Tue. Jun 18th, 2024
Mountain bike size chart

The most important thing when shopping for a new mountain bike or upgrading your current ride is determining the right size. A bike that is comfortable, responsive, and safe to ride is what you want.
You want your rides safe, fun, and fast.


Mountain Bike Size Chart


You’ll notice that our mountain bikes are listed in either an inch or a variety of sizes. Mountain bike frames are available in extra small (XS), medium (M), large(L), extra-large (XL), and extra-extra–large (XXL). These sizes will suit all types of riders.

Height (Centimetres & Feet)Inside LegMountain Bike Frame Size (CM)
152cm / 5′.0″71cm / 28″15″ (X Small)
160cm / 5′.3″75cm / 29.5″16″ (Small)
170cm / 5′.7″79cm / 31″17″ (Medium)
175cm / 5′.9″83cm / 32.5″18″ (Medium)
180cm / 5′.11″85cm / 33.5″19″ (Large)
188cm / 6′.2″89cm / 35″20″ (Large)
196cm / 6′.5″93cm / 36.5″21″ (X Large)


This MTB size guide will give you an idea of the size that would work best for you. Your height is the only dimension you will need.
This mountain bike size chart will help you to narrow down your search. You have many other things to consider when choosing the right bike. Let’s get into the details.


Types of Mountain Bikes


Our electric mountain bike buyer’s guides will help you find the right bike for you. These guides are packed with all the essential information you will need.
Modern mountain bikes have suspension at their front. Many also have suspension at their rear. Hardtails have front suspension only, while full suspension bikes are equipped with both rear and front suspension.
The front and rear suspensions work together to eliminate bumps and lumps. The suspension absorbs shock when you push over obstacles.


Your riding style will determine the size of your mountain bike and whether you choose a hardtail or full suspension model. The frame size will be affected by how you ride your bike, and where you ride it. Full-suspension bikes are preferred by downhillers for rolling over obstacles. XC riders may prefer smaller frames that can be handled faster over, under, and around obstacles.
This is a quick overview of some of the various types of mountain biking.

  • Cross-Country, or XC – XC could be anything from a gravel ride through to a run at your local trails center (and everything between). Full-suspension or hardtail? You decide.
  • All-Mountain: All-Mountain means riding on mountains. This type of riding involves a lot of climbing and tricky technical sections. We recommend that you have a full-Susser.
  • Trail riding – Trail bikes were designed to handle the varied terrain found at UK’s trail centers. Either a full suspension or hardtail bike is possible.
  • Downhill – Downhill bikes were designed to go downhill fast. Here, full suspension is preferable.
  • Enduro – Enduro bikes can be used to climb mountains and return down them. You can do anything.

A cross-country or trail bike is the best choice for someone who is new to mountain biking. These bikes are designed to handle trails and off-road riding and can be used on gravel or roads. Halfords stocks a variety of affordable XC bicycles.
We also have a selection of electric mountain bikes (EMTBs),. These machines have the potential to change what is possible on the trails. They’re full of tech but they are as familiar with the frame sizes and components as their pedal-powered counterparts.


Mountain Biking Measurements


Safety is the most important aspect of choosing the right size mountain bike. Safety is key. You must be able to control your bike and steer it safely. These are the basics of mountain biking:

  • When you stand over your frame, with your feet on the ground, there should be approximately 2 inches of space (approximately 5.5cm) of air. This is only a guideline and may not be applicable to all riding styles such as downhill.
  • Comfortable pedaling should include a slight bend at the knee at each stroke’s end.
  • You don’t want your bike to feel strained or cramped. You want to feel relaxed and comfortable, ready to spend hours in the saddle.
  • Both brake levers must be reachable and operated by you.

Mountain bike sizes are determined by the length of your seat tube. Your old bike is the best place to start. Measure the length of the seat tube on your bike from BB to clamp and then buy the same size frame.
You don’t need a mountain bike? Then it’s time for a tape measure. You can determine the size of your frame by measuring your inseam. This is how it works:
Your ideal frame size is a measurement of your inseam x 0.67 – 5. inches
This method is more sophisticated than simply using your height. It provides a more scientific and reliable approach to mountain bike size. Although it’s not perfect, it can help narrow down your choices.


How to Measure a Mountain Bike Frame


Mountain bikes are usually measured by the length of the seat tube. But, it’s not enough to have a bike that fits like a glove. Professional bike fitters will consider all of these dimensions when determining the right frame for you. Although you may not need or want a professional bike fitter, it is helpful to know some of the terms that are used.
Here’s how to measure your mountain bike frame if you have a tape measure.

  • The length of the seat tube (not including saddle and seat post) is the distance between the bottom bracket (crank), and the top end of the seat tube.
  • Size of the wheel – The size of the wheels. Usually 27.5″ or 29″ but older bikes may have 26″ wheels.
  • The effective length of the top tube – This is the distance from the top of the head tube to the center line of the seat post.
  • Reach – The distance from the center of the headtube to a vertical line drawn from the bottom bracket is called the reach. This is a better indicator of reach than the effective length of the top tube.
  • Head angle – The angle between the head tube’s angle and the ground is called the head angle. A shorter head angle can make a bike more responsive and agile on trails but it can also cause jitteriness downhill and at speed.

Other factors, like the seat angle and length of the chainstay, can also affect how a bike rides and performs. However, they are less important when choosing a size frame that fits. For buying the best mountain bike go to this link – https://o.bike/best-mountain-bikes-under-300/


Size Up or Down for Your Mountain Bike


It may be difficult to choose between a bigger or smaller mountain bike frame. How do you choose the right size mountain bike frame?
The size of your mountain bike depends on your reach. Depending on your sitting height or trunk length, your upper body length will affect your reach. Your Ape index can help you narrow down your search. The Ape index measures how wide your arm span is relative to your height.


For your Ape index, extend your arms out and ask someone to measure the distance between your two longest fingers. Add that to your height. If your arm span exceeds your height, it means you have a longer reach. We recommend the larger frame. We recommend the smaller frame if your arm span is less than your height. Although numbers can help narrow down your search, they are not always definitive. Some riders prefer a bigger frame than others. This is how to size up or down.


What You Get For Sizing Up


A longer wheelbase is the distance between two wheels on a mountain bike frame. You’ll be able to bounce off obstacles rather than flipping or whipping around them.

Many riders prefer smaller mountain bike frames because they are easier to maneuver and more efficient. A shorter wheelbase makes it easier to maneuver around obstacles. It will be slightly lighter than the larger frames. It will have a more upright riding position. We recommend a smaller frame if you are looking to install a dropper seat post.


How Do I Set My Bike up for My Riding Style?


The first step in finding the right size mountain bike is to find the perfect fit.
You may need to adjust your mountain bike so that you are in a more upright riding position. Adjust your saddle by using a multi-tool or hex key to adjust it to a 30-degree angle from your hip, knee, or ankle. This will make your ride more comfortable, especially if you are riding for a longer time.


Want to increase your speed? You can make your riding more aggressive by tilting your seat forward. This will allow you to pedal a bit more.
There are many aftermarket parts and upgrades available that will help you personalize and improve your bike beyond minor adjustments. Halfords has a wide range of amazing accessories and upgrades, so whether you are looking for new pedals, a larger wheelset, or a different-sized stem, you will find it all at Halfords.
Demoing Mountain Bikes


It’s more than numbers. It’s about getting the right feel. Although we know that it is not always possible for you to visit a Halfords shop, you will be able to see, try-ride, and sit on a selection of the UK’s top mountain bikes from brands like Voodoo, Boardman, and Carrera.


One of our certified technicians can help you if you visit any Halfords shop. Advice and information on how to get the perfect mountain bike fit. They will be able to explain the differences and help you find the right bike for you.


MTB Sizing – Commonly Asked Questions

These are quick answers to some of the most common questions about MTB sizing.


What is the Size of Mountain Bikes?


Mountain bike sizes are measured in inches. However, you will see the frames listed by their size (extra small to medium to large, medium to large, large to extra-large, extra-large, extra-extra-large, and extra-extra–large). The Halfords Mountain Bike Size Reference allows you to use your height to determine the right size mountain bike frame for you.


What MTB size is the Best?


Mountain bikes can come with either 27.5″ (650b), or 29″ wheels. Each has its advantages and disadvantages. Older mountain bikes had 26″ wheels. We won’t go into too much detail, but bikes with 27.5″ tires can be more responsive and maneuverable. Bikes with larger 29-inch wheels will roll better and offer greater stability. The decision is up to you. We recommend that you test before buying.


What Size Mountain Bike Should I Get?


A mountain bike that is the right size is comfortable to ride, easy to control, and most importantly, safe. You are all different, but you can easily determine if you need a medium or large mountain bike.
Do you need more assistance in choosing the right mountain bike?


The tallest mountain in the world You can talk to one of our experts if you need help finding the right mountain bike frame for you. We will be happy to help you choose the right size frame and provide guidance on personalizing it to make your ride even more enjoyable. We can even build it.