Road Bike Sizing Guide

First and foremost – Be comfortable

Even the sizing systems in bike shops can get it wrong. If you don’t feel comfortable, you definately won’t in a few weeks, months, years time. Getting the fitting of a road bike takes time and tweaking, so don’t expect to get it right first time. Over time you will also change the way you want to ride, so you will be tweaking a number of the points we make below.

Ask yourself – What kind of biking are you going to do?

If you are going to get into racing then your road bars will need to be lower than you saddle to get you in an aerodynamic race position.

Touring or beginners will want to have the handlebar higher, as this will allow you to get used to the riding postion and not put too much strain on your back or neck.

When you first get on the bike you should have about an inch of clearance between the frame and between your legs. This means that it is the right size frame for you.

Road bike sizing chart

The road bike fitting proccess

Equipment needed:

Turbo trainer
Road bike
Plumb line

Step 1 – Adjust the saddle height

Get the crank arms in line with the seat tube, so one leg is fully extended. That leg should have a slight bend in the knee up to 20 degrees. Do NOT have you leg fully extended as this will do you an injury.

Fitting Tips – Make sure your hips dont rock when you rid or you will do yourself and injury over time. Make small adjustments to find the perfect position.

Step 2 – Adjust the position of the seat on the seatpost

Bring the crankarms up to the horizontal position, so both legs are at the same height.

Drop a plumb line from the front facing leg from the knee. It should exactly drop in the centre of the pedal, this gives the rider the best efficiency when riding.

If it falls in front of the pedal axel you will need to move the saddle back and vice versus if it is behind the axel.

Step 3 – Horizontal body position

Sit on saddle and place your hands on brake hoods.

The rider should then look down at the front wheel hub. The handlebar should obscure the hub, if the hub is in front of the handlebar you are going to need a slightly shorter stem and vice versus if it is behind the handle bar.

This process is designed to put your back at about a 45 degree angle.

Road bike fitting tips

Handlebar width – should be in line with your shoulders. Thinner handlebars give you a more aerodynamic position and wider helps open the diaphram for deeper breathing.

Crankarm length – if your legs are in proportion with your height then the following applies:

<5.5″          165mm crank length
5.6″-5.9″    170mm crank length
5.10″-6″     172.5mm crank length
>6.1″           175mm crank length

Saddle angle – many cyclists like to position the saddle slightly up or down. Start flat and then play about with the position to see what works for you.

Cleat position – this is arguably as important as fitting your bicycle. The centre of the cleat should be directly under the centre of the ball of your foot, this gives maximum power and efficiency.


Remember this is a guide and over time you need to tweak all these elements to see what works for you. If you end up with slightly wider handlebars and a seat that is angled upwards then as long as your comfortable, make it happen.

Road bike sizing videos

VN:F [1.9.22_1171]
Rating: 0 (from 0 votes)