Dave Moulton

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Tuesday
May092017

Riding Position Simplified

There is so much information available on bike riding position, it can be confusing to both beginners and experienced riders alike. A whole cottage industry has sprung up dealing with bike fit, and one can spend a great deal of money, and often be no better off.

So let’s forget about computer programs and magic formulas, and look at the basic issues we are dealing with. Assuming our bike is the right size, and not too big or small by extremes, 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 need to concern ourselves with. That is saddle height, and position of your arms in relation to your legs. 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.

1.)    Saddle height. Imagine you are doing squats with a weight as shown in the picture above. 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.

2.)     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.

Look at the top picture of Peter Sagan. With the crank arms horizontal and the pedal on its downward stroke, the red line line drawn from the hip joint to the pedal, is approximately parallel to a line drawn from the shoulder to the hands on the drops. In other words arms are in exact opposition to the legs.

Notice I said approximately. The lines do not have to be exactly parallel, but if there is a wide difference this is not a good position. It doesn’t matter what your back angle is, horizontal or a leisurely 45 degree angle. Arms opposing legs still apply.

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.

 

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Reader Comments (7)

This post has really interesting information, thank you. It is a quite concise technique that is also simple to check.

However I miss some detail on the last sentence of the penultimate paragraph: When happens the backache/sliding-forward in relation to the acute/obtuse angle between the two lines you mention?

May 10, 2017 | Unregistered CommenterPedroMJ

PedroM,

Imagine carrying a 30 or 40 lb. box at arm’s length. All the strain would be on your arms, shoulders, and lower back. You would naturally carry the box closer to your body to ease the strain. Riding a bike you can’t move the handlebars closer to your body, so you slide forward to the tip of the saddle which is both uncomfortable and has the effect of the saddle being too low. With arms opposing legs, there is less tendency to do this.

The tendency to move the body forward is natural, it is why we get out of the saddle when the going gets tough. A child will do it without any training from an adult. I discovered this in the 1950s when I started racing. Seat angles were 71 degrees, and top tubes were long. There was a theory that one had to sit back and low in order to pedal efficiently, a notion that dated back to the high wheeler of the late 1800s.

It is how I first got into framebuilding, trying to build something that suited me better. Read Old Bike Desgns Die Hard.
Dave

May 10, 2017 | Registered CommenterDave Moulton

KISS is still true, keeping it simple is best.
Follow these suggestions and you are 95% of the way to a great fit.
The only time I find that I need exact measurements of distance and angles is when I am trying to get two different bikes to feel the same.

May 10, 2017 | Unregistered Commenteredstainless

Very interesting! Thanks Dave, I'm all about simplifying!

How does the parallel arm/leg lines argument work though when you're not working your hardest? Most of the time you're not pulling on the bars, but should have a relaxed grip and all the work is in the legs.

May 10, 2017 | Unregistered CommenterRubeRad

Also (but maybe this is getting beyond the simplified version), in addition to saddle height there's the forward/back question, and KOPS (which may be a myth)

May 10, 2017 | Unregistered CommenterRubeRad

Comfort to me is the most important thing on a bike, In my day, a bit before Daves, We did not have all the different stems and bars saddles etc could NOT afford them, So we had to make do with what we had. A larger frame was the thing then, along with bigger wheels, most riders changing from 26" to 27" in the late 1940s early 1950s Ride better is what we were told? We still with what we had did some pretty good times in races, Of course now with all the custom fitting that we can get, I am sure that then if we had had this we would done even better times,Also the diet and eating better would have made a big difference, I still ride with my saddle back as far as it will go.Just feels better for my way of riding, Very hilly were I live and I find that this helps with climbing in the saddle You cant teach an OLD dog new tricks as they say? But as usual Dave brings out good points and well worth a read

May 10, 2017 | Unregistered Commenterjohn crump

hi Dave!
thank you for your post!
i totally agree, specially when pulling on the handlebars.
but what about the other situation, where we rest, push, support ourselves on the handlebars? this situation, in cycling, in my opinion, happens... 99% of the time.
best regards,
Mircea

May 17, 2017 | Unregistered CommenterMircea Andrei Ghinea

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