Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

2008 Giant TCR Headset Check

Notices
Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

2008 Giant TCR Headset Check

Old 08-13-22, 01:36 PM
  #1  
str8jakett
I pedal in my sleep...
Thread Starter
 
str8jakett's Avatar
 
Join Date: Jun 2009
Location: Radford VA
Posts: 626

Bikes: Giant TCR Advanced 2015, Giant Propel Advanced Pro 2015, Giant TCR Advanced 0 ISP 2008, Cube Cross Race SL 2018

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 127 Post(s)
Liked 59 Times in 32 Posts
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?
str8jakett is offline  
Old 08-14-22, 11:11 AM
  #2  
frankenmike 
mechanically sound
 
frankenmike's Avatar
 
Join Date: Jan 2007
Location: Dover, NH
Posts: 1,581

Bikes: Indy Fab steel deluxe, Aventon cordoba, S-works stumpy fsr, Masi vincere, Dahon mu uno, Outcast 29 commuter

Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 78 Post(s)
Liked 50 Times in 38 Posts
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.
__________________
frankenmike is offline  
Old 08-14-22, 12:28 PM
  #3  
Iride01 
MotuekaCascadeChinook
 
Iride01's Avatar
 
Join Date: Jul 2017
Location: Mississippi
Posts: 11,465

Bikes: Tarmac Disc Comp Di2 - 2020

Mentioned: 43 Post(s)
Tagged: 0 Thread(s)
Quoted: 4658 Post(s)
Liked 3,156 Times in 2,198 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.
Iride01 is offline  
Old 08-15-22, 03:35 AM
  #4  
str8jakett
I pedal in my sleep...
Thread Starter
 
str8jakett's Avatar
 
Join Date: Jun 2009
Location: Radford VA
Posts: 626

Bikes: Giant TCR Advanced 2015, Giant Propel Advanced Pro 2015, Giant TCR Advanced 0 ISP 2008, Cube Cross Race SL 2018

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 127 Post(s)
Liked 59 Times in 32 Posts
Originally Posted by frankenmike View Post
Not sure what could cause that gap to increase, but I would just ride it as is. If something didnít seat thoroughly, it will become evident and can then be easily addressed.
Originally Posted by Iride01 View Post
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.
No play at all and really, it works exactly as I would have expected after replacing a well worn out set of bearings. I'll give it a test ride through the neighborhood before venturing too far away and see if anything changes or seats more properly. Thanks for the advice!
str8jakett is offline  
Old 08-15-22, 10:54 AM
  #5  
oldbobcat
Senior Member
 
oldbobcat's Avatar
 
Join Date: Jul 2005
Location: Boulder County, CO
Posts: 3,586

Bikes: '79 Gios, '80 Masi, '06 Felt, early '60s Frejus

Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 207 Post(s)
Liked 179 Times in 133 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.
oldbobcat is offline  
Old 08-16-22, 07:15 AM
  #6  
str8jakett
I pedal in my sleep...
Thread Starter
 
str8jakett's Avatar
 
Join Date: Jun 2009
Location: Radford VA
Posts: 626

Bikes: Giant TCR Advanced 2015, Giant Propel Advanced Pro 2015, Giant TCR Advanced 0 ISP 2008, Cube Cross Race SL 2018

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 127 Post(s)
Liked 59 Times in 32 Posts
Originally Posted by oldbobcat View Post
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.
Good question, but yes the previous headset had seat caps. I matched up the old bearing + seat cap with the new bearing + seat cap to compare the overall height and all had matched.
str8jakett is offline  
Old 08-16-22, 09:00 AM
  #7  
Rolla
Former Member
 
Join Date: Sep 2020
Posts: 2,572
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 1156 Post(s)
Liked 2,841 Times in 1,253 Posts
[QUOTE=str8jakett;22609052] The headset I removed did not exactly match with spacers, and bearing design [/QUOTE]

Was the original headset also FSA?
Rolla is offline  
Old 08-16-22, 09:12 AM
  #8  
str8jakett
I pedal in my sleep...
Thread Starter
 
str8jakett's Avatar
 
Join Date: Jun 2009
Location: Radford VA
Posts: 626

Bikes: Giant TCR Advanced 2015, Giant Propel Advanced Pro 2015, Giant TCR Advanced 0 ISP 2008, Cube Cross Race SL 2018

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 127 Post(s)
Liked 59 Times in 32 Posts
[QUOTE=Rolla;22612218]
Originally Posted by str8jakett View Post
The headset I removed did not exactly match with spacers, and bearing design [/QUOTE]

Was the original headset also FSA? Something isn't matching up; the specs of replacement parts for this model might not be identical to the original.
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.
str8jakett is offline  
Old 08-16-22, 04:11 PM
  #9  
oldbobcat
Senior Member
 
oldbobcat's Avatar
 
Join Date: Jul 2005
Location: Boulder County, CO
Posts: 3,586

Bikes: '79 Gios, '80 Masi, '06 Felt, early '60s Frejus

Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 207 Post(s)
Liked 179 Times in 133 Posts
Originally Posted by str8jakett View Post
Good question, but yes the previous headset had seat caps. I matched up the old bearing + seat cap with the new bearing + seat cap to compare the overall height and all had matched.
So the stack heights of the new bearings plus seat caps matches the stack heights of the old bearings plus seat caps, but the new bearings still extend farther out from the head tube. This is weird.

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?
oldbobcat is offline  
Old 08-17-22, 03:31 AM
  #10  
str8jakett
I pedal in my sleep...
Thread Starter
 
str8jakett's Avatar
 
Join Date: Jun 2009
Location: Radford VA
Posts: 626

Bikes: Giant TCR Advanced 2015, Giant Propel Advanced Pro 2015, Giant TCR Advanced 0 ISP 2008, Cube Cross Race SL 2018

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 127 Post(s)
Liked 59 Times in 32 Posts
Originally Posted by oldbobcat View Post
So the stack heights of the new bearings plus seat caps matches the stack heights of the old bearings plus seat caps, but the new bearings still extend farther out from the head tube. This is weird.
Yes, this is what I'm saying, the dimensions are the same.

Originally Posted by oldbobcat View Post
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?
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.
str8jakett is offline  
Old 08-17-22, 11:56 AM
  #11  
Rolla
Former Member
 
Join Date: Sep 2020
Posts: 2,572
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 1156 Post(s)
Liked 2,841 Times in 1,253 Posts
Originally Posted by str8jakett View Post
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 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.
Rolla is offline  
Old 08-18-22, 04:01 PM
  #12  
oldbobcat
Senior Member
 
oldbobcat's Avatar
 
Join Date: Jul 2005
Location: Boulder County, CO
Posts: 3,586

Bikes: '79 Gios, '80 Masi, '06 Felt, early '60s Frejus

Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 207 Post(s)
Liked 179 Times in 133 Posts
What Rolla said. Something is wiggling in there that shouldn't be.
oldbobcat is offline  
Old 08-22-22, 08:45 AM
  #13  
str8jakett
I pedal in my sleep...
Thread Starter
 
str8jakett's Avatar
 
Join Date: Jun 2009
Location: Radford VA
Posts: 626

Bikes: Giant TCR Advanced 2015, Giant Propel Advanced Pro 2015, Giant TCR Advanced 0 ISP 2008, Cube Cross Race SL 2018

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 127 Post(s)
Liked 59 Times in 32 Posts
Originally Posted by Rolla View Post
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.
Originally Posted by oldbobcat View Post
What Rolla said. Something is wiggling in there that shouldn't be.
I've had no time to deal with this until yesterday. I pulled the headset apart, compared it to the old headset once again just to verify it really did match up with the specifications. The seat cap from the bottom bearing matches and could be swapped between old and new bearings. The old seat cap for the upper bearing is slightly different in design to wrap around the bearing more, but still matches dimensions. I replaced the new bearings and seat caps, added a spacer under the stem, and swapped out the compression plug for one I felt would protect better and have a more typical top cap (cap+bolt rather than cap being tightened to the compression plug). Once everything was back together, the gaps remained, but everything was tight once again. I left it alone as the bike was going back on the trainer anyway. I've got enough maintenance to keep up with on the bikes I actually ride outdoors without adding another into the mix anyway.

Appreciate all of your help and advice on the subject.
str8jakett is offline  

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

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.