Rattly front changer

[wheeliebin]

The front changer on my venerable MTB has started to rattle quite loudly when I go over a bump. It's a shimano something or other, not an expensive one. I can't see anything broken, and there is nothing to tighten. It is just loose around the pivots, which can't be dismantled as far as I can tell. It still works OK, just annoying.

Time for a new changer? Is it likely to fall apart soon?

 

[fossyant]

They don't rattle. Sure it's not your chain rubbing the mech plates. If it was loose, you'd feel it when you tug on the mech plates !

I'd suggest checking which gear you are in when it does it, if it's one of the end sprockets (at the back) then you may need to adjust the limit screws. Front mechs also have a little 'trim' available to move in or out depending upon where you are. They do rub a little with the chain if you haven't got either the trim right or the limit screws set properly.

 

[wheeliebin]

They don't rattle. Sure it's not your chain rubbing the mech plates. If it was loose, you'd feel it when you tug on the mech plates !

I'd suggest checking which gear you are in when it does it, if it's one of the end sprockets (at the back) then you may need to adjust the limit screws. Front mechs also have a little 'trim' available to move in or out depending upon where you are. They do rub a little with the chain if you haven't got either the trim right or the limit screws set properly.

The part of the mech which moves to change gear is loose when I tug on the mech plates (seems very loose to me). There doesn't seem to be anything I can tighten though, it's all held together with rivet type things. I'm sure it's not the chain rubbing as such, although the fact that the cage is loose might mean it is more likely to cosh the chain as it rattles around.

By comparison the front changer on my newish road bike is tight as a tight thing, it doesn't have any play in it at all.

 

[fossyant]

If the plates/cage bit is loose - i.e. the bit that moves in and out, then it's knackered. New one I am afraid. You just need to get double or tripple depending upon how many front chainrings you have.

 

[wheeliebin]

Thanks for your help, looks as though some more stealth shopping for cycle parts is in order.
As if I'm not in enough trouble already....

 

[lpretro1]

The definitely do rattle when they are knackered! - we see them in our workshop regularly - the pivots wear and the cage becomes loose. Time for a new one!