How to Adjust Your Bicycle Seat Height

How to Adjust Your Bicycle Seat HeightThe bicycle seat height is one of the most adjustable parts of the bicycle and the most important to ensure you get the best fit on the bike. In this article we discuss how to do it. To adjust your seat height you use a metric hexagonal wrench set. The hexagonal bolt is located on the bicycle frame at the bottom of the seat tube. When you loosen it off you can then move the saddle when applying a small amount of force. If you loosen it too much you will lose your current saddle height setting. So try to avoid this unless you’ll need to start your saddle height tuning from scratch again. Adjusting your saddle height will take a little trial and effort to get right. Gradually raise or lower or lower the saddle and ride the bicycle for a few moments to check if it is at a comfortable height.

To get a rough starting point for the correct the saddle height place the heals on the pedals and rotate the pedals backwards, ensuring the your hips are not rocking from side to side in order to reach each pedal as you rotate your feet.  To do this you can ask someone to hold you on the bike to take your balance or you can set yourself up in a home trainer.
For a more accurate and advanced method to getting the correct seat height, and the method I use is to clip in both feat to your pedals and then measure the angle of your knee joint while each foot is at the most bottom of the stroke. It’s important that when you take this measurement that your feet are in a neutral, or flat, cycling position at the bottom of the stroke.

To do this method you’ll need someone to use a goniometer to measure the angle of your knee. The ideal angel is 27-37 degrees.

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Illustrations sourced from bikefit.com

I personally prefer to error on the side of a lower seat. This is to enable me to get a good clean stroke through the bottom of the pedal stroke. I feel that this is particular important when climbing hills where you need to developed good power at low cadences.

One of the most common signs of an incorrectly set seat height is knee pain. If the seat is too height then you’ll get knee pain at the back of your leg behind your knee. If the seat is too low then you’ll get knee pain at the front of the knee just below the kneecap.

Continual saddle sores are also an indication of the seat being too high. This is due to the friction caused when rocking from side to side in order to get to the bottom of the stroke under load and at low cadences.

Okay, so now the saddle height is perfectly set it’s time to get the seat level. This is the angle of the saddle with respect to the ground and set its and forward position (You can move the saddle forward or backward a few centimetres).

To adjust these two things you need to loosen the bolts located under the saddle, at the top of the seat post. Look under the saddle and you should find it easily. Here again, the same principle apply. Only loosen the screw so that you can move the saddle but it should not move easily if you are not applying forces on it.
When the bicycle is on flat ground the saddle angle should be almost parallel to it. I use a builder’s level across the top of the seat to check this. If you feel like you are slipping either backward or forward as you ride the bike you may need to adjust this.

To set the forward position of the saddle you take a plumb line and have it drop from the front of the knee through the pedal spindle. The forward position of the saddle is governed mainly by your thigh length. Move the saddle forward or backwards to ensure that you get the plumb line drop through the pedal axle as shown below:

bike fit 03Illustration sourced from bikefit.com

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