by Mike Finlay

Created on: May 28, 2008

There is a massive array of mountain bikes on the market at the moment, ranging from the basic budget rigid frames right the way through to the full suspension downhill animals produced by the likes of Santa Cruz. Each frame seems to vary in design and there seems an endless spectrum of wheel size. But DON'T PANIC!

The basic guidelines for sizing up your bike have not changed with the advances in styles. Your first choice is to decide what you want the bike to accomplish, by which I mean; are you wanting to tear down rocky downhill trails or pedal for hours over stunning countryside? Secondly, once you've decided upon the answer to question one, you need to look into a range of frames and brands that will suit these needs. This is obviously important as it is based entirely upon how much you would like to spend (see guides in this section on 'all-mountain bikes').

Finally, now you have a picture of your desired bike in your head, it's time to go out and spend the hard earned cash. The final question that needs answering soon will be; what size bike will suit me?

The most simple way of finding the answer to this question is to go and try out the bike of your dreams at one of the brand's suppliers. Test one or two different sizes and use some advice from the shop staff, who are generally bike enthusiasts themselves. The rule of thumb is to throw one leg over the bike and stand flat footed over the top tube of the frame. This should leave around a two inch gap between the frame and your intimate bits! The obvious reason for this is that stopping at lights will prove pretty difficult (not to mention painful!) if you can't do this.

If, on the other hand, your only option is to order the bike and you need to know more about the actual sizing charts, read on...

The frameset is measured from the center of the bottom bracket (where the chain ring joins the frame) to the top of the seat tube. Unfortunately, in the same way that shoe sizes vary from brand to brand, so do frame sizes. This returns us to the better choice of trying before you buy. However, as a rough guide you'll need to measure the length of your inside leg and check it on the scale below (this is for mountain bikes):

LEG SIZE (cm) WHEEL SIZE (inches) FRAME SIZE (cm)

52-66 20 33
60-74 24 38
65-76 26 41
66-79 26 43
69-81 26 46
71-84 26 48
74-86 26 51
81-94 26 56

The leg size should be measured from your crotch to the floor and then choose the frame size in which your measurement fits around the middle of the 'leg size' scale. Any further adjustments to tailor the bike to your exact size can then be made by adjusting the seat height.

Hopefully this has given you an insight into how to work out a frame to suit you, however there is no substitute for trying out the bike yourself to avoid disappointment.

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