Results 1 to 1 of 1
  1. #1
    mtbr member
    Reputation:
    Join Date
    Jan 2010
    Posts
    33

    DHS Mono 2:1 swing arm main pivot bearing service

    Continuing with the strip down and rebuild of the frame i recently bought.
    Aside from finding out that the guy i bought it off is a mongrel and the frame bearings havnt been serviced in years...if ever...

    I am editing the first post i made as i have done some homework, bit the bullet, got down and physical and come up with a result; so the questions i set are now answered.
    I will post the results of the rebuild step by step and add photos for those of you who would like to try this and are feeling intimidated by the cost of failure, having not been blessed with the knowledge implanted in your DNA.

    The main pivot bearings are covered by what looks to be two black alloy covers. These are in fact stub axles carrying the swing arm and connecting it to the frame. they are about 39mm(1 1/2") long and 25mm (1") diameter behind the external face. And SOLID, neigh on unbreakable. They are both conventional threaded into a tube running through the main frame and unscrew anti clockwise.They have been loctited/threadlocked at the factory using a high strength product. There is no need to use heat to loosen it, it will yield-suddenly- when you have applied sufficient steady force. I used a 12" length of tube to extend the allen key and the threadlock yielded with still considerable effort so maybe 18" would be better. I would recommend you pull towards you resting the down tube or swing arm(depending on the side you are working on) against your chest to cushion it and avoid at all costs levering against the monocoque top tube: the alloy is too thin and will dent.
    The axles have a narrow O ring to seal the bearings from the outboard side. In board there is nothing but the frame isnt too exposed.

    The bearings:
    There are four in two sets of two with an alloy spacer in each set. The bearings are custom made by Enduro to their highest standard ( max) and are an unusual size. So far i have been unable to find an alternative but frankly the price quoted by the importer(Balfa)in the UK is very good compared to similar sized bearings of the same quality and includes a pair of spacers as a kit.
    I will be getting one to fit soon:
    On my frame the non drive side bearings are serviceable but showing the tinyest amount of roughness. On the drive side the outboard bearing is 100% OK the inner however is rough and must be responsible for the notchiness i felt in the swing arm movement.Only the drive side axle had an O ring fitted; i will be sourcing new for both sides.

    The swing link bearings are a common size: 6000 2RS. Again they are Enduro. The importer sells a kit of all 6 necessary together with the alloy "top hat" spacers which also act as covers to the rubber seals. The price of the kit is steep compared to top quality replacements and the spacers are OK so i will be replacing with SKF bearings. It is easy to find hybrid or full ceramic replacements if you wish, unlike the main pivot bearings.
    Of the three pairs in the swing link two are OK and one is seized, the connecting bolt was acting as the bearing. One of the connecting bolts is seized into the swing arm and the allen fitting has been rounded out so i will be removing it by carefully welding a nut to the head with a MIG welder. This is a technique my brother( fully qualified engineer)showed me for removing sheared studs in alloy castings. Works a treat even when the break is way below the surface BUT needs very careful, thoughtful application. Better than drilling out if you have the patience. Drilling usually results in the drill slipping and the alloy is much softer than the steel......NUF SAID!

    PIX and more to follow
    Last edited by karrikourier; 10-09-2011 at 07:33 PM. Reason: Progress made

Similar Threads

  1. 575 main pivot bearing removal?
    By VaughnA in forum Yeti
    Replies: 5
    Last Post: 01-21-2013, 11:39 AM
  2. 575 main pivot bearing and play
    By yeti rider in forum Yeti
    Replies: 2
    Last Post: 02-08-2010, 10:31 AM
  3. ML2 main pivot bearing life?
    By HOG farmer in forum Titus
    Replies: 4
    Last Post: 10-12-2008, 03:53 PM
  4. Main Pivot Bearing
    By smh151 in forum Titus
    Replies: 7
    Last Post: 12-14-2006, 03:10 PM
  5. NRS Main Swing arm pivot noise
    By jenlee in forum Giant
    Replies: 1
    Last Post: 06-11-2006, 07:13 PM

Posting Permissions

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