Racing riders have low handlebars so they can crouch aerodynamically. They are usually below the seat 2-4". Comfort riders or beginners will have handlebars level with the seat or higher. [1] X Research source
You can buy more spacers at your local bike shop if you need the handlebars to get higher.
If you are working with delicate pieces, like a carbon fiber frame, you should have a torque wrench to make sure you don’t crack anything. [3] X Research source Make sure you can turn the handlebars freely. If not, you should loosen the head bolt slightly until you can easily turn the bike.
If you are having trouble keeping the bars in place, tighten the nuts a quarter turn so that you need more pressure to spin the handlebars, yet they still move independently of the wheel. [4] X Research source Tighten the bolts when you are done and the handlebars are aligned.
If you are struggling to turn or feel a “tight-spot,” loosen the top bolt a little. [5] X Research source
Threadless headsets have one big bolt on the top and two smaller bolts that help clamp the stem down. If your bike only has one continuous piece of metal connecting the bike to the bars then you have a threaded headset.
Some bikes do not have a hex nut by the frame, and just have the bolt on the top of the stem.
Road bike: Handlebars on racing bikes should be slightly lower than the seat to provide optimum aerodynamics and control at high speeds. Mountain bike: Mountain bike handlebars should be lower than the seat. This gives you a lower center of gravity and better balance when negotiating rugged terrain. Cruiser: Handlebars on standard bikes should be slightly higher than the seat to limit strain and provide maximum comfort.
Angling the handlebars is a minor adjustment. If you can’t reach the brakes, have to bend over uncomfortably, or must extend your arms all the way, you will need to purchase a new handlebar stem. You may also be riding a bike that is too big for you. [8] X Research source Position the brake levers so they’re pointing at a 45-degree angle toward the ground rather than keeping them parallel. [9] X Expert Source Jonas JackelOwner, Huckleberry Bicycles Expert Interview. 18 February 2020.
In many ways, handlebar angle is a matter of personal preference. As long as you are comfortable, they will work. If you’ve been having finger numbness when riding, consider tipping your bars up a little more. This puts less pressure on your palms that may cut off some circulation.
If you have a torque wrench you should set the bolts to 5nm strength. [11] X Research source Be sure to tighten the handlebars completely, or you may strip the bolts holding them to the stem and make your bike unsafe to ride. [12] X Expert Source Jonas JackelOwner, Huckleberry Bicycles Expert Interview. 18 February 2020.
