Last October we briefly discussed the growing popularity of bikes with mixed-wheel sizing. We saw top racers such as Danny Hart, Loic Bruni, Finn Iles and Martin Maes all experimenting, even winning, with 29-inch-front- and 27.5-inch-rear-wheel setups. Mixed-wheel bikes, mismatched bikes, party-in-the-back/business-in-the front bikes, and even Franken-bikes—call them what you will, these mountain bikes are a hot topic in 2020. This new fashion is here to stay, but the questions remain, “Is it right for me? Is this that much of a game-changer for me to convert?” Here is a quick breakdown of what we have discovered so far.
1. SNAPPY, MORE RESPONSIVE HANDLING
With more and more Enduro World Series events involving the kind of technical track conditions you might see at a World Cup downhill race, a number of riders have switched over to mixed-wheel bikes. Riders Martin Maes and Cody Kelly have been running a smaller wheel in the rear for the series. They believe it makes maneuvering around obstacles easier because the smaller rear wheel’s reduced turn-in radius allows the bike to turn with less effort. Riders claim the bikes have a more pinpoint response, and it’s much easier to maneuver the rear end when tackling demanding terrain. Now, of course, we are talking fractions of seconds saved for these racers, but that could mean the difference between a podium and going home empty-handed.
2. LETTING THE CAT OUT OF THE BAG—THEY ACCELERATE QUICKER
It’s a simple law of physics that a smaller wheel will accelerate faster than a larger wheel. A 29-inch wheel has a larger radius from the hub, creating greater rotational mass that results in slower acceleration than with a 27.5-inch wheel. A larger wheel is simply harder to get moving. Having to expend less effort to get the bike moving forward will mean power saved for the rest of the trail ahead. On the other hand, a 29-inch wheel requires less effort to maintain momentum once up to speed.
3. MOUNTAIN BIKERS CAN DO IT, TOO
If motorcycles can reap the benefits of mixed-wheel sizes, why not mountain bikes? With a 29-inch wheel, the benefit is more contact area between the tire’s tread and the trail, resulting in better traction. With the 27.5-inch wheel, the bike is more responsive in corners and the wheel is lighter. Sounds like a good mash-up, but does it work?
4. IF RACERS ARE DOING IT, SHOULD WE?
We always pay close attention to innovations that the pros are having success with. We have heard reports that the mixed-wheel size is reducing the number of crashes. Matched-wheel enduro bikes handle well at moderate speed, and downhill bikes handle great at high speeds. Riders feel mixed setups can provide some benefits at both speeds. With “Super Bruni” dominating World Cup runs on his mixed-wheel machine and Danny Hart pedaling his mixed-wheel bike to a win at Snowshoe, West Virginia, don’t lie and say you’re not just a little bit curious about what a mixed-wheel bike could do for you. The evidence that pedaling a mixed-wheel machine will promote speed is mounting. We’ll keep an eye on the results of this experiment and update you as we find out more.
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