Crown race Goldilocks...
Results 1 to 9 of 9
  1. #1
    What the what???
    Reputation: Opus51569's Avatar
    Join Date
    Jul 2009
    Posts
    12,214

    Crown race Goldilocks...

    Trek 420 fork.

    Two crown races. One is 27.0 and goes on with no effort. One is 26.4 and I canít get it to seat with grease, a length of PVC and a sledge hammer.

    Do I keep trying to force the 26.4 or try dimpling the fork to make the 27.0 tight?


    Sent from my iPad using Tapatalk
    Given his penchant for nicknames, and his aversion to reading, I've decided to shorten Donald J. Trump to it's essence: Dump*

    I was "social distancing" before it was cool.

  2. #2
    RoadBikeReview Member
    Reputation:
    Join Date
    Dec 2006
    Posts
    4,259
    Don't dimple the fork.

    Can you measure the crown race with a vernier caliper?

    Does the 27.0 fit with slop, or is it a slip fit?

  3. #3
    What the what???
    Reputation: Opus51569's Avatar
    Join Date
    Jul 2009
    Posts
    12,214
    Just a tiny bit of play with just the race. I donít have a digital caliper but I do have an analog one. The fork measures just under 27. 26.8 or 9. So the smaller race (which is supposed to be 26.4 but measures closer to 26.2 is a no-go). Itís the 27.0 (which measures 27) or nothing.

    I decided to try putting the rest of the headset together using the 27.0 race. When I load the bearings and tighten everything up there is no play, though. But can I assume that with everything loaded itís the bearings that are turning and not the race?

    1 inch threaded Origin8 headset with sealed bearings.


    Sent from my iPhone using Tapatalk
    Last edited by Opus51569; 3 Weeks Ago at 07:16 AM.
    Given his penchant for nicknames, and his aversion to reading, I've decided to shorten Donald J. Trump to it's essence: Dump*

    I was "social distancing" before it was cool.

  4. #4
    RoadBikeReview Member
    Reputation:
    Join Date
    Dec 2006
    Posts
    4,259
    You can use Loctite to secure the crown race to the steerer, if the gap isn't too large. I think it's the Green Loctite, although I forget which number.

    Is the fork new? sounds like it wasn't machined. Personally, I'd take it to a bike shop and have them cut the fork crown race for 26.4 as it's a more common size. 27.0 was used on Campy headsets, I believe.

  5. #5
    RoadBikeReview Member
    Reputation: velodog's Avatar
    Join Date
    Sep 2007
    Posts
    8,423
    https://sheldonbrown.com/cribsheet-headsets.html

    I like Peter P's plan on getting it cut to 26.4.

    Question...

    Did you mask the crown race seat on the fork when you painted the fork? Are you measuring a bare crown race seat or a painted one? It could be a proper 26.4 with paint built up to 27.
    Too old to ride plastic

  6. #6
    RoadBikeReview Member
    Reputation: velodog's Avatar
    Join Date
    Sep 2007
    Posts
    8,423
    Another question, what was the dimension of the headset crown race that was original to the fork?
    Too old to ride plastic

  7. #7
    What the what???
    Reputation: Opus51569's Avatar
    Join Date
    Jul 2009
    Posts
    12,214

    Crown race Goldilocks...

    Quote Originally Posted by velodog View Post
    https://sheldonbrown.com/cribsheet-headsets.html

    I like Peter P's plan on getting it cut to 26.4.

    Question...

    Did you mask the crown race seat on the fork when you painted the fork? Are you measuring a bare crown race seat or a painted one? It could be a proper 26.4 with paint built up to 27.
    Yep. I masked the crown when I painted. Iím measuring bare metal. The fork is from 1983, Peter P. I think it was a year when Trek farmed their frames out to an Asian manufacturer.

    Good call about the race that was on it. Iíll have to see how if I still have it. I know in taking it off it took some leverage. It wasnít loose.

    I may try the loctite fix, but I donít think I mess with having it machined.


    Sent from my iPad using Tapatalk
    Last edited by Opus51569; 3 Weeks Ago at 03:13 PM.
    Given his penchant for nicknames, and his aversion to reading, I've decided to shorten Donald J. Trump to it's essence: Dump*

    I was "social distancing" before it was cool.

  8. #8
    RoadBikeReview Member
    Reputation:
    Join Date
    Dec 2006
    Posts
    4,259
    If you want to secure that 27.0 to the crown race, use Loctite 660. It's a liquid retaining compound that fills gaps up to 0.5mm. Comes in a very small tube.

    I would apply the 660 then immediately assemble the fork to the frame, as a guide to center the fork crown race within the lower cup. That's key to good headset operation and long bearing life.

  9. #9
    RoadBikeReview Member
    Reputation:
    Join Date
    Feb 2002
    Posts
    21,345
    Quote Originally Posted by Opus51569 View Post
    Trek 420 fork.

    Two crown races. One is 27.0 and goes on with no effort. One is 26.4 and I canít get it to seat with grease, a length of PVC and a sledge hammer.

    Do I keep trying to force the 26.4 or try dimpling the fork to make the 27.0 tight?
    Back in the day many bike shops had a crown race seat tool so you could chase the crown race seat to the right size. It sounds like this is what you need to do. Find a shop that has the proper tool.

Similar Threads

  1. crown race spins around on fork crown
    By blackfrancois in forum Components, Wrenching
    Replies: 25
    Last Post: 11-25-2018, 03:31 PM
  2. Looking for the "goldilocks" saddle
    By dgeesaman in forum General Cycling Discussion
    Replies: 16
    Last Post: 05-30-2017, 06:17 PM
  3. Specialized and the Goldilocks Principle
    By ukbloke in forum Specialized
    Replies: 8
    Last Post: 09-10-2011, 03:20 PM
  4. Recommend Goldilocks shoes -- not road, not MTB?
    By since17 in forum General Cycling Discussion
    Replies: 9
    Last Post: 09-04-2008, 10:11 AM
  5. Goldilocks and Saddles- Is Brooks just right?
    By Bernadette Lopes in forum General Cycling Discussion
    Replies: 8
    Last Post: 04-10-2006, 05:54 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

THE SITE

ABOUT ROADBIKEREVIEW

VISIT US AT

© Copyright 2020 VerticalScope Inc. All rights reserved.