Cranks turn but wheel doesn't

jefflad
jefflad Posts: 315
edited February 2013 in MTB workshop & tech
Hi, My mate's brought his bike round as having trouble pedalling. It's a old-ish bike but with the bike stationary and with the brakes on, you apply pressure on either pedal the cranks turn but the bike gives off a sound of a machine gun and obviously the bike isn't moving...

It's quite hard to see in the light if the teeth on the front cogs are just too worn but it happens on all 3 rings or is it something else, like the freewheel?

I guess it's one of these... has anyone a better idea or some pointers before we take it apart at the weekend?

Comments

  • nicklouse
    nicklouse Posts: 50,675
    buy a torch.

    could be any and all of the above.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • The Rookie
    The Rookie Posts: 27,812
    Can you see what's happening....is the chain moving, the rear sprockets?
    Logically it's chain not being pulled round by the chainwheels, or the chain riding over the sprockets or a failure of the rear freewheel so the sprockets are spinning not the wheel, shouldn't be hard to figure which!
    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.
  • jefflad
    jefflad Posts: 315
    Yeah, it looks to be the freewheel, we'll take it apart at the weekend and have a proper look.
  • njee20
    njee20 Posts: 9,613
    I've never seen a chainset so worn that the pedals turn and the wheel doesn't, that would be impressive indeed!

    Freehub/freewheel depending on how expensive the bike is.
  • jefflad
    jefflad Posts: 315
    njee20 wrote:
    I've never seen a chainset so worn that the pedals turn and the wheel doesn't, that would be impressive indeed!

    Freehub/freewheel depending on how expensive the bike is.

    LOL... I know, in the cold light of day when we were having a beer watching the end of the England game we did agree it can only be the freewheel at the back :)
  • jefflad
    jefflad Posts: 315
    All sorted now... it was the freewheel... it's amazing what parts you can 'borrow' of the wife's bike :roll:

Categories