Gravel Grinder News: 750D: Another New Wheel Size?

Gravel Grinder News: 750D: Another New Wheel Size? – by Guitar Ted

Image of a white bicycle in a mountainous region featuring 750D wheels and tires.
Mark Slate’s personal 750D wheeled bike

The other day our contributor to Riding Gravel, Grannygear, sent me a text with a video link and his message was “Wow! 750D?“.

I investigated my files, because this designation for a wheel size sounded vaguely familiar to me for some strange reason. As it turns out, I was told in confidence early in 2018 that there was a wheel size being tested by Mark Slate of WTB which was being called alternately “750D”, or “29.5”. Actually, it was told to me by Mark Slate himself, so I was sure that this was no hoax. This was a real thing.

Mark and I had an email thread going considering what the ramifications of such a wheel for gravel might be. I was sent several images showing the bike and the difference between 700c and this new 750D size. In technical terms, 700c is ISO 622 diameter. This new wheel? It was ISO 660!

An image shared with GT from Mark Slate in 2018. The 750D is on the left, 700c on the right. Both tires are 40mm and the rims are identical inner widths.

The news came out now with a video posted by Ben Delaney of “The Ride” on You Tube. (Link) In that video, it is revealed that Moots has a bike set up with a set of WTB wheels and tires on a bike Moots fabricated to show off the wheel size. The Moots representative indicates that 750D might be the size for the taller riders out there.

While that could be, it is interesting to note that the overall diameter of the 750D wheel isn’t far off from a 29″er MTB wheel with a meaty tire and bicycles with those wheels fit a lot of various sized people. So, I wouldn’t write this off as something “just for tall people“.

Will this become a thing? You can bet that if WTB has a wheel set floating around out there with Moots that there are a whole lot more of those wheels and tires somewhere….. Where they show up, and when is anyone’s guess right now, but I think it is safe to say that will happen sooner than later, and this will become a new choice for gravel riders soon.

Stay tuned….

Guitar Ted would like to thank WTB’s Mark Slate for sharing the technical details concerning the 750D wheel standard.


Author: Guitar Ted

Guitar Ted hails from Iowa. Home of over 70,000 miles of gravel and back roads. An inaugural member of the Gravel Cycling Hall of Fame and Co-creator of Trans Iowa in late 2004- Guitar Ted has been at the forefront of the growth of gravel events and riding since then. Creator of Gravel Grinder News in 2008, he produced the premier calendar of gravel and back road events. GT joined forces with Riding Gravel in late 2014.

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5 thoughts on “Gravel Grinder News: 750D: Another New Wheel Size?

  1. Not another unnecessary “Standard”!
    Up to now the wheels are interchangable to road bikes, so to transform your gravel into a road bike you only change the wheelset. The gravel bike uses hubs from the road bike, either small mtb rims or wide road bike rims, they share the spokes etc. But on a ETRTO660 no dealer has a single spoke because the required length is beyond 305mm.

    1. @Rene’ Grossl – Again, as I responded to Jeff – If this is a stupid idea, it will go away quickly. The industry has the capability to make spokes, so that’s not an issue IF this idea goes forward. They make spokes for 36’ers, so there you go…. Dealers have choices to stock or not. Try getting proprietary spokes like Industry 9 spokes at most dealers without ordering them. This hasn’t stopped I-9 wheels from being popular.

  2. i don’t understand why they made another standard.? Nextie and alchemist already make 32er carbon rims that are 686 BSD. why not just go with something that is already in production rather than make another wheel size. plus the unicycle crowd would be an instant customer since the tires available are very limited currently. this seems like another protectionist move by a bike company to lock you into “their” system. very annoying that they do this stuff.

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