General Size Guide
General Bike Size Guide
Choosing the right bike size makes a huge difference to comfort, control and efficiency. Use the guide below to find the ideal frame size for your height and inside leg measurement.
What You Need
Your Height
Stand with your back against a wall, shoes off, feet together. Mark the wall above your head with a pencil, then measure from the floor to the mark.
Your Inside Leg Length
Stand with your back against a wall, shoes off. Place a book or ruler between your legs (as if sitting on a saddle) and measure from the floor to the top of the book/ruler. Having someone assist makes this easier.
Remember: This guide provides general sizing only. Different brands may vary. If you’re unsure, speak to the Bike Shed team on 01363 774773 or send us a message — we’re always happy to help.
Mountain Bike Sizing (Men)
| Height |
Inside Leg |
Recommended Size |
| 147–152cm / 4'10"–5'0" | 66cm / 26" | 13” (X Small) |
| 152–160cm / 5'0"–5'3" | 69cm / 27" | 13”, 14” (X Small) |
| 160–170cm / 5'3"–5'7" | 71cm / 28" | 15”, 16" (Small) |
| 170–175cm / 5'7"–5'9" | 76cm / 30" | 17", 18” (Medium) |
| 175–180cm / 5'9"–5'11" | 79cm / 31" | 18”, 19" (Medium, Large) |
| 180–188cm / 5'11"–6'2" | 81cm / 32" | 19", 20” (Large) |
| 188–196cm / 6'2"–6'5" | 86cm / 34" | 20", 21”, 22” (Large, X Large) |
| 196cm+ / 6'5"+ | 91cm / 36" | 23", 24” (XX Large) |
Mountain Bike Sizing (Women)
| Height |
Inside Leg |
Recommended Size |
| 147–155cm / 4'10"–5'1" | 66cm / 26" | 13”, 14" (X Small) |
| 155–160cm / 5'1"–5'3" | 69cm / 27" | 13”, 14” (X Small) |
| 160–165cm / 5'3"–5'5" | 71cm / 28" | 15”, 16" (Small) |
| 165–172cm / 5'5"–5'8" | 76cm / 30" | 17", 18” (Medium) |
| 172cm+ / 5'8"+ | 79cm / 31" | 19" (Large) |
Road Bike Sizing (Men)
| Height |
Inside Leg |
Recommended Size |
| 147–152cm / 4'10"–5'0" | 66cm / 26" | 47–48cm (XX Small) |
| 152–160cm / 5'0"–5'3" | 69cm / 27" | 49–50cm (X Small) |
| 160–170cm / 5'3"–5'7" | 71cm / 28" | 51–53cm (Small) |
| 170–175cm / 5'7"–5'9" | 76cm / 30" | 54–55cm (Medium) |
| 175–180cm / 5'9"–5'11" | 79cm / 31" | 56–58cm (Large) |
| 180–188cm / 5'11"–6'2" | 81cm / 32" | 59–60cm (X Large) |
| 188–196cm / 6'2"–6'5" | 86cm / 34" | 60–62cm (X Large, XX Large) |
| 196cm+ / 6'5"+ | 91cm / 36" | 62–63cm (XX Large) |
Road Bike Sizing (Women)
| Height |
Inside Leg |
Recommended Size |
| 147–155cm / 4'10"–5'1" | 66cm / 26" | 44–46cm (XX Small) |
| 155–160cm / 5'1"–5'3" | 69cm / 27" | 47–49cm (X Small) |
| 160–165cm / 5'3"–5'5" | 71cm / 28" | 50–52cm (Small) |
| 165–172cm / 5'5"–5'8" | 76cm / 30" | 53–55cm (Medium) |
| 172cm+ / 5'8"+ | 79cm / 31" | 56–57cm (Large) |
Hybrid Bike Sizing (Men)
| Height |
Inside Leg |
Recommended Size |
| 147–152cm / 4'10"–5'0" | 66cm / 26" | 13”, 14" (X Small) |
| 152–160cm / 5'0"–5'3" | 69cm / 27" | 14”, 15” (X Small, Small) |
| 160–170cm / 5'3"–5'7" | 71cm / 28" | 15”, 16" (Small) |
| 170–175cm / 5'7"–5'9" | 76cm / 30" | 17", 18” (Medium) |
| 175–180cm / 5'9"–5'11" | 79cm / 31" | 19”, 20" (Large) |
| 180–188cm / 5'11"–6'2" | 81cm / 32" | 20", 21” (Large, X Large) |
| 188–196cm / 6'2"–6'5" | 86cm / 34" | 21”, 22” (Large, X Large) |
| 196cm+ / 6'5"+ | 91cm / 36" | 23", 24” (XX Large) |
Hybrid Bike Sizing (Women)
| Height |
Inside Leg |
Recommended Size |
| 147–155cm / 4'10"–5'1" | 66cm / 26" | 13”, 14" (X Small) |
| 155–160cm / 5'1"–5'3" | 69cm / 27" | 14”, 15” (X Small, Small) |
| 160–165cm / 5'3"–5'5" | 71cm / 28" | 15”, 16" (Small) |
| 165–172cm / 5'5"–5'8" | 76cm / 30" | 17", 18” (Medium) |
| 172cm+ / 5'8"+ | 79cm / 31" | 19" (Large) |
Trek Bikes SIze Guide
Trek Road Bikes
Madone, Emonda, Domane, Silque, Lexa, Boone, 1 Series
| Frame Size | Height cm | Height Ft |
| 50cm | 157-165cm | 5.2-5.5 |
| 52cm | 163-170cm | 5.3-5.6 |
| 54cm | 167-176cm | 5.6-5.9 |
| 56cm | 173-180cm | 5.8-5.11 |
| 58cm | 179-187cm | 5.10-6.2 |
| 60cm | 183-192cm | 6.1-6.3 |
| 62cm | 189-197cm | 6.2-6.5 |
| 64cm | 194-201cm | 6.4-6.7 |
Trek Mountain Bikes
Top Fuel, Procaliber, Superfly, X-Caliber, Cali, Remedy, Fuel EX, Stache, Farley, Slash, Marlin, Roscoe
| Frame Size | Height (cm) | Height (ft) |
| XS | 148-155cm | 4.10-5.1 |
| S | 153-163cm | 5.0-5.4 |
| M | 161-173cm | 5.2-5.8 |
| ML | 171-181cm | 5.7-5.11 |
| L | 177-189cm | 5.9-6.2 |
| XL | 187-197cm | 6.1-6.5 |
| XXL | 197-198cm | 6.5-6.6 |
All Trek mountain bikes use alpha sizing instead of numeric sizing. Rather than labelling our bikes with size numbers like 17.5 and 19.5, we use sizes like M (medium) and L (large).
Why alpha sizing?
1. It’s easier to understand
'Medium' is intuitive. '17.5' is not. Alpha sizing makes it easier for you to know what Trek mountain bike will work for you. A lot of other brands also use alpha sizing, and if you ride a medium in a different brand, you’ll probably ride a medium Trek as well.
2. Frame sizes are measured differently today
Trek frame size used to be measured by the length of the seat tube. But modern mountain bike geometry is based on reach, not seat tube length. Alpha sizing is simpler and helps you find the right fit by the measurement that matters most.
Sizing conversion
The new alpha sizing corresponds with the previous numeric sizing for all models:
| Alpha size
|
XS
|
S
|
M
|
ML
|
L
|
XL
|
XXL
|
| Frame size
|
13.5
|
15.5
|
17.5
|
18.5
|
19.5
|
21.5
|
23
|
| Rider height
|
147-155 cm
4’9”-5’1”
|
153-162 cm
5’2”-5’3.8
|
161-172 cm
5’3.4”-5’7.7”
|
170-179 cm
5’6.9”-5’10.5”
|
177-188 cm
5’9.7”-6’2”
|
186-196 cm
6’1.2”-6’5.2”
|
195-203 cm
6’4”-6’7.9”
|
Extended size range
Trek offers mountain bikes in a wide range of sizes to ensure the perfect fit for all riders. That includes an XS with increased standover height, an ML (medium-large) perfect for those in-betweeners in the middle of the sizing bell curve, and an XXL for taller riders who often struggle to find a bike that’s big enough.
Not all sizes are available on all models, but Trek’s extended size range will help any rider find a frame that fits better from the start and requires fewer changes to the cockpit.
Finding your Size
The easiest way to determine your frame size is by height, but many riders find that they are between sizes. Choosing to go up or down a size depends on your personal riding style and body proportions.
A bike with a longer reach will have a longer wheelbase. That makes it more stable, especially on high-speed descents. That’s great for riders who like to plough through rather than pop over rough stuff on the trail. If you have a relatively long torso or arms for your height, you may find that a longer reach gives you a roomier, more comfortable cockpit.
A bike with a shorter reach will have a shorter wheelbase. It’s not as stable, but it’s more nimble and easier to flick around. That’s great for riders with a more playful, active riding style who like to get off the ground and whip their wheels around. If you have a relatively short torso or arms for your height, you may find that a shorter reach makes it easier for you to hold the handlebars comfortably.
Effective top tube
Effective top tube is the horizontal distance from the centre of the head tube to the centre of the seat post. This measurement represents how a mountain bike fits while you’re sitting on the saddle. It’s important for cross country riders, who prioritise pedalling power.
Reach
Reach is the horizontal distance from the centre of the head tube to a vertical line that runs through the centre of the bottom bracket shell. This measurement represents how a mountain bike fits when you’re standing up on the pedals, like when you’re descending. Since most trail riders prioritise out-of-the-saddle riding, this tends to be the most helpful metric when comparing bike sizes from different brands.
