Via Francigena (Pilgrim Route), Italy.

Current rides: Marin Alpine Trail 2, Ribble 725, Cube Stereo 160

Height: 175cm