Let’s do it better this time!
What is currently happening with the new 32-inch supersize wheels is exactly what we went through nearly 20 years ago during the transition from 26 to 29 inches. Out of initial experimentation, combined with a few missteps, unified standards only developed over several years. There is a good reason why today’s 29er MTBs all roll across the trails with wider flange spacing. Boost hubs - and in some cases, even Super Boost hubs - were the means to an end to compensate for the reduced wheel stiffness compared to 26-inch wheels.
Now, the same problem is knocking on the door with the jump from 29 to 32 inches. Quite literally, as a look at the standardized ETRTO measurements reveals. While the jump from 26 to 29 inches was 63 millimeters, this time it is 64 millimeters from 29 to 32 inches. However, „bigger“ doesn’t just mean more speed; unfortunately, it also means more weight and, on top of that, less stiffness. These „big wheels“ flex a significant 31 percent more under the same lateral load.
But aren’t current 29-inch wheels already too stiff anyway? Why else would enduro and downhill racers be using every trick in the book to remove stiffness from wheels to improve handling characteristics? That may be true for some. However, not every athlete weighs under 80 or even 70 kg and has a dedicated team of mechanics happy to lace up a handful of new wheels over a race weekend. E-MTBs with permissible total system weights of up to 150 kg are a common reality and stress wheels more than you might think. 32-inch wheels should be prepared for this scenario as well, rather than focusing only on lightweight riders with gravel and cross-country aspirations.
But how stiff is optimal, and when does a wheel become too soft? Our extensive field tests have shown that lateral stiffness should not fall below a certain value to maintain a precise, controllable ride feel. On the test bench, this limit can be defined as 8.5 mm of deflection under a lateral load of 300 Newtons.