It's the big topic in the mountainbike scene: 32 inches.
Since tire brand Maxxis unveiled an extra-large version of its Aspen race model at the 2025 Eurobike trade show, there has been heated debate. Is 32 inches the next big thing?
Only time will tell. As wheel specialists, we experimented with 32 inches early on and are convinced of the advantages of large wheels.
The 32-inch version of our proven BITURBO wheel does not just have a larger diameter. It has been optimized all around for the new size. It features a special carbon layup that combines lateral stiffness and comfort. Pedaling power is converted into propulsion without compromise, while road shocks are filtered out.
The 32-inch version of our proven BITURBO wheel does not just have a larger diameter. It has been optimized all around for the new size. It features a special carbon layup that combines lateral stiffness and comfort. Pedaling power is converted into speed without compromise, while road shocks are filtered out. Another special feature is the patented SAFEWING rim design. This ensures perfect tire support and protects the carcass from damage in the event of punctures with its rounded rim shoulder. The SAFEWING design allows you to ride with lower air pressure. This increases grip and safety.
Because the BITURBO wheel is not under tension when standing still due to its monocoque construction, the rim area can be made about 30 percent lighter compared to spoked wheels. Without compromising on strength. This guarantees top acceleration.
Classic rims are under enormous spoke tension and must be reinforced accordingly.
The BITURBO X 32 SAFEWING is the result of intensive development work. We began working extensively with 32 inches back in the summer of 2025. Initially out of pure curiosity, but after initial tests with a specially built experimental prototype bike, we were ultimately convinced.
Rollover performance and grip were noticeably better than with 29-inch wheels. At least, that was the testers' impression. To obtain precise data on the difference between 29-inch and 32-inch wheels, we conducted an extensive study together with the test specialists from Ride Better Bikes. The experimental prototype was ideal for a perfect comparison. One identical bike, two wheel sizes.
Even the tire model was the same. The Maxxis Aspen 29x2.4 and the Maxxis Aspen 32x2.4 were used.
During the test, acceleration values were measured on a test bench and differences in comfort were determined on a bumpy track with the help of acceleration sensors. The following test on a race course divided into segments produced interesting findings. The poorer acceleration of 32-inch wheels is almost completely offset by the extra grip on uphill sections.
On the downhill trail, the large wheels were the clear winners. The hardtail was significantly faster with 32-inch wheels than with a 29-inch setup. It was on the same level as the 29-inch race full-suspension bike, which was used as a reference in all tests.
As a manufacturer, we can respond quickly to trends. Every step is taken under one roof, from development to 3D printing, prototype construction, and manufacturing. That's why we were able to bring the BITURBO X 32 SAFEWING to series production in such a short time. The Swiss brand Stoll Bikes also provided important input. Founder and CEO Thomas Stoll, who was an active elite racer for many years, experimented with 32 inches early on. The innovative Stoll P32 carbon full-suspension bike, which has now been launched, marks a new era in MTB racing. The frame is manufactured at our factory in Würzburg. The BITURBO X 32 SAFEWING are the perfect wheels for the bike. The two brands have been working closely together for years.
On May 9, Bike Ahead and Stoll Bikes are organizing a test day in Würzburg. The Stoll P32 and the BITURBO X 32 SAFEWING can be tested there.
Information about the test day is available at www.stoll-bikes.com
