Giant tyres: Are 32-inch wheels taking over the cross-country segment?

The idea of equipping mountain bikes with 32-inch wheels has been floating around development departments and internet forums for years - but for a long time nobody took it seriously. The consensus was that they were too bulky, too heavy and too unrealistic for practical use. But that all changed in one fell swoop: Faction Bike Studio presented its Big Ben concept bike at Eurobike 2025 - impressively demonstrating what is possible with the new giant bikes. The second sensation was not long in coming either: last weekend, a BMC prototype was spotted on the race track during training at the XC World Cup in Andorra.

The Big Ben - a statement on two wheels

With the Big Ben, Faction Bike Studio shows at Eurobike where the hammer hangs - and where the trend is heading. Maxxis has fitted its standard 32-inch Aspen tyres to the no-name wheels of the concept full-suspension. Now that we've seen a serious full-suspension bike with these giant wheels for the first time, it's clear that this is no longer a marketing stunt. Insiders are even reporting the first tests by well-known XC professionals - all of whom are apparently delighted with the improved traction and superior rollover behaviour. The key data of the Big Ben: 120 millimetres of suspension travel, a main frame made of aluminium tubes and lugs - manufactured in Canada.

Update: The first 32-incher in the World Cup!

The frame of the BMC prototype looks like something from an experimental laboratory: carbon tubes glued into milled aluminium sleeves. However, the generous tube connections, the horizontally mounted shock, the extended fork and the fact that there is hardly any room for a water bottle in the frame triangle indicate that the concept is still in its infancy. Also exciting: the stem clamps above and below the head tube - presumably because a normal stem would not provide enough drop to get the front low enough. Wow!

Why 32 inches at all?

• Better rollover behaviour: Roots, stones, edges? The bigger the wheel, the easier and faster you can roll over it.
• More traction: Larger tyre circumference = more contact area = more grip. This can be decisive, especially on loose surfaces. wrong
• Fast for longer: Due to the higher inertia of the large wheels, the 32-inch tyres keep you going for longer. In rough sections, you are more likely to be "carried" over obstacles.
• Lower centre of gravity: Larger wheels lower the body's centre of gravity in relation to the axle height - and thus improve rollover behaviour. Why?
  Because with a lower centre of gravity, the bike is more likely to push over obstacles from behind instead of pushing against them with a high centre of gravity.

What speaks against it?

• Frame geometry: New frame concepts are needed to accommodate 32-inch wheels. Smaller riders in particular could have problems with stack and standover height. The chainstays also need to be longer to make room for the wheel lift curve.
• Weight: More material, more mass. This is a critical adjustment screw, especially for wheels. The larger diameter noticeably increases the rotating mass - this costs significantly more grit when pedalling.
• Manoeuvrability: The bigger the bike, the more sluggish the handling - this requires more pressure in tight bends and key sections
• Stiffness: Wheel manufacturers are faced with the challenge of achieving the same stiffness - and therefore the same efficiency - with the larger wheels as with 29-inch wheels.

A look back: the evolution of wheel sizes

The history of MTB wheels is characterised by trial and error, but also by bold progress. In the 90s, 26 inches was the standard. Agile, light, proven. Then, in the 2000s, the first 29-inch bikes came onto the market - initially ridiculed, then loved for their better rollover behaviour. A few years later, 27.5-inch bikes came along - as a compromise for bikes with more suspension travel. Later on, XC pros such as Nino Schurter rolled through the XC World Cup on the intermediate size.

Today, 29 inches is the XC standard, but even here you reach the limits. And that's where 32-inch tyres come into play. What once sounded absurd is now backed up by real bikes - such as the Big Ben or the prototype from BMC. The development is very reminiscent of the switch from 26 to 29 inches around 15 years ago.

Is the 32-inch revolution coming?

The answer: maybe. The segment is still a tender seedling, not mainstream. But what Faction and BMC are doing is more than just a PR stunt. If large manufacturers jump on the bandwagon and suitable components become available (keyword: wheels, forks, tyres), the niche trend could become a serious market - especially in the cross-country sector.