How do I choose an MTB wheel?
There are many different sizes of MTB wheels and it is important to get the right one to fit your bike. There are five things that you need to consider when choosing a new wheel; wheel diameter, axle type, hub spacing, rim width and freehub type (rear wheel only).
What are the different wheel diameters (sizes)?
MTB wheels are available in 4 different diameters:
- 29” - cross country (XC) and trail bikes
- 650b (27.5”) – Most common size, XC, trail and downhill bikes
- 26” – the traditional wheel size, but is now less common
- 24” – only found on certain jump and junior bikes
What are the different axle types?
There are different axle types for front and rear wheels:
- QR (9mm) – quick release skewer – for front and rear wheels
- 10mm – thru axle - for rear wheels
- 12mm – thru axle – for rear wheels
- 15mm – thru axle – for front wheels
- 20mm – thru axle – for front wheels
What about hub spacing?
As with axle types there are specific hub spacing’s for front and rear wheels:
- 100mm - front, traditional size
- 110mm – front, Boost standard
- 135mm – rear, traditional size
- 142mm – rear, most common
- 148mm – rear, Boost standard
- 150mm – rear, Downhill bikes
Why does rim width matter?
Yes. This is because weight on the rim adversely affects acceleration and climbing more than weight on any other part of the bike. Having said that a wider (and heavier) rim is more robust and will offer more support for the tyre. For this reason, cross country MTBs tend to have narrower rims than trail and downhill bikes. As long as you get the wheel diameter, axle type and hub spacing to match your existing wheel it is usually possible to change the rim width for either a lighter or a sturdier wheel.
What about Plus sizes?
Plus sized 27.5” & 29” wheels use very wide rims (38-50mm) that require Boost standard hub spacing. You can only use these rims on ‘Plus Sized’ bikes.
What are the different freehub options?
The freehub is the part of the rear wheel that the cassette fixes on to. There are 3 main freehub types that fit specific cassettes:
- Shimano and SRAM– fits Shimano and SRAM 8, 9 & 10 speed cassettes
- SRAM XD – fits SRAM 11 & 12 speed cassettes
- Hope – fits hope 11 speed cassettes
If you match the above criteria, then you can be sure that the wheel you buy will be compatible with your mountain bike.
Do I need a disc specific wheel?
If you have disc brakes on your bike then you will need a disc specific wheel. There are two different types of disc rotors that are compatible with different hubs:
- 6 bolt – most common type
- Centre lock – used on certain Shimano hubs
Note – disc specific wheels are not compatible with rim brakes.
What about tubeless?
Some wheels are ready to be used with tubeless tyres straight out of the box while others can be converted with a simple conversion kit. This will usually be specified in the product description.
Wheels and Wheelsets
Wheels are either sold individually or in pairs known as wheelsets. Check the product description for more details.
If you are unsure about which wheel you need then please contact us by phone on 01792 799508 or email info@tredz.co.uk and we will be happy to help.
