Road Bike, Cycling Forums banner
1 - 15 of 15 Posts

·
Registered
Joined
·
2,372 Posts
Discussion Starter · #1 ·
December maintenance, I disassembled the bike and re-greased and cleaned it up. Since then, the threaded headset keeps loosening up. I've done this routine each winter and thensome over 20 years so it's not the first time. It is the first time, I have not been able to keep it snug. Invariably somewhere at 30-50 miles of road time, the top nut has backed off so the threaded bearing race vibrates loose too.

This is a well aged Shimano 600EX headset. I cannot figure what is slipping. The only suspect is this top nut the threads do not seem as deeply cut as the prior 600 EX headset. BUT it had been in use for some 2000 miles. This last maintenance session just has it ???

Help...
 

·
Registered
Joined
·
21,636 Posts
Spacer?

Kuma601 said:
December maintenance, I disassembled the bike and re-greased and cleaned it up. Since then, the threaded headset keeps loosening up. I've done this routine each winter and thensome over 20 years so it's not the first time. It is the first time, I have not been able to keep it snug. Invariably somewhere at 30-50 miles of road time, the top nut has backed off so the threaded bearing race vibrates loose too.

This is a well aged Shimano 600EX headset. I cannot figure what is slipping. The only suspect is this top nut the threads do not seem as deeply cut as the prior 600 EX headset. BUT it had been in use for some 2000 miles. This last maintenance session just has it ???
The first suspect for me would be that the top nut is bottoming out against the end of the steerer tube, preventing you from getting full force between the upper cup and the lock nut. Try adding another thin spacer (washer) above the adjustable cup. Just a thought.

Also, with time it could be that your threads are just getting loose from wear, and that might be an issue.
 

·
Premium Member
Joined
·
20,473 Posts
Kerry Irons said:
The first suspect for me would be that the top nut is bottoming out against the end of the steerer tube, preventing you from getting full force between the upper cup and the lock nut. Try adding another thin spacer (washer) above the adjustable cup. Just a thought.

Also, with time it could be that your threads are just getting loose from wear, and that might be an issue.
I agree with Kerry.. another thing to check is does the steerer tube have a flat spot and did you install the spacer/washer with the notch?
 

·
Registered
Joined
·
2,372 Posts
Discussion Starter · #4 ·
Thanks guys!

The aluminum top nut I suspect is the culprit, the threads seem shallower and this last time I even used a thread locker. Obviously failed. It does have the notched spacer installed.

I began but stopped installing the Campy Record HS. The fork crown race measures out to be about 26.40mm, the Shimano lower race fits perfectly...snug but a simple tap with a collet seats it. The Campy measures out to 26.36mm. It does not want to go on nicely and hammering at it seems crude. Advice on getting it to fit?

I thought about having it lathed to the fork but this seems more trouble for what should be an easier install. I dunno how precise this part needs to be fitted so taking sandpaper seemed crude also.

??
 

·
duh...
Joined
·
9,658 Posts
Kuma601 said:
Thanks guys!

The aluminum top nut I suspect is the culprit, the threads seem shallower and this last time I even used a thread locker. Obviously failed. It does have the notched spacer installed.

I began but stopped installing the Campy Record HS. The fork crown race measures out to be about 26.40mm, the Shimano lower race fits perfectly...snug but a simple tap with a collet seats it. The Campy measures out to 26.36mm. It does not want to go on nicely and hammering at it seems crude. Advice on getting it to fit?

I thought about having it lathed to the fork but this seems more trouble for what should be an easier install. I dunno how precise this part needs to be fitted so taking sandpaper seemed crude also.

??


crowns race are typically bashed on... it's pretty much what you do with a proper a race setting tool
 

·
Registered
Joined
·
21,636 Posts
Significant figures

Kuma601 said:
The fork crown race measures out to be about 26.40mm, the Shimano lower race fits perfectly...snug but a simple tap with a collet seats it. The Campy measures out to 26.36mm. It does not want to go on nicely and hammering at it seems crude. Advice on getting it to fit?
For this application, 26.40 and 26.36 are the same number. You want some friction as the crown race is installed. Use plenty of grease and use your setting tool to drive it home. No worries.
 

·
Registered
Joined
·
2,372 Posts
Discussion Starter · #7 ·
Done. Thanks guys!

I opened it up to inspect and discovered the few knocks had brinelled the lower cup. Not much but enough to leave a faint impression. :( With it apart, the Record HS went in. It snugged up much nicer so it was likely thread wear.

I was amazed looking at Universal Cycles headsets, the Campy Record is listed at $100 now. If anything happens, a King is going in there.
 

·
duh...
Joined
·
9,658 Posts
Kuma601 said:
Done. Thanks guys!

I opened it up to inspect and discovered the few knocks had brinelled the lower cup. Not much but enough to leave a faint impression. :( With it apart, the Record HS went in. It snugged up much nicer so it was likely thread wear.

I was amazed looking at Universal Cycles headsets, the Campy Record is listed at $100 now. If anything happens, a King is going in there.


the gripnut is really nice... imo, has a more classic look- due to the topnut- than the newer records
 

·
Registered
Joined
·
797 Posts
Worn threads? Permatex is your freind!
 

·
Registered
Joined
·
2,372 Posts
Discussion Starter · #10 ·
I had used a thread sealant twice. I was thinking rounded threads or maybe some cross threading, nope...clean. Threading on the top cap and nut from the Record HS was night-day.

My guess is the stray grit that weaseled onto the threads after all the seasons had taken a toll on the aluminum. This past tear down was the last one to open the tolerances up enough that it wouldn't hold anymore. My lesson from this, I won't open the HS up annually but leave it if all else looks and feels good.

I wondered how durable aluminum threads would be.(?) This is one interface area a threadless HS has some advantages..me thinks.
 

·
Registered
Joined
·
21,636 Posts
Aluminum top nut durability

Kuma601 said:
My lesson from this, I won't open the HS up annually but leave it if all else looks and feels good.

I wondered how durable aluminum threads would be.(?) This is one interface area a threadless HS has some advantages..me thinks.
I have used Al top nut threaded headsets for over a decade, and well over 60,000 miles with no noticeable deterioration in the threads. I do a complete tear down of my bike every year, and I think that "leave it alone if all else looks and feels good" is a bad approach to take in bicycle maintenance.
 

·
Registered
Joined
·
2,372 Posts
Discussion Starter · #12 ·
You're right...leaving it would not be smart. What is the thought on Campys white grease?
I'm accustomed to using a heavier synthetic grease and the Campy stuff felt "thin".
 

·
Registered
Joined
·
21,636 Posts
Grease choice

Kuma601 said:
=What is the thought on Campys white grease? I'm accustomed to using a heavier synthetic grease and the Campy stuff felt "thin".
Campy white grease is for rolling bearings. Their brown grease is for things like headsets and threads. Not that it makes a lot of difference. Any good grease is just fine.
 

·
Unsafe at Any Speed
Joined
·
456 Posts
Definitely use a lock washer. A one-turn helix type. It might be hard to find but a non-cycling fastener outfit should stock a suitable size.
 

·
Registered
Joined
·
2,372 Posts
Discussion Starter · #15 ·
Interesting...could probably make one from an old washer depending on material composition. The bandsaw or hacksaw would leave a wide kerf but using a jewelers wire saw would be pretty thin. Hmm...I'll tuck that away for reference, thanks for the idea.
 
1 - 15 of 15 Posts
Top