Threadless headset cleaning

hfidgen
hfidgen Posts: 340
edited May 2011 in The workshop
Hiya,

I've got a BMC CX02 with a threadless headset, and it's been making a few grinding noises due to road grit so I decided to clean it. Disassembling it all was easy, and I put the parts in order for reassembly, but then had to leave the house for a couple of hours.

On return, the parts were in a jumble either from kid or cat (kid most likely I guess) and tbh I'm not 100% sure how it goes back together now!

I've played with every combination and i think it's all OK, but there are two little bevelled pieces which fit around the bearings somehow which I'm not 100% sure on. Can anyone link me to a decent video tutorial? I've found this, but it's not totally clear.
http://www.youtube.com/watch?v=KS6lAwUtRx0

I'll post photos later for total clarity.
FCN 4 - BMC CX02

Comments

  • nicklouse
    nicklouse Posts: 50,675
    read the info on Parktools.

    Link below.

    if that does not help take a picture and number the parts.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • hfidgen
    hfidgen Posts: 340
    Here you go:

    1 - Head race, with cable guide on outside for front brakes
    2 - Bearing
    3 - Mystery 1
    4 - Mystery 2
    5 - Spacers
    6 - Cap with bolt.

    You'll see from photo 2 that the headset has a nice space for the bearing to slot into, and the head race then clamps over this, with a rubber seal for good measure (photo 3). Spacers on top, on with the bars and all looks hunky dorey.

    EXCEPT

    Those 2 mystery parts...

    You'll see from photo 4 that part 3 slots neatly into the bearing, acting to centre it on the steering shaft. (You can see it in there on photo 5)

    But as to where the hell part 4 goes I'm at a loss I'm afraid. I've tried just putting it on top of the bearing, and under the race, which works, but it doesn't seem right somehow, I'm concerned it's not supposed to go there.

    Any help much appreciated!

    all-bits.jpg

    headtube.jpg

    pressed_frame.jpg

    race-and-mystery2.jpg

    race-and-mystery1.jpg
    FCN 4 - BMC CX02
  • Blue Meanie
    Blue Meanie Posts: 495
    Assumptions:
    You know which way the bearing fit?
    You haven't removed the crown race from the top of the fork (crown)?

    I'd say 4 goes on top of the lower bearing and 3 goes on top of the upper bearing. Would be so much easier with the bike and bits in front of me. All looks nice and clean now though :)
    FCN16 - 1970 BSA Wayfarer

    FCN4 - Fixie Inc
  • hfidgen
    hfidgen Posts: 340
    Figured it out:

    - Bearing into frame casing, beveled end down.
    - Black part #3 into bearing, to centre it on steering shaft
    - Silver part #4 on top of this, tapered end UP
    - Top race clamps down, sitting over tapered end of #4, clamping it all into place
    - Spacers, lock nut etc etc

    Steering is smooth as can be, no noise and everything is solid as a rock :)

    final.jpg

    Have to say I'm impressed by the design - the bearings stay absolutely free to move, you can't overtighten them, and the rubber seals mean that it's actually very hard for grit and water to get in there. Should be a clean once every 6 months tbh.

    Thanks for the help.
    FCN 4 - BMC CX02

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