How To Choose The Correct Size Of Bike For You?


Standing over the bike and having clearance is a rough but good indicator of the correct size bike

Inside leg measurement is standing bare feet 6 inches apart measure in a straight line right up to your crutch multiple

this by 107>107.5% and this is the length from crank to the position you sit on the saddle.
Saddle height is a matter of personal choice.
Stand over bike height is the clearance between your crutch and the top tube.

Correct inside leg measurement plus 1 inch road and 2 inch for a mountain bike for stand over height.
Please remember that bike frames usually increase in size by 2 cm so if in doubt go for a slightly smaller size. Smaller

bikes will be lighter and stiffer and more responsive.
If competing in triathlons then consider at least 2 inch as stand over gap.

Using your inside leg measurement is simply only a guide to choosing the right size bike frame for you.
Flexibility or tightness in one leg or back will help you decide which size frame to use.
Rider type do you spin or push gears and geometry of frame are all important factors.
Even the material the frame is made of Steel Carbon Titanium Ali all has different strengths and weaknesses. Some riders prefer a combination ali frame carbon forkes etc.

The 2nd most important thing is length from tip of saddle to handlebars
Place elbow on tip of saddle and hands facing towards handlebars, your tips of fingers should just about touch handlebars.

If not you need a shorter stem.

For more detail click on

Every bike manufacturer is different and a frame can be measured from centre of bottom bracket (known as cc) to top of frame of centre of top tube.
Depending on size of tube this can be a difference of 1>3cm!

Frame size is determined on the length of the seat tube, from axle (bottom bracket) to top of the point where the seat post enters

Rider height is not accurate because 2 riders of the same height may different preparations one longer legs shorter body and their longer body longer reach and shorter legs. We are all individual.
Make sure your bike is the right size for you rather than making the bike fit you.

If a women & man of the same height stood next to each other the women have longer legs shorter bodies and men tend to have longer bodies and shorter legs.

Personal choice is based base don what the rider requires, a grandmother cycling 1 mile to the shops will want comfort while a triathlete who wants to cycle the route as fast as possible will want to be aerodynamic.
Correct saddle height will give the rider optiumn pedal stroke. The saddle needs to be high enough if your heels were placed on the pedals your leg should be straight.
If you back pedal with heals on the pedals you should be able to maintain pressure on the pedals, if you lose grip (not due to carbon cycle soles) then it is likely your saddle is too high. In this position when you cycle normally your muscles will be working more efficiently.

Having helped others for 17 years with correct bike fitting use my triathlon frame size if buying a bike for triathlons.
It is far too detailed why but if you need to discuss this with me in more detail while I check your bike fit.
Almost every rider has improved performance, all have reduced injuries or aches and pains with my bike fit.
Contact me now for a bike fit.

From my experience 6 out of 10 have a bike that is too big.

Other factors to take into consideration.
Top tube length
Height of tip of saddle to height of handlebars
Crank length

Bike aches and pains can be found on the following link

While I am loathed to give you the suggested size here is an approximate

Female riders height IronMate suggested bike frame size
Feet and Inches Centimetres Centimetres Approx
4' 10" - 5' 1" 147 - 155 44 - 45 - 46 XXS
5' 1" - 5' 3" 155 - 160 47 - 48 - 49 XS
5' 3" - 5' 5" 160 - 165 50 - 51 - 52 S
5' 5" - 5' 8" 165 - 172 53 - 54 - 55 M
5' 8" - 5' 10" 172 - 180 56 - 57 
Male Riders Height   
4' 10" - 5 '0" 148 - 152 47 - 48 XXS
5' 0 "- 5' 3" 152 - 160 49 - 50 XS
5' 3" - 5' 6" 160 - 168 51 - 52 - 53 S
5 6" - 5' 9" 168 - 175 54 - 55 M
5' 9" - 6' 0" 175 - 183 56 - 57 - 58 L
6' 0" - 6' 3" 183 - 191 58 - 59 - 60 XL
6' 3" - 6' 6" 191 - 198 61 - 62 - 63 XXL

The above is my personal guidelines, so seek expert advice and ask lots of questions before buying a bike.
You must ask some of the following questions to get the best bike for you.
What do you need the bike for, how often will you ride, will the terrain be flat or hilly or technical, do you want a bike

just for comfort or racing or riding style or simialr position to your current bike?
Do you currently suffer form aches and pains during cycling? What injuries have you that will help you decide what bike you need?
Then decide what you can afford. Often the bike you need is cheaper than your budget, spending more money is not always better.
Geometry of bike wheels (light weight Racing or Aerodynamic wheels will have a huge impact on cycling performance)

I have been setting up peoples bikes for correct bike position for more than 18 years so if you need a bike fit contact me