Self centreing

[G3CWI]

When I had the bike up on a stand the other day I noticed that the handle bars have a slight tendency to self-centre. I slackened the allen key at the top of the stem slightly. Is that the right thing to do? Do all headsets tend to self-centre after a while?

 

[Hacienda71]

It may be the gear cables pulling slightly from either side if the bars are twisted from straight ahead.

 

[Broadside]

When I had the bike up on a stand the other day I noticed that the handle bars have a slight tendency to self-centre. I slackened the allen key at the top of the stem slightly. Is that the right thing to do? Do all headsets tend to self-centre after a while?

Being pulled straight, or do they settle in a spot? Worn headset bearing races may become pitted causing the bars to settle in a position, if this is the case you will feel the steering is a bit notchy almost like its indexed.

I wouldn't undo the preload Allen bolt; that and the two pinch bolts should be left secure.

 

[byegad]

More likely the head race is worn and needs replacing! To test disconnect all cables from the brakes and gears, if it still self centres the races are dimpled and need replacing.

 

[raleighnut]

^^^^ ditto, head races are worn or possibly the cage has 'knife edged'. If worn/dimpled its replace the lot or if the cage has 'knife edged' you may get away with just changing the bearing race but it will only get worse.

 

[mrbikerboy73]

If the bike was on the stand in such a way the front wheel was lower than the rear wheel I.e tilting forward at the front, the front wheel will naturally self centre or point directly forward. If it does not, the headset is too tight or the bearings are knackered. Providing there is no play when applying the front brake and rocking the bike back and forth, I'd hazard a guess and say all is well. I hope this helps!

 

[screenman]

I am slightly worried in that you are loosening important parts without having a clue what you are doing. Please, for your sake nip it back up to where it should be.

 

[Brommyboy]

When my touring cycle developed the tendency to self-centre its steering, I replaced the caged balls with loose ones of the same size. As far as I can remember, there were 16 in the cage, but 25 loose ones fitted (leaving a space of more than one for movement). I have had no further trouble despite doing some tens of thousands of miles since then. The lack of balls in a cage cause the ball race to become indented as the individual pressure per ball is far greater.

 

[Tim Hall]

I am slightly worried in that you are loosening important parts without having a clue what you are doing. Please, for your sake nip it back up to where it should be.

Surely in the case of a threadless headset, the top cap (allen key at the top of the stem) can be dispensed with once the bearings have been loaded and the stem bolts tightened. If it's a threaded headset, that's a different matter.

 

[screenman]

Surely in the case of a threadless headset, the top cap (allen key at the top of the stem) can be dispensed with once the bearings have been loaded and the stem bolts tightened. If it's a threaded headset, that's a different matter.

Tim the problem as I see it is the guy has limited knowledge of bike mechanics, which is why I said be careful.

I am quite aware having 7 bikes here with aheadsets fitted and a couple with the quill style what the difference is and how they work.