During short trips, such as going to the office, going shopping, etc., we often do not realize the importance of properly adjusting the bike to our form. In fact, we only apply some basic settings (saddle and handlebar heights) on an « almost » basis. However, riding the same bicycle for tens of kilometers (or even hundreds of kilometers) will inevitably cause discomfort due to poor adjustment of the bicycle.
This shows that « approximately » adjustments are no longer sufficient, and even very precise adjustments require some calculations. You can of course do it in professional workshops like Decathlon, but it’s also important to learn how to do it yourself.
some measurements are necessary
To calculate, we need numbers. So start by measuring your body: Standing with your back against a wall and a book between your legs, measure your height and the distance between the top of the book and the floor. Below, we refer to this measurement as your inseam length (E).
bike settings
First, you have to adjust the height of the saddle. Then multiply your inseam length by a factor of 0.885 (depending on the length of the frame).
The saddle indent (R) can also be adjusted according to your inner leg length (E). Here are some measurements: If E is between 75 and 78 cm, R must be 4 to 6 cm. For 79 to 82 cm (E) you need 5 to 7 cm (R); 6 to 8 cm for 83 to 86 cm; 87 to 90 cm for 7 to 9 cm…
Seat-handlebar distance (S) as above: for 75 to 78 cm (E) you need 47 to 51 cm (S); 79 to 82 cm (E) 50 to 54 cm (S); 53 to 57 cm for 83 to 86 cm; 87 to 90 cm 56 to 60 cm…
Saddle bar spacing (D) is also derived from crotch length: 75-78 cm (E) requires 5-6 cm (D); 6 to 7 cm is 79 to 82 cm, 7 to 8 cm is 83 to 86 cm , 8 to 9 cm is 87 to 90 cm.
You also have the width of the hanger, which must correspond to the width of your shoulders. Since this width cannot be adjusted, you must choose your bike accordingly. If the handlebars are too narrow or too wide, you’ll be hampered on long rides. The same goes for frame length: you have to choose a bike based on your overall length, bust length and arm length so that your stance is neither too forward nor too upright. Important note: try out a few road bikes before buying. Don’t hesitate to ask the store to try it a few hundred meters away to see if it suits you.