Results 1 to 10 of 10
  1. #1
    FJP
    FJP is offline
    mtbr member
    Reputation:
    Join Date
    Jun 2015
    Posts
    16

    Beer can shim on lower headset cup

    Hi there,

    I am building up a second hand full suspension frame (2005 Rocky Mountain Element Team SC).

    Yesterday I removed the old headset with a removal tool and installed my new headset with a DIY headset press. The top cup is pressed perfectly with a tight fit, but the bottom one I can push it in and pull it out by hand and I am able to turn it around.

    I am reading about shimming it with a beer can or alike. So now I am wondering if it safe to ride while bottom cup is shimmed regarding all the forces that come in to place while riding, braking an jumping?

    I can still try to use the old lower if that would be better.

    Thanks in advance!

    Sent from my Mars pro using Tapatalk

  2. #2
    mtbr member
    Reputation:
    Join Date
    Mar 2015
    Posts
    458
    Bitd I rode a bmx shimmed like that for a couple of years with no problems at all!
    Kes
    Last edited by fxrextreme; 12-22-2017 at 04:17 AM. Reason: Spelling mistake

  3. #3
    mtbr member
    Reputation: Mr Pig's Avatar
    Join Date
    Jun 2008
    Posts
    10,507
    I can't see it causing any problems. If it's not tight the shim might move and wear away to nothing but as long as you keep an eye on it I'm sure it will be fine.

  4. #4
    Plays with tools
    Reputation: customfab's Avatar
    Join Date
    Jun 2008
    Posts
    4,583
    Loctite 680 is made for applications like this. Clean both surfaces with acetone and apply a liberal amount in the headtube and slide the cup in, let it sit overnight and you'll never have to worry about it again. Should you need to remove it heating it up to ~250* will let it slide right back out again. I've been riding a road bike with this fix for several years and it's been flawless.

  5. #5
    mtbr member
    Reputation:
    Join Date
    Jan 2006
    Posts
    811
    I agree with customfab, been riding a chinese hartdail fixed like that for 3 years, and still ridden hard by second owner...
    flyMTBfish

  6. #6
    mtbr member
    Reputation: Mr Pig's Avatar
    Join Date
    Jun 2008
    Posts
    10,507
    I'd look at it and consider either method. The main thing is that it must end up tight. As long as that cup stays put you're golden.

  7. #7
    Plays with tools
    Reputation: customfab's Avatar
    Join Date
    Jun 2008
    Posts
    4,583
    Quote Originally Posted by Mr Pig View Post
    I'd look at it and consider either method. The main thing is that it must end up tight. As long as that cup stays put you're golden.
    This is where 5 minutes with a respectable set of calipers can guide you in the right direction. The difference between a bearing pressing in or sliding in is about .002". If the headtube is .005" or less over you're better off with bearing retainer. If it's more than .005" over sized then a beer can shim can work as well. The problem is putting a shim where there's not room for one. This can stress the headset cup, head tube or cause misalignment that will lead to poor bearing durability. Bearing retainer will run you less than a 6 pack and is a more reliable long term fix IMPO.

  8. #8
    Class Clown
    Reputation: dundundata's Avatar
    Join Date
    May 2009
    Posts
    2,384
    sounds pretty shim sham

    the real question is which brew to choose?

  9. #9
    FJP
    FJP is offline
    mtbr member
    Reputation:
    Join Date
    Jun 2015
    Posts
    16
    Quote Originally Posted by dundundata View Post
    sounds pretty shim sham

    the real question is which brew to choose?
    Thanks. For now I used the original cup at the bottom and the new one at the top. Both have a snug fit. I am waiting for the replacement lower part of the new cup to try out. I have a feeler measurement gauge set with different sizes to use as a shim. Maybe I will try that out in a while.

    Sent from my Mars pro using Tapatalk

  10. #10
    mtbr member
    Reputation: One Pivot's Avatar
    Join Date
    Nov 2009
    Posts
    7,945
    It sounds like your new headset is undersized, the headtube might be ok.

Similar Threads

  1. Replies: 25
    Last Post: 05-04-2017, 08:43 PM
  2. To shim or not to shim seatpost?
    By kneetowaist in forum All Mountain
    Replies: 16
    Last Post: 09-20-2015, 07:03 PM
  3. Need a lower headset cup for a tapered fork
    By epoch2k in forum 29er Components
    Replies: 3
    Last Post: 04-15-2012, 06:55 PM
  4. Hope Headset - Lower cup question
    By OldHouseMan in forum 29er Components
    Replies: 0
    Last Post: 01-29-2012, 11:29 PM
  5. Fix For Loose Lower Headset Cup
    By JJY in forum Frame Building
    Replies: 2
    Last Post: 09-26-2011, 11:09 AM

Members who have read this thread: 1

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 MTBR

VISIT US AT

© Copyright 2019 VerticalScope Inc. All rights reserved.