The Bike List

What size wheels are best for the kind of mountain biking I do?

Mountain bikes are now available in more wheel sizes than ever before. Traditionally mountain bikes were only available with 26" wheels but over the last few years 29" wheels have become more popular. More recently than that, bikes with 27.5 "(650b) wheels are starting to appear and some manufacturers are even replacing the older 26" sized wheeled bikes in their ranges with the new 27.5" wheels altogether.

To help you understand the different characteristics of each of the three main wheel sizes we've put together some short summaries below.



26" wheels (559mm diameter)

The original size mountain bike wheel is now the smallest size you'll find on mountain bikes with the exception of a few dirt jump bikes that use 24" wheels.

Smaller 26" wheels are easier to manoeuvre and are ideal for those that like an active and nimble ride. The majority of Downhill / Freeride and Park / Street bikes use 26" wheels to allow riders to move the bike around quickly and easily making 26" the most playful wheel size.

A large number of all-purpose mountain bikes are still available with 26" wheels and probably will be for some time to come as many of those used to how their 26" wheeled bikes handle may continue to be happy with what they've always ridden.


650b / 27.5" wheels (584mm diameter)

The newest of all the three main sizes is the 27.5" wheel which is a kind of halfway option that offers benefits of both 26" and 29" wheels. Although often referred to as 27.5", the 650b wheel size is slightly misleading as it isn't actually 27.5" in diameter. It is in fact closer to being a 26" wheel than it is to being a 29" wheel which means 27.5" / 650b wheels ride more like a 26" wheel, but with a little more stability and speed.


29" wheels (622mm diameter)

29" wheels have really only gained traction in the UK in the last 2 to 3 years and are the largest wheels you'll find on a mountain bike.

Bigger wheels carry more momentum and a decreased angle of attack so they roll over obstacles and rough ground more easily and allow you to maintain your speed round corners. As more of the tyre is in contact with the ground a 29" wheel improves traction for better climbing, cornering and all-round stability. Your centre of gravity is also lower which results in a more stable feeling as you sit deeper in the cockpit. 29" wheels are ideal for use on open trails where you're more likely to want to roll over obstacles than jump them. 29" wheels are most commonly found on the latest Cross Country Bikes and all-purpose Mountain Bikes.


Is bigger always better?

Not always. It very much depends on what type of riding you do as to what wheel size is best for you. When picking the right wheel size try and consider what type of riding you're likely to be doing most of the time.

In simple terms smaller wheels are more nimble and therefore better suited to tight, twisting trails. Larger wheels tend to be better suited to more open trails and the increased wheel size will also give you extra confidence through rough technical sections. It's worth noting though that bigger wheels tend to weigh a bit more, so they will typically accelerate slightly slower than smaller ones.