What MTB Wheel Size? Cycles UK Explain's
As the cycle industry introduces a third wheel size, it can be very confusing to know or to understand what is the right wheel size for you as a customer.
This brief guide below will help you to understand the industry standards for the 3 wheel sizes and the benefits that they have to you as a rider.
This is the original wheel for most bike manufacturer’s size and the world’s recognised international standard for MTB wheels.
The smaller diameter rims and shorter spokes means that 26in wheels can be made light and strong. This results in them being more responsive than other wheels sizes under acceleration but also more agile when riding off road.
Spares for 26” wheels are becoming more difficult to source than 29in and 650b (27.5") replacements due to the change in wheel size standards. This means you will have a restricted amount of options when it comes to upgrading your tyres and forks.
Advantages and Disadvantages of 26" Wheels
- They can be made lighter, stiffer and stronger than other wheel sizes.
- More agile handling than larger wheels.
- Becoming more difficult to source spares and replacements.
- Lose their rolling speed easier than larger wheels.
650b / 27.5in Wheel
With 29ers being introduced into the MTB industry, then to introduce a third wheel size was always going to be complicated. The 650B has been accepted with open arms and has been very successful so far and will become the new industry standard as they phase 26" wheels out over the next few years.
The first thing to realise is that the wheels aren't actually 27.5in but closer to 27in. As a result they’re significantly faster to accelerate and easier to manoeuvre than the larger 29er wheels on the trail. It has also been noted that there is less steering inertia and flex within the handling too. This results in the handling feeling more responsive and balanced. The wheels are still small enough to work with long travel suspension frames and forks without them feeling odd or looking strange. 650B tyres still roll over rough ground more smoothly and grip noticeably better than 26in equivalents, although not as well as 29in wheels.
Due to the new wheel size has been introduced so suddenly, most manufacturers were struggling to manufacture enough bits for complete bikes. This did result in spares being occasionally tricky to find if you were in a hurry, however this is no longer a problem.
Almost all manufacturers have followed suit in making 650B the standard wheel size for there bikes, making 26" almost obsolite.
Advantages and Disadvantages of 650B Wheels
- Faster accelerating, stronger, stiffer and more agile than 29er.
- Noticeably smoother than 26in.
- Handling and wheel placement feels a lot more natural than 29er wheels.
- Slower rolling than it's 29" counterpart.
This particular wheel size broke the stranglehold of the MTB wheel market, it produces a very different feel. This is due to 29in wheels being larger, they’re generally heavier and harder to get moving.
Their size and stability also means it’s taken a while for bike designers/manufacturers to make big wheeled bikes handle in a fun way. They’re still harder to manoeuvre on really tight, twisty or jump and pump trails compared to smaller wheels bikes. It’s also more difficult to manufacture big wheels and small frames or long travel suspension fit and work together. Also because of their lack of acceleration they’re not as quick to get going and their smoothness often dulls the sensation of speed and they feel much slower than they actually are. It has also been noted that sometimes some 29ers look awkward due to its size and it’s easy to see why 29ers took a while to catch on.
Once rolling, 29in wheels hit rocks and roots at a shallower radius angle and with more momentum they tend to roll over the top of rough terrain easier from the longer contact patch that the wheel creates. This means that any given tyre grips better or you can run slicker, speedier rubber without slipping. Add their natural extra stability and they’re perfect for powering straight through trouble.
There’s a full range of different styles of 29er bikes to choose from now too, so there is a bike for almost all disciplines.
Advantages and Disadvantages of 29" Wheels
- Smoother, more stable for better control on rough terrain.
- Slower to get moving and to accelerate, however they hold their speed and roll better once.
- Can feel awkward on tight slow trails and harder to sync with long travel suspension or small frames.
- A little more confidence inspiring for novice riders off road.