Flapping chain, sho...
 

[Closed] Flapping chain, shorten it or is the derailleur spring shot?

Posts: 15554
Full Member
Topic starter
 

As per title, my chain is very flappy, it's pretty much new, as is the cassette, I lengthened it according to the popular 'put it on big /big rings with a two link overlap, with the chain not on the rear derailleur ' method.

But here's the complication.. It's a cheap sram x4 rear mech, and given that I've worn out other bits of the drive chain I'm thinking it might be shot, so the question is, do I pull a couple more links out of the chain or just buy a new rear derailleur? I was thinking maybe a sram x7.

Thanks


 
Posted : 04/08/2015 2:59 pm
Posts: 0
Free Member
 

I'd be looking at a "clutch" mech of one sort or another.


 
Posted : 04/08/2015 3:03 pm
Posts: 7612
Full Member
 

I'd be looking at a "clutch" mech of one sort or another.

If you are 10 speed then clutch mech would be the way to go.

If you are 9 speed then a new mech might do the trick. Sram mechs are quite bad for developing play in the pivots, this can make them feel a bit "baggy" it might also be the spring


 
Posted : 04/08/2015 3:11 pm
Posts: 3642
Free Member
 

Have you checked that the new chain has the same number of links as the old one?

I would take another link out and see how you get on before changing the mech.


 
Posted : 04/08/2015 3:17 pm
Posts: 15554
Full Member
Topic starter
 

It's an 8 speed cassette, triple front if that makes any difference, I'd expect it to be fairly tight as less travel? I think the cassette is 11/34

Thanks


 
Posted : 04/08/2015 3:23 pm
Posts: 17431
Full Member
 

Have you checked that the new chain has the same number of links as the old one?
+1

If it's the same length then could be the mech, if longer then try shortening it to same as old one.


 
Posted : 04/08/2015 3:30 pm
Posts: 15554
Full Member
Topic starter
 

I didn't check the old chain I just binned it :s


 
Posted : 04/08/2015 5:11 pm
Posts: 7612
Full Member
 

Hardtail?

Change into Big - Big

The arm of the rear mech should be pretty tight hanging at about 4 o'clock.

If its not the chain is too long

If you have a full sus then you need to account for chain growth, so in Big-Big a bit closer to the vertical to give you more room


 
Posted : 04/08/2015 5:18 pm
Posts: 0
Free Member
 

Sounds like you have the correct chain length. What's happening when you shift to little/little? Is the mech moving to pull in as much chain as possible or hanging down somewhere in the middle?

If there is still slack in little/little, and the rear mech is moving as it should, you might need a rear mech with a longer cage. If not the mech may be shot and you will need a new one.

Don't shorten the chain beyond big big plus 2 links (in whatever position the chain is tightest if it's full sus) or you could get the chain stuck round the big ring/big sprocket (or rip things to bits going over a bump on full sus). You shouldn't be using this gear anyway, but it is a lot less annoying to have the chain slap about a bit in small/small (which you also shouldn't be using anyway).


 
Posted : 04/08/2015 5:45 pm