By Andrew Reimann

Mechanical Monday: Discovering a Loose Headset and Fixes

Strange, rhythmic noises can be annoying while riding a bicycle. They often signal that something is mechanically off with a bike, such as a creaking bottom bracket, or at the very least, something isn't running like it is supposed to, like a misaligned speed sensor magnet that hits a computer. Noises are perhaps even more annoying than getting multiple flats in a row (be sure to read our last mechanical Monday on the five different kinds of flats you might see).

One non-rhythmic noise that many riders put up with is a loose headset. The most obvious symptom is a chattering sound on a ride that occurs every time a rider squeezes the front brake. This is a problem that shouldn't go ignored, especially because it can lead to serious handling issues with the bike along with the possibility of catastrophic fork or frame failure.

There are a few ways to check for a poorly adjusted headset; one of the best is simply bouncing the front wheel of a bike and listening for a rattling noise, like we've done in the video below:

When you are listening for rattling like we have, be sure that the front wheel is correctly installed. A front wheel with a loose quick release doesn't sound too different from a loose headset, although both should be fixed immediately. If you have a bad ear for noises, another, although slightly less reliable way to check for a loose headset, is to try to spin the spacers or the top cap. In the video below, we demonstrate what loose headset spacers and top caps look like:

However, it is possible to have a loose headset with spacers that are nice and tight. If you are unsure, and your bike rattles when you use the front brake, it is best to take it to your nearest bike shop. If you are confident in your ability to access and DIY fix a loose headset, we have a few pointers.

First, always undo the bolts on the stem first and tighten them last.

That bolt on the top cap only preloads the headset. A common problem I see as a mechanic is people attempting to fix their headset by tightening down that top cap bolt as hard as they can without undoing the stem bolts. This means that the top cap is fighting the stem. There is no winner in this battle, but the loser usually is the star nut or compression plug, which rips out of place and ruins the inside of the fork's steerer tube. I should repeat the first rule of adjusting headsets: always undo the bolts on the stem first and tighten them last.

After the stem bolts are loose, then tighten the top cap. There is no reason to tighten this down as hard as you can, and doing so will not only make the steering feel awful, but it will seriously wear the bearings in your headset. While most headset manufacturers have their own torque specs, if you are forced to do this job on the side of the road, a good rule to follow is to incrementally tighten the top cap bolt until you can no longer spin the headset spacers.

After the top cap bolt is properly tightened, be sure to align the stem with the front wheel, and then tighten the bolts on the stem back to the manufacturer's recommended torque, which unlike a headset, is often etched or displayed on the stem itself. If you don't have a torque wrench handy, and don't have the mechanical experience of gauging torque by feel, best to either get the right tools or let a trusted mechanic tighten those bolts for you. Too little, and your stem won't control the front wheel while riding. Too tight, and you could crush the steerer tube from the outside in.

Want to learn more or practice adjusting headsets in front of a professional mechanic? Von Hof is having a free roadside repair clinic on March 21st (a Monday night). If you haven't already, be sure to sign up for our newsletter to stay up to date with all the Von Hof rides, clinics, and events.