Loose Headset

[slowandsteady]

My headset keeps loosening up slightly and I get that telltale "jolt" when I use the front brake. I have tightened it a few times and re-tightened all the bolts (properly I think) but it comes back after 50-100 miles or so. I have about 4cm of carbon spacers under the stem and 1.5cm above the stem. I have a total steerer length of 350mm and it is a steel IF fork. The adjuster bolt inside the steerer feels pretty tight when i go to adjust it...

Think I just found my own answer:
http://forums.thepaceline.net/showthread.php?t=51921

I'll give these suggestions a go and report back to the forum.

[ultraman6970]

Which bike is it?? sure the headset is set up right? have seen people putting stuff backwards more than once.

Sure the crownrace is not lose?

[slowandsteady]

Ultraman: IF Steel Crown Jewel -HS is definitely set up right. I have a feeling the plug is working its way up the steerer. I'll check it over the next few rides.

[ultraman6970]

Hmm... if you have an expander there is a big chance it is not the right size, the problem with expanders is that they need to have the right size or they wont be tight in the steering column. If your fork steering column the best is just go with a star nut.

[David Kirk]

When it comes loose do you get a slight knock when you hold the front brake on and rock the bike back and forth? If so then I'd say there is a good chance your stem isn't clamping the steerer well. Remember - the top bolt only sets the preload on the bearings and it's the stem that holds this adjustment. Assuming it's a carbon steerer I'd make sure both the stem and steerer are clean and then give each a light coat of carbon paste and then set your preload and tighten. It should be fine then.

If on the other hand you get an occasional single clunk without the free-play knock when holding the front brake on and rocking the bike fore and aft then there is a good chance that it's the headset crown race shifting on the fork. This would indicate that the fork is either undersize or the race is oversize. It can be fixed with a knurling tool but no amount of headset adjustment will fix it.

I hope that helps.

dave

[slowandsteady]

When it comes loose do you get a slight knock when you hold the front brake on and rock the bike back and forth? If so then I'd say there is a good chance your stem isn't clamping the steerer well. Remember - the top bolt only sets the preload on the bearings and it's the stem that holds this adjustment. Assuming it's a carbon steerer I'd make sure both the stem and steerer are clean and then give each a light coat of carbon paste and then set your preload and tighten. It should be fine then.
dave

Dave - Exactly as described above - hmmm, stem bolts seem pretty tight. It's a steel steerer so I am not "babying" the bolts without a torque wrench. I'll check 'em again though.

[David Kirk]

Dave - Exactly as described above - hmmm, stem bolts seem pretty tight. It's a steel steerer so I am not "babying" the bolts without a torque wrench. I'll check 'em again though.

In that case it sounds like the stem isn't grabbing the steerer well. Remember - the top bolt is not meant to hold the headset adjustment - it's only meant to set it and the stem holds it.

I'd still try carbon paste - it's not just for plastic any more! It makes everything grip better.

dave