What MTB wheel sizes are best for your bike? The good old 26-inch wheel, the larger 29-inch wheel, or the in-between 27.5-inch wheel? This one is a never-ending debate with supporters of each of the three wheel-sizes sticking to their own guns.
Not so long ago, 26-inch wheels were the only MTB option. Riders from cross country to downhill were all using 26-inch wheels on their bikes. The reason? When mountain biking was started, the 26-inch wheel became the standard by accident and the size stuck.
However, there have been many debates between MTB designers in recent years whether this size is the ideal one, and the outcome was the new wheel sizes.
But 26-inch wheels shouldn’t be dismissed right away since they have many advantages over the remaining sizes. Having smaller diameter and shorter spokes, a 26-inch wheel will always be stronger than a 27.5-inch wheel or a 29-inch wheel, as well as the lightest.
However, due to their small size, 26-inch wheels tend to roll less smoothly over obstacles than the other two wheel-sizes.
Although they came after the 29-inch wheels, we’ll put the 27.5-inch wheels, also known as 650b, between the 26-ers and 29-ers because they promise to deliver the best of both 26-inch wheels and 29-inch wheels. In a very short period, they have become largely accepted by both the MTB industry and MTB riders.
When compared to the 26-inch design, 27.5-inch wheels hit obstacles at a shallower angle, so they tend to have a better rollover resistance, but not better than the 29ers. Compared with 29-ers, 27.5-inch wheels are lighter and stronger, with better acceleration and sharper handling.
Due to their larger circumference, 29-inch wheels hit obstacles at a milder angle than 26-inch wheels, so they have better rollover resistance. Another advantage of 29-ers is their longer contact patch which helps them to have a better grip than the 26-inch wheels.
However, many riders have reported that bikes with 29-inch wheels have a different feel to those with 26-inch wheels with the earlier designs feeling slow to turn and less nimble than 26-inch bikes. The extra weight of 29-inch wheels is considered another downside because they take more effort to accelerate.
The Best MTB Wheel Sizes?
It all comes down to the type of rider and the terrain that you want to ride.
The 26-inch wheels are still in use, especially in the downhill discipline. Downhill bikes use long-travel suspension and their wheels must be as tough as possible, so the 26-inch wheels are still the best option.
For the XC discipline, the 29-inch wheels are ideal since they are the fastest when less technical riding is in question.
But if general trail riding is your thing, then the new generation of 27.5-inch wheels should be your choice, since they combine strength, traction, and agility in one package.