Mountain Bike Sizing and Fit

Mountain Bike Sizing and Fit


In choosing a new bicycle, picking the right size frame is vital if you want to have the perfect position when riding. There are various other factors to consider but frame size is the most important and if you get this wrong, nothing else will matter.

 Mountain Bike Sizing and Fit Matters

There are many online charts that are designed to help cyclists in choosing the right frame so I will not reproduce one here. However, before you head off to look for one, make sure that you have your height and inside leg measurements on hand. As frames are usually measured from the centre of the crank to the top of the frame where the seat tube will be inserted, the most important measurement to consider when choosing a frame is your inside leg as this will dictate whether a certain model will be a good fit or not.


Once you have established what size frame you need, it is time to consider the other factors that will affect your riding position and whether you are likely to be comfortable over long distances. The four most important of these are listed below:


  1. Seat post height – To set this properly, it is best to ensure that your seat is parallel to the floor before starting. Mount your bike and rotate the cranks until one pedal is in the lowest position and the other is as high as it can go while making sure that the cranks are in line with the seat tube. The angle of your extended leg should be around 10-15 degrees; any more and you will probably need to raise the seat post, any less and it should be lowered.


  1. Stem length – Although the ideal length will depend, to a large extent, on the ratio of your leg to body measurements, personal preference comes into it as well. You may need to experiment a little before you find the ideal position so do not be afraid to try several different settings. Generally speaking, the longer the stem, the more your body will be angled forward and your back flattened. A shorter stem will result in a more upright riding position. The best position should involve a slight bend of the elbows when you are riding in a straight line, in order to avoid placing unnecessary strain on your wrists.


  1. Handle bar width – As this is not something that can be adjusted, you will need to choose the most suitable handlebars when you order your cycle. For those who regularly ride over rough terrain, wider bars can make it easier to steer. Due to the riding position that results from fitting wide bars, they can also facilitate deeper breathing when tackling demanding gradients. This makes it handy for those who live in mountainous areas or regularly take on the most challenging mountain bike routes that they can find.


  1. Handle bar height – The height of your bars, as well as the length of the stem, which was covered above, can affect the angle of your back when riding so it is important to make sure that you get it right. How much adjustment you have available will depend on the design of your bike but if you need more than is provided by using spacers on the steering tube to raise the height of the stem, you may need to think about investing in a riser bar.



Other factors to consider include handlebar grips, the length of your crank arms and the position of your pedals and saddle. By keeping the aforementioned points in mind, you should have no trouble in getting the perfect bicycle for your outdoor pursuits.


About the Author

ProBikeKit is a leading provider of bike tires, frames, and other components across the UK. They offer clients with a wide range of products, both online and offline.

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