Riding Position, Why is it important?
There is so much information available on bike riding position, it can be confusing to both beginners and experienced riders alike. There is a whole industry on top of the bike industry dealing with bike fit, and you can spend a great deal of money on saddles, bars, stems, and a bike fit.
So let’s forget about computer programs and magic formulas, and look at the basic issues we are dealing with. Assuming you’ve got the right size, how can we find a good place to start? Find a position that is both efficient and comfortable.
There are really only two main issues we concern ourselves with when setting up customers. That is saddle height, and position of your arms in relation to your legs (cockpit set up). Whether you are looking for an extreme aero racing position, or a more upright leisure riding position, the same principle applies. You need an efficient position, whether your goal is to go fast, or ride in comfort. We can help with that.
Imagine you are doing squats with a weight. Note that when in the lowest possible squat, the knees are spread apart. That is because the hip joint in the pelvis has a limit to how far it can travel. When you reach that limit the only way to squat any lower is to spread the knees apart.
When you see someone on a bike riding with their knees spread, it is often an indication that their saddle is too low and the hip joint has reached its limit of rotation. An extremely low back position, or the saddle positioned far back will exacerbate the problem because you are rotating the pelvis forward. However in most cases if the saddle is high enough, no matter how low your back, at the top of the pedal stroke, the hip joint will not be at or near its limit.
When doing squats with a weight it is hard to lift from the lowest position. It would be much easier if you started from the half way position. In other words, leg muscles work more efficiently near the top end of the lift. So if you can ride a bike with the saddle as high as it can be, you are pedaling with more efficiency that with the saddle set low.
How high would be too high? Well, if you are stretching for the pedal at the bottom of the stroke, and your pelvis is rocking side to side, it would indicate your saddle is too high. With one crank at its lowest point, your toe should be pointing down, but not stretched. You should be then able to lift your butt 1/4 inch (6mm) above the saddle. If you can lift yourself more than that, your saddle needs to go higher. When riding, it is easier to tell by feel if a saddle is too high, but not so easy to tell if it is slightly too low.
Position of arms in relation to the legs.
When pedaling at maximum effort we are pushing down with more than our body weight. The only thing holding us down is our hands grasping the handlebars. Power is transmitted through the arms, shoulders, and back muscles to the legs.
Many recreational riders make the mistake of raising their handlebars higher and higher to achieve a more upright back angle, when a better approach might be to fit a shorter stem and raise it less. (The resulting back angle is the same.) If the arms are not opposing the legs, backache can result, or you find yourself constantly sliding forward on the saddle.
Weight distribution too comes into account. Weight should be distributed between the pedals, saddle and handlebars. If the bars are above the saddle then all the weight is on the saddle.