Mixed-wheel bikes, mullet bikes, Franken-bikes…call them what you want, but riding different-size wheels on a mountain bike has been a hot topic in 2019. Maybe it’s because the UCI finally “legalized” them for competition, or maybe it’s the fact that when used in competition, riders actually won races on mixed wheel mountain bikes. Regardless, the trend to run a 29-inch front and 27.5 rear wheel combination is here to stay. And with features like quicker handling, faster acceleration, and the combined benefits of a 29er and a 27.5 wheel, it makes sense for serious enduro riders to be eyeing a mixed-wheel bike to add to their collection. Here are 5 reasons you might find yourself riding a mixed-wheel bike in 2021.