2008 Giant TCR Headset Check
#1
I pedal in my sleep...
Thread Starter
2008 Giant TCR Headset Check
Just replaced a headset on a bike I've owned since 2012 but has been on the road for only about four years early on. The new headset was a Giant stock (FSA) bought from Giantbikespares.com and matches all part numbers for this model year TCR. The headset I removed did not exactly match with spacers, and bearing design, but the sizes and overall widths of the bearing/cup washers matched up. I'm getting a bit more gap between the fork and head tube. Replaced all parts with new according to the FSA diagram here:
This is the gap I now have:
Basically I can see the crown race where I couldn't before. But according to the diagram, I have done everything correctly. Double checked inside the head tube and no random parts were left. Measured all the bearings, spacers, compression rings, etc. and all matched what came out. The headset feels smooth and tight, operates as it should. Picture of the top for reference:
What am I missing here?
This is the gap I now have:
Basically I can see the crown race where I couldn't before. But according to the diagram, I have done everything correctly. Double checked inside the head tube and no random parts were left. Measured all the bearings, spacers, compression rings, etc. and all matched what came out. The headset feels smooth and tight, operates as it should. Picture of the top for reference:
What am I missing here?
#2
mechanically sound
Not sure what could cause that gap to increase, but I would just ride it as is. If something didn’t seat thoroughly, it will become evident and can then be easily addressed.
__________________
#3
I'm good to go!
Join Date: Jul 2017
Location: Mississippi
Posts: 14,984
Bikes: Tarmac Disc Comp Di2 - 2020
Mentioned: 51 Post(s)
Tagged: 0 Thread(s)
Quoted: 6191 Post(s)
Liked 4,807 Times
in
3,316 Posts
And there is no abnormal play? Straddle the bike on sidewalk or surface that has good tire grip. Lock the front brake and then push forward on the frame, not the handlebars, and then backwards. Does the headtube of the frame move differently than the steerer tube, spacers and other stuff? If so, you need to loosen the stems pinch bolts, then snug down the bolt going to the expanion plug or star nut and then retighten the stem bolts.
Otherwise I agree with frankenmike It'll eventually show you exactly what the issue is. And likely not in the disastrous way you might imagine or even more expensive than anything you might do towards it now.
Otherwise I agree with frankenmike It'll eventually show you exactly what the issue is. And likely not in the disastrous way you might imagine or even more expensive than anything you might do towards it now.
#4
I pedal in my sleep...
Thread Starter
And there is no abnormal play? Straddle the bike on sidewalk or surface that has good tire grip. Lock the front brake and then push forward on the frame, not the handlebars, and then backwards. Does the headtube of the frame move differently than the steerer tube, spacers and other stuff? If so, you need to loosen the stems pinch bolts, then snug down the bolt going to the expanion plug or star nut and then retighten the stem bolts.
Otherwise I agree with frankenmike It'll eventually show you exactly what the issue is. And likely not in the disastrous way you might imagine or even more expensive than anything you might do towards it now.
Otherwise I agree with frankenmike It'll eventually show you exactly what the issue is. And likely not in the disastrous way you might imagine or even more expensive than anything you might do towards it now.
#5
Senior Member
Join Date: Jul 2005
Location: Boulder County, CO
Posts: 4,393
Bikes: '80 Masi Gran Criterium, '12 Trek Madone, early '60s Frejus track
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 513 Post(s)
Liked 448 Times
in
337 Posts
Did the original headset have seat caps? I replaced the headset on a slightly older TCR, and the bearing seat was an integral part of the frame, so the bearings dropped in without caps. Take another look. If the frame bearing seat isn't beveled, you should use the caps that are designed to drop into a square seat. If they're beveled, the cap won't seat properly.
Last edited by oldbobcat; 08-15-22 at 11:03 AM.
#6
I pedal in my sleep...
Thread Starter
Did the original headset have seat caps? I replaced the headset on a slightly older TCR, and the bearing seat was an integral part of the frame, so the bearings dropped in without caps. Take another look. If the frame bearing seat isn't beveled, you should use the caps that are designed to drop into a square seat. If they're beveled, the cap won't seat properly.
#7
Guest
Join Date: Sep 2020
Posts: 2,888
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 1346 Post(s)
Liked 3,270 Times
in
1,439 Posts
[QUOTE=str8jakett;22609052] The headset I removed did not exactly match with spacers, and bearing design [/QUOTE]
Was the original headset also FSA?
Was the original headset also FSA?
#8
I pedal in my sleep...
Thread Starter
[QUOTE=Rolla;22612218]There was no FSA marking on the headset I removed so I can't say for sure. No size or other markings on the bearings themselves either unless it had worn off. The overall measurements and size were exactly the same one bearings and seat cups were combined, but the seat cups wrapped the internal part of the old bearings more, if that makes any sense. The biggest noticeable difference was the dust cover/top cap that had no markings and was a bit flatter on the old headset and very unlike the FSA top cap that replaced it.
#9
Senior Member
Join Date: Jul 2005
Location: Boulder County, CO
Posts: 4,393
Bikes: '80 Masi Gran Criterium, '12 Trek Madone, early '60s Frejus track
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 513 Post(s)
Liked 448 Times
in
337 Posts
I'm thinking there might be a difference in how the new seat caps are seating. Have you tried using the new bearings with the old seat caps, after making sure bearing bevels match the cap bevels?
#10
I pedal in my sleep...
Thread Starter
It is possible the bearings aren't seating tightly. After 35 miles around town and through the park yesterday, I do have some new wobble in the headset, but a lot less than I would have expected. I admit I didn't have any time to inspect or pull things apart to find out if the old seat caps would work after the ride.
#11
Guest
Join Date: Sep 2020
Posts: 2,888
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 1346 Post(s)
Liked 3,270 Times
in
1,439 Posts
I wouldn't expect any wobble after a 35 mile ride, if things were copacetic. Something is up with the replacement parts, in spite of the measurements aligning; wish I could direct you towards what to look at; my best guess is the seat caps.
#12
Senior Member
Join Date: Jul 2005
Location: Boulder County, CO
Posts: 4,393
Bikes: '80 Masi Gran Criterium, '12 Trek Madone, early '60s Frejus track
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 513 Post(s)
Liked 448 Times
in
337 Posts
What Rolla said. Something is wiggling in there that shouldn't be.
#13
I pedal in my sleep...
Thread Starter
Appreciate all of your help and advice on the subject.