No matter how beautiful or mechanically perfect a bicycle may be, if it doesn't fit the rider properly it will be no good. There are many ways to measure a bicycle, and even more opinions on how to measure a bicycle properly. This is because even two people of the same height may have different length arms and legs or simply have a different riding style. Add to this that different types of bicycles such as a mountain bike or a modern racing bicycle have different frame shapes. The sizing chart discussed below speaks specifically to vintage racing bicycles.
Luckily, with just two measurements, your height and your inseam, its easy to find the correct frame size for you. The frame is like the heart of a bicycle, once you have the correct frame size you will be able to make adjustments to the saddle and steering to make it fit just right.
Finding the correct frame size
1. Rider's inseam height versus bicycle's standover height
This measures the distance between the top tube of a bicycle and the ground. This is used to make sure that you are able to stand on your feet over your bicycle - important for stopping! You want at least 3 cm's of space (clearance) between your inseam (crotch) and the top of the bicycle tube. In other words look for a bicycle which has a stand over height at least 3cm lower than your inseam.
To measure your inseam take your shoes off and stand your feet flat and your back against a wall. Place a thick book between your legs and push it up so that it is acting like a bicycle saddle while keeping it level. Then using a tape measure the distance between the book's spine and the floor. This is your inseam. Do it a couple of time to make sure you have measured it accurately. It is a bit easier if you have someone to help you.
2.) Rider's height versus bicycle frame's height
We measure our vintage racing bicycle's from the center of the top tube to the center of the seat tube on the bicycle frame. This is a very quick and easy way to match a bicycle frame to a rider's height using a sizing chart. There are overlaps between frame sizes so it is common to fit two different sizes. For example, someone who is 160 cm tall could fit an extra small or small frame.
|
Size |
Rider height |
Frame size |
|
Extra small |
1.52 – 1.60 m |
50 – 52 cm |
|
Small |
1.57 – 1.65 m |
52 – 54 cm |
|
Medium small |
1.63 – 1.70 m |
54 – 56 cm |
|
Medium large |
1.68 – 1.75 m |
56 – 58 cm |
|
Large |
1.73 – 1.80 m |
58 – 60 cm |
|
Extra large |
1.78 – 1.85 m |
60 – 62 cm |
|
Extra extra large |
1.83 – 1.91 m |
62 – 64 cm |
Adjusting racing bicycle for perfect fit
Once you have a bicycle frame that fits your height and inseam you can further adjust the saddle and steering; height, position and angle for a snug fit.
Saddle adjustments: