Bike Sizing Guide

Getting the right bike at the right size for you or a loved one is a really important decision. Being comfortable on a bike and maximising your riding experience is as much about fitting the bike to your size as it is about cost or style. Just because a bike feels good and looks good, doesn't mean that you are maintaining the correct posture or using the right size of bike to get the most out of your bike.

At Ridelow, we employ bike experts...hardened, race weary souls who have endured all that the roads and mountains and trails of the UK and Europe have to offer.....and they know their bikes. They are always on hand to give advice over the phone or online via email, so please use our unrivalled services if you are an existing customer, a prospective customer or you just need some good old fashioned advice about whether you could get more out of your bike.

Bike sizes are determined by the frame size, based on the length of the seat tube. Most manufacturers measure from the centre of the crank axle (bottom bracket) to the top of the seat tube, where the seat post is inserted.

Some manufacturers measure their models from the intersection of the top tube and seat post to the crank axle, which can throw out some of the sizings, so if ever in doubt call one of our experts on 0161 834 5578 for the very best advice and guidance.

Manufacturers quote sizes in different ways, some quote the size in centimetres, some in inches and some as a frame size (such as Small, Medium, Large, etc). Although the size of frames are based on the measurement of the seat tube, it is not just the seat tube that changes depending on the size – the entire frame changes in proportion to the frame size.

The best way to choose the right size bike for you is to first of all measure your height. This sounds simple but we suggest you stand against a wall with your shoes off. Keep your legs together and your shoulders back. Carefully place a pencil on top of your head and mark the wall – for best results get a helper to mark the wall for you. Then measure the mark on the wall with a tape measure from the ground up. If your height is on the cusp of the range your reach is often the deciding factor in which size to go for. To find out if you have a short or long reach measure your Ape Index (your arm span minus your height) – if you have a positive ape index then go for the larger size, if you have a negative ape index go for the smaller size.

You should also consider stand over height which is defined as the clearance between the top of the top tube (also known as a cross bar) and the bottom of your crotch. It’s important that you have adequate clearance in this area to avoid contact when you’re stopped and astride the bike. For road and hybrid bikes 1 to 2 inches of clearance is required, mountain bikes require 2 to 4 inches.

The sizes we recommend in our sizing charts take stand over height into consideration. So if you’ve got a close to average inside leg measurement our recommendations will be fine. If you have a short or long inside leg measurement in relation to your height we would strongly recommend discussing your requirements with us instore at Ridelow or over the phone on 0161 834 5578.

It is important to note that different types of bikes are sized in different ways. A 58cm road bike will be quite a different size to a 58cm time trial bike. Road, triathlon and time-trial bikes are the most important to size correctly. The reach can determine feel and the frame size required, stand over height is not as important.

The type or style of riding applicable to you will also affect which size you need. For example a mountain biker that wants to ride more aggressively and would like a more manoeuvrable bike may prefer a size smaller than they would normally take. Likewise a cross country racer that is looking for a flatter and speedier mountain bike may prefer a size larger than they would normally take. Basically there is no right or wrong when it comes to size – choosing the right bike comes down to personal preference and what you feel is comfortable and right for the rider you are.

Our sizing charts will provide accurate advice for the majority of cyclists, but for the best sizing advice we can not emphasize enough how a visit to our store at Ridelow or calling one of our experts is just as important as price or style.

Mountain Bike Sizing Guide (for hardtail and full suspension bikes)

Rider Height		Suggested Frame Size
Feet and Inches	Centimetres	Inches	Size
4' 10" - 5' 2"	148 - 158	13 - 14	XS
5' 2" - 5' 6"	158 - 168	15 - 16	S
5' 6" - 5' 10"	168 - 178	17 - 18	M
5' 10" - 6' 1"	178 - 185	19 - 20	L
6' 1" - 6' 4"	185 - 193	21 - 22	XL
6' 4" - 6' 6"	193 - 198	23 - 24	XXL

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Women's Mountain Bike Sizing Guide (for hardtail and full suspension bikes)

Road Bike Sizing Guide

Women's Road Bike Sizing Guide

Hybrid Bikes Sizing Guide

Trial/Racing Bikes Sizing Guide