Fork gone pop

concorde
concorde Posts: 1,008
edited March 2017 in MTB workshop & tech
Hi,

Out riding today and my fork kinda went pop? Went over a small root, nothing major and certainly not fast. Felt a clunk as if fork had topped out. Pulled over and seemed to be very little air in them and no rebound damping whatsoever.

Rode to end of trail, very slowly and forks topped out few times on way and were running low in their travel so had lost air.

Any ideas what this could be? They're under warranty and have sent them off just wondering what and why it could happen?

Fox 34 Rhythms...

Cheers

Comments

  • supersonic
    supersonic Posts: 82,708
    Usually if only the air pressure in the positive chamber drops, the rebound feels like it has slowed down, as less force pushing the fork to its extended position. The damper and spring are in different legs - so if it has simultaneously lost pressure and damping then you are very unlucky! Though a knackered damper may give a feel that it has lost pressure as there would be nowhere near as much low speed support, propping the fork up as they are designed to.

    My guess is that the air shaft lower seal has gone. This would basically make the whole leg one very large, low pressure positive spring that would top out as the negative chamber is no longer there. This doesn't explain the faster rebound you are reporting though.
  • concorde
    concorde Posts: 1,008
    Will find out soon enough from Mojo. No rebound damping at all, even when I then turned dial to all the way on, like a pogo stick. Will update
  • concorde
    concorde Posts: 1,008
    Well it was a smalley retaining ring and that's it. Caused fork to hyperextend he said which was the lack of rebound I guess?!
  • The Rookie
    The Rookie Posts: 27,812
    Sounds like circlip holding the air shaft in place popped out.
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • concorde
    concorde Posts: 1,008
    Yes think he mentioned something like that. Pain in the arse