Desired use, weight, quality of components, price – just a few very important attributes for
choosing a bike. None of the above matter if the bike does not fit.
Riding an improperly adjusted bike is painful. If your knees or back are in pain or your seat is killing you, the most likely reason is fit.
How am I an expert? I bought my bike and adjusted it for 6 months, searching the Internet for tips and explanations, until I got it right. I have a mountain bike, so while the tips below may help with road bike, I am sure there is a number of things I simply don’t know. Also, there are other adjustments you could make to improve performance, but these 4 are an absolute must – read on.
Correct seat height is essential for pedaling. A seat that is too low results in knee burn, a seat that is too high makes you tilt sideways to reach the bottom pedal, and both result in reduced performance, i.e. make you work harder.
You want your seat so high that your leg extends almost all the way through the stroke. Easy way to measure that is to raise your seat up until your heel just touches the pedal when the leg is fully extended while sitting in the seat.
(This is quite high, only tips of your toes will be able to touch the ground, so use some sort of step for your other foot to keep sitting in saddle while making adjustments.)
Seat forward/backward position
In concert with stem length, seat forward/backward position controls where you are in relation to the pedals. Symptoms of wrong seat position are too much weight on hands, or slipping from the saddle forward or backward all the time. Back pain when pedaling uphill may also point to a seat that is too far back.
For efficient pedaling and quiet forward/backward body position you want your center of mass to be above your bike’s bottom bracket (crank hub). You also want you pelvic sit bones to be on meatiest widest part of your saddle. (If you are female and ride male saddle, please get yourself a women’s saddle)
To test, have someone to hold you bike while you are standing on the pedals. The pedals should be horizontal. Now, without pulling or pushing handlebars forward or backward, slowly lower yourself. The point where your bottom touches the seat is where the seat should be.
To adjust, you can move your seat, obviously, and change length of your stem (piece of pipe that connects handlebars with fork’s steering tube): shorter stem moves you backward and vice versa. (note that this also changes your body angle, which moves you center of mass in opposite direction, so always test the adjustments; additionally, shorter stems make steering response quicker, which at some point could feel jittery).
If you’re out of adjustment, you need another frame. (This is why it is a good idea to do these adjustments while trying/buying a bike)
Seat angle probably contributes the most to saddle pains. (If you are female and ride male saddle, please get yourself a women’s saddle)
As mentioned above, you want your pelvic bones on the cushiest part of the saddle. You also want widest portion of the bones in contact with the saddle, while avoiding the front of your saddle pinching the nerves on the inside-front of the pelvis.
Anyway, ride in normal body position for some time. Now try riding leaning forward a bit – does it feel better? Does leaning backwards feel better? Tilt the seat a bit to make you normal riding position feel better, repeat. Don’t worry if it takes 5 tries, or next morning you need to start anew – this is very delicate adjustment. (In my case, the adjustment is done by the same screws used to clamp fore-aft position).
It takes several hours of riding to get this right.
This must be done right after seat height, but the other settings are MUCH more important.
Low handlebar helps with climbing – you could lean forward more (to get your center of mass over bottom bracket when climbing a hill), but more of your weight will be on your hands when riding on a flat surface. High handlebars feel great – you sit straighter, but they are worthless for climbing.
I found handlebars at seat height to be the best compromise.
- How to Fit a Bicycle by Peter White Cycles
- Best illustration of bike seat and pelvic bones by Nextride
- Great article about seats by Bike Test Reviews