Basic Bicycle Fitting: Adjusting the Seat and Handle Bars
To better fit your bike to you, try adjusting the seat and handle-bar positions.
Most seats take an allen wrench hex head bolt to loosen the position of the seat. The bolt is located under the seat.
The Saddle/Seat’s Angle
Saddles should be set with their tops level, or parallel, to the ground. Tilting the saddle’s nose up is uncomfortable. Tilting the saddle’s nose down will cause you to drift forward onto the handlebars. Pushing against the bars might make your shoulders tense up.
To determine correct height, sit on the saddle with both heels on the pedals, and pedal backwards slowly. The saddle is at the correct height when each leg straightens fully as the pedal passes the bottom. Your hips should remain level on the saddle. If they roll, the saddle is too high and your legs may over-extend, which can damage your knee joints. If your knee is bent when the pedal passes the bottom, the saddle is most likely too low. Some new riders may prefer a slightly lower saddle height, so they can reach the ground more easily. This is better for your knees than having your saddle too high. Setting the saddle height with your heels on the pedals, ensures your knees will have a slight bend when you put the balls of your feet on the pedals. This keeps knee joints stable and protected.
Front to Back
Bring the cranks parallel to the ground, then place the ball of your foot on the front pedal. If the saddle is in the correct position, a line drawn from behind your kneecap would fall through the pedal’s axle.
Ride with the new position for at least a couple of weeks before making any changes, and then only make small changes of not more than 5 mm at a time.
Correct height allows for you to lean forward comfortably, without straining your back, neck, or wrists. Depending on the type of bike you ride, and your flexibility, you may want to adapt these guidelines slightly. If you’re not particularly flexible, you may prefer a higher or shorter handlebar stem in order to bring the bars in closer and allow yourself to sit more upright.
You can change the angle of your handlebars by loosening the handlebar clamp on the stem and rotating the bars. Try out all of the hand positions you’ll use when you ride to make sure the angle is comfortable. Remember to tighten the clamp when you’re through.
Your stem sits on a stack of spacers, and is clamped to the steering column by two 5 mm Allen bolts. An adjusting cap sits on the top of the column, and is anchored by another 5 mm bolt. You can change the height by removing some spacers, but be aware that doing so may change the headset adjustment (the bearings in which the fork turns). To make sure it isn’t too loose or too tight, it might be best to have this adjustment done at a bike shop.
Brake Lever Postions
It seems some people over look the brake lever placement. The lever should be about a 45 degree angle downwards for mountain, hybrid, comfort, and kids style brake levers. Your fingers shouldn’t have to be raised up and out to reach the brake lever. They should fall right down on it. For road bikes, the bottom of the lever blade should line up with the bottom of the drop in the bars. Facing forwards should look pretty level.
Various Sizing Charts are provided below for your reference.