A Cycling & bikes forum. CycleBanter.com

Go Back   Home » CycleBanter.com forum » rec.bicycles » Techniques
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Perpetually loosening threadless headset...



 
 
Thread Tools Display Modes
  #1  
Old November 7th 08, 06:22 PM posted to rec.bicycles.tech
Dave
external usenet poster
 
Posts: 78
Default Perpetually loosening threadless headset...

I have a Santa Cruz Blur mountain bike with a Chris King threadless
headset. In order to keep the headset from creaking due to fore/aft
movement, I have to retighten it every ~10 hours of ride time. I am
confident that the fore/aft movement is from the headset and not the
fork bushings (Rock Shox Reba fork w/alloy steerer) because the noise
disappears after retightening. The top cap has ample clearance over
the top of the steerer so its not bottoming, and the stem has plenty
of clamp area, although I run the stem with no spacers above, so the
clamp extends over the top of the steerer. I bought the bike used in
pristine condition so I very much doubt there's any crash damage.

The headset cups appear to be seated properly. The only cause I can
think of is a poorly faced headtube or misaligned crown race. I was
told that a good test is to disconnect the front brake, remove the
handlebars, and rotate the stem 360 degrees, feeling for variations in
resistance due to misalignment. I did this and could not detect any
variation.

Can anyone advise as to whether the test outlined above is a reliable
way to check for misalignment? Any other hints for troubleshooting
this?

I'd prefer to exhaust all my other options before shelling out the
bucks to have the headtube re-faced.
Ads
  #2  
Old November 7th 08, 06:43 PM posted to rec.bicycles.tech
Bill Sornson[_3_]
external usenet poster
 
Posts: 254
Default Perpetually loosening threadless headset...

Dave wrote:
I have a Santa Cruz Blur mountain bike with a Chris King threadless
headset. In order to keep the headset from creaking due to fore/aft
movement, I have to retighten it every ~10 hours of ride time. I am
confident that the fore/aft movement is from the headset and not the
fork bushings (Rock Shox Reba fork w/alloy steerer) because the noise
disappears after retightening. The top cap has ample clearance over
the top of the steerer so its not bottoming, and the stem has plenty
of clamp area, although I run the stem with no spacers above, so the
clamp extends over the top of the steerer. I bought the bike used in
pristine condition so I very much doubt there's any crash damage.

The headset cups appear to be seated properly. The only cause I can
think of is a poorly faced headtube or misaligned crown race. I was
told that a good test is to disconnect the front brake, remove the
handlebars, and rotate the stem 360 degrees, feeling for variations in
resistance due to misalignment. I did this and could not detect any
variation.

Can anyone advise as to whether the test outlined above is a reliable
way to check for misalignment? Any other hints for troubleshooting
this?

I'd prefer to exhaust all my other options before shelling out the
bucks to have the headtube re-faced.


Try wrapping a bit of plumber's tape around the base of the steer tube,
under the race. (Over it is OK, too.) Sometimes the looseness originates
down there, though it's "felt" at the headset.

Billl "Master Mech Mickey...not" S.


  #3  
Old November 7th 08, 07:01 PM posted to rec.bicycles.tech
Lou Holtman[_3_]
external usenet poster
 
Posts: 881
Default Perpetually loosening threadless headset...

Dave schreef:
I have a Santa Cruz Blur mountain bike with a Chris King threadless
headset. In order to keep the headset from creaking due to fore/aft
movement, I have to retighten it every ~10 hours of ride time. I am
confident that the fore/aft movement is from the headset and not the
fork bushings (Rock Shox Reba fork w/alloy steerer) because the noise
disappears after retightening. The top cap has ample clearance over
the top of the steerer so its not bottoming, and the stem has plenty
of clamp area, although I run the stem with no spacers above, so the
clamp extends over the top of the steerer. I bought the bike used in
pristine condition so I very much doubt there's any crash damage.

The headset cups appear to be seated properly. The only cause I can
think of is a poorly faced headtube or misaligned crown race. I was
told that a good test is to disconnect the front brake, remove the
handlebars, and rotate the stem 360 degrees, feeling for variations in
resistance due to misalignment. I did this and could not detect any
variation.

Can anyone advise as to whether the test outlined above is a reliable
way to check for misalignment? Any other hints for troubleshooting
this?

I'd prefer to exhaust all my other options before shelling out the
bucks to have the headtube re-faced.



A Chris King headset is very picky in regard to the squarness of
everything including the stem. Did you face your stem, most people don't?

Lou
  #4  
Old November 7th 08, 07:10 PM posted to rec.bicycles.tech
[email protected]
external usenet poster
 
Posts: 3,751
Default Perpetually loosening threadless headset...

Dave Benoff wrote:

I have a Santa Cruz Blur mountain bike with a Chris King threadless
headset. In order to keep the headset from creaking due to fore/aft
movement, I have to re-tighten it every ~10 hours of ride time. I
am confident that the fore/aft movement is from the headset and not
the fork bushings (Rock Shox Reba fork w/alloy steerer) because the
noise disappears after re-tightening. The top cap has ample
clearance over the top of the steerer so its not bottoming, and the
stem has plenty of clamp area, although I run the stem with no
spacers above, so the clamp extends over the top of the steerer. I
bought the bike used in pristine condition so I very much doubt
there's any crash damage.


The headset cups appear to be seated properly. The only cause I can
think of is a poorly faced headtube or misaligned crown race. I was
told that a good test is to disconnect the front brake, remove the
handlebars, and rotate the stem 360 degrees, feeling for variations
in resistance due to misalignment. I did this and could not detect
any variation.


Can anyone advise as to whether the test outlined above is a
reliable way to check for misalignment? Any other hints for
troubleshooting this?


If it is loosening, then the stem clamp, that holds the whole thing
together and in the same place, must not be clamping properly. Is it
possible that the clamp is bottoming... that there is no gap in the
clamp slot when tightened?

I'd prefer to exhaust all my other options before shelling out the
bucks to have the headtube re-faced.


The way you report it, something is loose and moving.

Jobst Brandt
  #5  
Old November 7th 08, 07:50 PM posted to rec.bicycles.tech
sergio
external usenet poster
 
Posts: 504
Default Perpetually loosening threadless headset...

On 7 Nov, 18:22, Dave wrote:
I'd prefer to exhaust all my other options before shelling out the
bucks to have the headtube re-faced.


Just curious.
How much, over the Atlantic Pond, would a mechanic charge for
disassembling, facing and reassembling the set?

Sergio
Pisa
  #6  
Old November 7th 08, 07:56 PM posted to rec.bicycles.tech
Dave
external usenet poster
 
Posts: 78
Default Perpetually loosening threadless headset...

On Nov 7, 10:10*am, wrote:
If it is loosening, then the stem clamp, that holds the whole thing
together and in the same place, must not be clamping properly. *Is it
possible that the clamp is bottoming...


The clamp is not bottoming, and the behavior has occurred while using
a different stem as well.

My understanding is that the fore-aft motion of the steerer will
eventually cause any stem to migrate upward, no matter how well
fastened. I have no idea whether this is true, but it seems to be the
conventional wisdom, and certainly seems to be confirmed by my
experience.
  #7  
Old November 7th 08, 08:03 PM posted to rec.bicycles.tech
Dave
external usenet poster
 
Posts: 78
Default Perpetually loosening threadless headset...

On Nov 7, 10:50*am, sergio wrote:
On 7 Nov, 18:22, Dave wrote:

I'd prefer to exhaust all my other options before shelling out the
bucks to have the headtube re-faced.


Just curious.
How much, over the Atlantic Pond, would a mechanic charge for
disassembling, facing and reassembling the set?

Sergio
Pisa


Probably upwards of $100USD here in Los Angeles (probably cheaper in
other regions of the US). Many shops here don't even have the tools
or a mechanic skilled enough to do the work.
  #8  
Old November 7th 08, 08:05 PM posted to rec.bicycles.tech
[email protected]
external usenet poster
 
Posts: 1,299
Default Perpetually loosening threadless headset...

On Nov 7, 12:22*pm, Dave wrote:
I have a Santa Cruz Blur mountain bike with a Chris King threadless
headset. *In order to keep the headset from creaking due to fore/aft
movement, I have to retighten it every ~10 hours of ride time. *I am
confident that the fore/aft movement is from the headset and not the
fork bushings (Rock Shox Reba fork w/alloy steerer) because the noise
disappears after retightening. *The top cap has ample clearance over
the top of the steerer so its not bottoming, and the stem has plenty
of clamp area, although I run the stem with no spacers above, so the
clamp extends over the top of the steerer. *I bought the bike used in
pristine condition so I very much doubt there's any crash damage.

The headset cups appear to be seated properly. *The only cause I can
think of is a poorly faced headtube or misaligned crown race. *I was
told that a good test is to disconnect the front brake, remove the
handlebars, and rotate the stem 360 degrees, feeling for variations in
resistance due to misalignment. *I did this and could not detect any
variation.

Can anyone advise as to whether the test outlined above is a reliable
way to check for misalignment? *Any other hints for troubleshooting
this?

I'd prefer to exhaust all my other options before shelling out the
bucks to have the headtube re-faced.


I've experienced something similar twice. Doesn't seem like either is
the case for you, but I’ll relate the causes anyway.

The first time, it was a new headset that didn't have the cups pressed
into the frame tight enough. After a couple rounds of tightening the
stem, I really clamped the cups in there and the issue never came
back.

The second was recent. On a used bike, the steerer was too long for
the setup. It looked like there was ample clearance between the top
of the steerer and the cap, but was actually close enough to the cap
that the tightening of the star nut bottomed out the steerer to the
cap, even though there was clearance when not torqued down on the star
nut. I ended up trimming the steerer, but a spacer would have fixed
it as well.

How much room is there between the top of the steerer and the top of
the stem when inspecting? Are you 100% sure there is no way that it
is bottoming out? You could check by tightening everything up as
normal, then removing the cap. If there isn’t still some clearance at
the top of the steerer after you’ve torqued the cap against the star
and then tightened the stem, that could be your culprit.
  #9  
Old November 8th 08, 01:03 AM posted to rec.bicycles.tech
Anthony DeLorenzo
external usenet poster
 
Posts: 135
Default Perpetually loosening threadless headset...

On Nov 7, 9:22*am, Dave wrote:
I have a Santa Cruz Blur mountain bike with a Chris King threadless
headset. *In order to keep the headset from creaking due to fore/aft
movement, I have to retighten it every ~10 hours of ride time.


Maybe a long shot, but have you checked that the headtube is round and
not ovalized?
  #10  
Old November 8th 08, 02:29 AM posted to rec.bicycles.tech
jim beam
external usenet poster
 
Posts: 5,758
Default Perpetually loosening threadless headset...

On Fri, 07 Nov 2008 11:05:19 -0800, wrote:

On Nov 7, 12:22Â*pm, Dave wrote:
I have a Santa Cruz Blur mountain bike with a Chris King threadless
headset. Â*In order to keep the headset from creaking due to fore/aft
movement, I have to retighten it every ~10 hours of ride time. Â*I am
confident that the fore/aft movement is from the headset and not the
fork bushings (Rock Shox Reba fork w/alloy steerer) because the noise
disappears after retightening. Â*The top cap has ample clearance over
the top of the steerer so its not bottoming, and the stem has plenty of
clamp area, although I run the stem with no spacers above, so the clamp
extends over the top of the steerer. Â*I bought the bike used in
pristine condition so I very much doubt there's any crash damage.

The headset cups appear to be seated properly. Â*The only cause I can
think of is a poorly faced headtube or misaligned crown race. Â*I was
told that a good test is to disconnect the front brake, remove the
handlebars, and rotate the stem 360 degrees, feeling for variations in
resistance due to misalignment. Â*I did this and could not detect any
variation.

Can anyone advise as to whether the test outlined above is a reliable
way to check for misalignment? Â*Any other hints for troubleshooting
this?

I'd prefer to exhaust all my other options before shelling out the
bucks to have the headtube re-faced.


I've experienced something similar twice. Doesn't seem like either is
the case for you, but I’ll relate the causes anyway.

The first time, it was a new headset that didn't have the cups pressed
into the frame tight enough. After a couple rounds of tightening the
stem, I really clamped the cups in there and the issue never came back.

The second was recent. On a used bike, the steerer was too long for the
setup. It looked like there was ample clearance between the top of the
steerer and the cap, but was actually close enough to the cap that the
tightening of the star nut bottomed out the steerer to the cap, even
though there was clearance when not torqued down on the star nut. I
ended up trimming the steerer, but a spacer would have fixed it as well.

How much room is there between the top of the steerer and the top of the
stem when inspecting? Are you 100% sure there is no way that it is
bottoming out? You could check by tightening everything up as normal,
then removing the cap. If there isn’t still some clearance at the top
of the steerer after you’ve torqued the cap against the star and then
tightened the stem, that could be your culprit.



what he said.
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
threadless headset Steve Techniques 3 February 9th 07 04:11 AM
Loosening headset kirgudu Techniques 4 June 25th 06 10:15 PM
Threadless headset again.... David E. Belcher UK 1 November 22nd 04 07:31 PM
WTB: Threadless Headset, 1" Paul Kopit Marketplace 1 May 18th 04 02:50 PM
WTB: 1" threadless headset Mack Mad Marketplace 2 September 9th 03 02:36 PM


All times are GMT +1. The time now is 07:39 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 CycleBanter.com.
The comments are property of their posters.