A Head Set Problem

Joe’s daughter has a problem with the head set on her BMX bike, it is stiff and probably crunchy when they turn the handle bars from side to side, this is a problem all bikes can have. Here is our diagnosis.

Question:
The steering on my daughter’s BMX bike has become very sticky and clunky. When I turn the handlebars from side to side it is not smooth. How can I repair this problem?

Hi Joe,

The problem is that the bearings in the head set are either dry, without any grease, or has grit or a broken ball bearing in side or the surface that the ball bearings run on are scratched or pitted and are rough. All these reason will cause the steering to be crunchy and far from smooth, just the same as the hubs or the bottom bracket if they get worn.

My first suggestion is that if you don’t know what you are doing and maybe don’t have the tools for the job would be to take the bike to a good bike shop with a good repair department, they will sort it all out by probably fitting a new head set or possibly re-greasing and adjusting the old one. This is much the easiest method and seeing as it is a BMX the head set has probably taken a few bumps over the years.

If you feel like trying to fix the problems yourself then you will need an Allen key or a spanner and a big adjustable spanner and probably a special flat head set spanner, some grease and a bit of luck on your side! First you need to loosen the bolt that holds the handle bar stem in, for this you need either an Allen key or a spanner, the bolt is the one on the top of the stem. Loosen the bolt a few turns, not all the way out; you will probably have to tap it with a hammer just to nock it down. Once you have done this the stem will just pull out. Then there should be a very big nut holding the head set down, this you need to undo and the bearing cup that is bellow it with the big adjustable spanner. This is where you need some luck and hope that all the bearings don’t fall out, if they do you are going to have to hunt for them.

Grease the top bearings and the bottom bearings which are at the top of the forks and then reassemble everything in reverse of taking them apart. You need to adjust the top cup so that the forks turn smoothly without being loose and tighten the big nut to hold everything together. The trickiest bit is being able to hold the top cup while tightening down the top tube, usually you need the special flat head set spanner to hold it while you tighten everything up.

Good luck and think about taking the bike to the bike shop as you might have to in the end anyway.