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Hardtail mountain bike on trail

Mountain Bike Size Guide

Choose the right size MTB bike with our bike size guide. A good MTB fit will be more comfortable and easier to handle, as well as enabling you to ride more efficiently.

What size bike do I need?

Below you'll find our typical bike sizing chart. Click on the frame size you want to see the bike models that are right for you.

Height (feet & inches)

Height (cm)

Frame Size (inches)

Frame Size (cm)

General Sizing

4’8” – 5’1”

143 – 155cm

13"

44cm

XXS

5’1” – 5’4”

155 – 163cm

15"

48cm

XS

5’4” – 5’7”

163 – 170cm

16”

51cm

S

5’7” – 5’10”

170 – 178cm

18”

54cm

M

5’10” – 6’0”

178 – 183cm

19”

56cm

L

6’0” – 6’3”

183 – 191cm

20”

58cm

XL

6’3” – 6’5”

191 – 196cm

21"

60cm

XXL

6’5” – 6’9”

196 – 205cm

22"

62cm

XXXL


What size MTB should I choose if I am between sizes?

Sometimes our bike sizing calculator will recommend two different sizing options. This means that both the larger and smaller sizes recommended will both be suitable. It is a personal choice which size to go for, but most mountain bikers tend to opt for the larger size. So you don’t feel too stretched, you can (depending on the model) fit a shorter stem to improve the fit of a larger bike without adversely affecting the handling. This is the opposite to a road bike where it is better to lengthen the stem rather than shorten it.

For model specific sizing please check the product page.

Kona Mountain Bike front end

How are mountain bikes sized?

Mountain bikes are either sized in inches or with a general size like small or medium. MTB's are sized by the frame and this is traditionally based on the length of the seat tube, measured from the centre of the front chain ring to the top of the seat tube. 

However, mountain bike frames don’t always follow a classical design so the measurement may be based on a virtual seat tube measurement. Sizes do vary slightly between manufacturers.

Measuring MTB for sizing

Does wheel size make a difference

Predominantly there are three wheel sizes used on mountain bikes; 26", 27.5" and 29" but some others do exist like 27.5+ and becoming more prevalent 'Mullet MTBs' (27.5″ rear & 29″ front).

The size of wheel you pick will alter your riding position & riding style - checkout below which wheel size will suit you best.

26" wheels

26 inch MTB wheel size

This is the traditional mountain bike wheel size but most MTBs now feature larger wheels. 26” wheels are still a good option for junior riders and smaller adults who will find them more manageable than larger hoops. Most dirt jump MTBs still roll on 26” wheels.



27.5" (650b) wheels

27.5 inch or 650b MTB wheel size

This is now the most common wheel size on all mountain bikes from trail bikes to downhill steeds. 27.5” wheels offer the ideal balance between the nimble handling characteristics and rapid rolling performance. Some manufacturers offer 27.5” wheels on smaller sized models with 29” wheels for the larger frame sizes.



27.5"+ (6Fattie) wheels

27.5 inch or 6Fattie MTB wheel size

With 2.8” and 3.0” tyres on a 27.5” rim these tyres have a similar overall diameter to 29” wheels and are often compatible with 29er MTBs that feature BOOST axle spacing on the fork and back wheel. Offering more grip and more float (cushioning) this wheel size is ideal for hardtails although the extra weight will make them slower to accelerate.



29" wheels

29 inch MTB wheel size

29ers are becoming increasingly popular, especially with cross country, enduro and downhill racers. While slower to accelerate, these larger hoops carry speed much better over rough terrain so tend to be faster and offer more grip due to the larger contact patch of the tyre on the ground. They are less nimble than 27.5” wheels and some smaller riders will find them a bit of a handful in technical terrain.