While 26 inches is considered the “standard” wheel size in the mountain bike industry, 29-inch wheels are fast on their heels. Recently, another wheel size has been garnering a lot of attention. Referred to as 650B, the 27.5-inch wheel fits right in between the 26- and 29-inch offerings.
With so many wheel sizes, you might be wondering which one is best for you. You're not alone. Read on to learn a bit more about each option, and why it may—or may not—suit your needs.
Long considered the standard wheel size in the mountain bike industry, 26 inches is likely the size of the wheels you have on your mountain bike, unless you actively sought out something different.
The advantages: 26-inch wheels offer unmatched maneuverability. Why? Because virtually all advancements in mountain bike geometry and technology have been modeled off of 26-inch wheels. It’s true, the 26-inch-wheel bike has been evolving for many, many years and because of that, its front-center/rear-center balance is ideal. Unfortunately, you can’t just change the wheel size and expect the established 26-inch standards to work. Therefore, 29-inch-wheel bikes still have some developing to shorten the chainstay in order to obtain optimal handling.
The disadvantages: It’s been said that the existing 26-inch wheel size may have been chosen a bit arbitrarily. In fact, the 26-inch standard was created before mountain bikes came into the picture. There’s a reason larger wheel sizes are gaining traction, and that’s because they might be better suited for some riders. Research your options and go for a ride on a couple different sized wheels before you commit to one.
Gaining major momentum, 29-inch-wheels are expected to become the prevailing wheel size for most mountain bikes with five inches of travel or less.
The advantages: Bikes with 29-inch wheels—commonly called “29ers”—can ride over anything. OK, maybe not everything, but it sure feels like it! I’ve marveled in disbelief after riding over logs and other obstacles that slow me down or stop me in my tracks on my 26-inch steed. Wondering how? The obstacle hits the rim of the 29er at a lower point, making it easier to roll up and over. Other advantages include maintained momentum, reduced rolling resistance and increased stability from a longer wheelbase.
The disadvantages: Regrettably, that longer wheelbase also reduces the bike’s maneuverability. As mentioned before, 29er chainstays need to be longer in order to fit a larger wheel on the frame. Longer chainstays result in not-so-ideal handling. Other shortcomings consist of a somewhat heavier wheel mass and slower acceleration from a complete stop.
Around, but ignored, for a long while, the middle child of 26- and 29-inch mountain bike wheels has people talking these days. As a wider selection of 650B-specific components become available, the mountain biking industry—and the mountain bikers themselves—are taking notice.
The advantages: Advocates of 27.5-inch wheels—typically called 650B—state that they offer the same roll-over qualities as 29ers, without compromising maneuverability. They also allow shorter riders who might not feel comfortable on 29-inch wheels the chance to experience a bigger sized wheel. What’s more, you can have longer travel than a 29er without compromising geometry.
The disadvantages: At the moment, there is a limited selection of tires, wheels and forks to pick from. In addition, some industry insiders don’t see 650B as a big enough performance benefit over 29-inch wheels to justify their rise in popularity.
So, what tire is best for you: 26-inch, 650B or 29-inch? To answer that question, you must take into consideration who you are as a rider, what terrain you most often frequent and what you want out of your bike.