Wobbly headset
Discussion
Noticed the roadie headset had a bit of play in it yesterday, whipped the bars and stem off thinking it would be an easy fix but the play is still there, top bearing race doesn't seem to fit flush either as there is about a 1mm gap between the bearing race and the top cap that fits between the spacer and the frame.
Any thoughts? Headset was new when serviced in May, assuming its the right one but I'll check tonight....
Any thoughts? Headset was new when serviced in May, assuming its the right one but I'll check tonight....
Assuming its an integrated headset. The bearing should sit flush in the top and bottom of the frame and the fork race and the headset cap should also sit flush to the bearings.
I had a similar issue that you have a while ago. I was sold a replacement bearing for my headset by a LBS only to find it didn't sit flush when on the bike.
First thing I'd do is loosen everything off so the forks drop and then put everything back and reload the headset. If you still cant get everything to sit flush take it back to the LBS that fitted it and ask them to sort it.
P
I had a similar issue that you have a while ago. I was sold a replacement bearing for my headset by a LBS only to find it didn't sit flush when on the bike.
First thing I'd do is loosen everything off so the forks drop and then put everything back and reload the headset. If you still cant get everything to sit flush take it back to the LBS that fitted it and ask them to sort it.
P
Thought I'd fixed but I'm obviously being biff. This is what I have under the top cap, there doesnt appear to be anything underneath that star nut which I'm assuming should be the bung, like this?
So my new question is how does that fit if the black ring at the top "the pat 205335" bit fit low enough into the steer tube to not affect the bolt through the top cap given it looks wider than the silver shim?
And how does the way this one work differ?
And how the hell do I get that star nut out?!...
pablo said:
Thought I'd fixed but I'm obviously being biff. This is what I have under the top cap, there doesnt appear to be anything underneath that star nut which I'm assuming should be the bung, like this?
So my new question is how does that fit if the black ring at the top "the pat 205335" bit fit low enough into the steer tube to not affect the bolt through the top cap given it looks wider than the silver shim?
And how does the way this one work differ?
And how the hell do I get that star nut out?!...
The bung works differently from a star nut. When you tighten the hex bolt it expands and grips the carbon steerer whereas the star nut is more of a brute force approach. You force the star nut into the fork so it sits a few cm below the top of the fork the act forcing the star nut makes it grip to the inside of the fork. To remove the star nut you have to either force it out of the bottom of the fork or hit far enough down the fork so it doesn't interfere with the new bung/star nut. There is a great explanation here: http://www.parktool.com/blog/repair-help/star-fang...
What looks strange to me is that you appear to have a metal liner inside your forks which is something I certainly haven't seen before (I haven't seen that many other than my own)In my opinion that liner should either sit flush to the fork or your headset needs to be such to take those couple of mm into account.
I'm sure someone else will be able to explain it better.
P
It's a carbon fork steerer, cervelo glue an alloy sleeve in the steerer tube which I guess is supposed to be something for the star nut to bind against. It's rubbish and not holding any tension though but I assume that I can't use a bung like those pictured with that alloy sleeve in the tube?
pablo said:
It's a carbon fork steerer, cervelo glue an alloy sleeve in the steerer tube which I guess is supposed to be something for the star nut to bind against. It's rubbish and not holding any tension though but I assume that I can't use a bung like those pictured with that alloy sleeve in the tube?
IIRC you can use the "bungs" in alloy steerers: Hope have been doing it for years with their "Head Doctor".IroningMan said:
Should the alloy sleeve be proud of the carbon steerer tube like that - or is it pulling loose?
That's what doesn't look right to me. Its almost as if headset has been tightened so much that its pulled the sleeve out of the steerer which is causing the headset not to sit flush. You could try placing a bit of 4x2 on top of the sleeve and then tap it flush with the carbon. However I'd be checking with other owners/Cervelo about how it should be first.P
Cervelo owner (and builder of my own here)..
If the sleeve is loose, pull it out, rough it up with a file / coarse sandpaper and epoxy it back in. You can clean up the inside of the steerer tube with fine sandpaper if it needs it, but go easy. Wipe the whole thing off with spirit - acetone (nail varnish remover) is ideal.
Alternatively, give it to someone to sort if you're not happy messing with epoxy (it's pretty simple) Sounds like it's not been done well in the first place, if it's properly bonded to the carbon it's VERY strong.
If it IS properly fixed, leave it there. Don't try to 'tap it down' - you may break the bond, and do bad things trying to force something that doesn't fit: My recollection is that the top of the sleeve is slightly widened (see ascii art below!), and it should not go completely in / flush with the top of the cut - the manual says you always need a 5mm spacer between the top of the stem and the compression cap - you've not changed the stem by any chance? not all stems are the same 'thickness'.. anyways:
The whole assembly (inc the slightly raised sleeve) should sit below the level of the top 5mm washer so you can get some tension into it
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If the nut is pulling up, it may have damaged the sleeve / been over-tightened. Stick the bolt in and tap the star nut down the sleeve a bit - ideally past the slipping point (depending on the length of your bolt), and you may find it will get some bite in a fresh part of the sleeve.
I also seem to recall that the top bearing cap doesn't sit perfectly flush to the frame, there was a (very small) gap, and a shim/gasket supplied to go in there.. I may have hallucinated that tho, it was a couple of years ago..
HTH
[edit after properly reading the OP!]
If the sleeve is loose, pull it out, rough it up with a file / coarse sandpaper and epoxy it back in. You can clean up the inside of the steerer tube with fine sandpaper if it needs it, but go easy. Wipe the whole thing off with spirit - acetone (nail varnish remover) is ideal.
Alternatively, give it to someone to sort if you're not happy messing with epoxy (it's pretty simple) Sounds like it's not been done well in the first place, if it's properly bonded to the carbon it's VERY strong.
If it IS properly fixed, leave it there. Don't try to 'tap it down' - you may break the bond, and do bad things trying to force something that doesn't fit: My recollection is that the top of the sleeve is slightly widened (see ascii art below!), and it should not go completely in / flush with the top of the cut - the manual says you always need a 5mm spacer between the top of the stem and the compression cap - you've not changed the stem by any chance? not all stems are the same 'thickness'.. anyways:
The whole assembly (inc the slightly raised sleeve) should sit below the level of the top 5mm washer so you can get some tension into it
\ /
| |
| |
| |
If the nut is pulling up, it may have damaged the sleeve / been over-tightened. Stick the bolt in and tap the star nut down the sleeve a bit - ideally past the slipping point (depending on the length of your bolt), and you may find it will get some bite in a fresh part of the sleeve.
I also seem to recall that the top bearing cap doesn't sit perfectly flush to the frame, there was a (very small) gap, and a shim/gasket supplied to go in there.. I may have hallucinated that tho, it was a couple of years ago..
HTH
[edit after properly reading the OP!]
Edited by upsidedownmark on Tuesday 18th June 10:26
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