A Guide to Cycle Frame Sizes

Just about every cyclist will have had some experience of riding a bike that just wasn’t the right size and which, as a result, was uncomfortable. Riding an inappropriately sized bike can also be dangerous – so it’s something best avoided. Here is a quick overview of some of the issues you will need to take into account when selecting the size of your bicycle frame.

The old days of Cycle Frames

If you are much above a certain age, you might remember the days when bikes were measured primarily based upon the size of their wheels.

Today, a greater degree of precision and science is involved and that includes a number of metrics:

• Your own height and to some extent build. For example, you can be relatively tall but have moderately short legs. The reverse is equally true;
• The frame size. This is typically measured from the centre of the crank axle to the top of the tube seat but just to make things a little more complicated, not all manufacturers use the same measure. Some may simply describe it as small, medium or large frame or even measure from the crank to the crossbar;
• The stand height. That is normally the distance from the top of the crossbar to your crotch. If that’s sounds slightly odd, it actually has a very practical purpose – that of trying to make sure that some of your delicate regions won’t come into contact with the crossbar if you hop off of the saddle when at a traffic light etc;
• The type of bike you’re choosing. The characteristics of touring bikes, trail bikes and sport performance machines plus all the other varieties of modern bicycle around are all very different to each other. To some extent this is a question of simply understanding the feel of a given frame and how it looks against the body of an individual cyclist.

Using the metrics

Choosing a bike with an appropriately sized frame isn’t something that necessarily can be done by simply keying some of the above figures into a calculator and getting out the magical answer.

To a very large extent, judgement and experience are critically important – just as they might be in getting an expert to help you if you had to select a suit or have one made for you.

Most professional bicycle retailers will have qualified staff on hand who will be able to take some of the above measures and then to start to think about an appropriate frame and indeed overall bike size for you.

Important as all the above science is when selecting a bicycle, it’s equally important that you feel comfortable on the bike you are considering purchasing and using.

This is far more than simply about the business of selecting a comfortable saddle – critical as that may prove to be! This is about the overall geometric relationship of the bike’s frame and wheels to the proportions of your body. For example, your seating position and angle may be quite different depending on the type of bike you select and the way you plan to ride it.

Ultimately there is little alternative but to take yourself along to a reputable specialist shop and put yourself in their hands.

Remember that the little extra time spent selecting a bike frame that is suitable for you will yield results both in terms of your comfort, safety and cycling performance.