Changed chain - Now have rear dérailleur issue

CatFromHue

I changed the chain on my bike but now have a rear derailleur problem.

The bike hasn't been used for a good few months now but worked fine last time it was used.

Big cog on front derailleur


Small cog on front derailleur


As you can see when I'm on the big cog on the front derailleur it's ok (ish) but when I changed to the small cog on the front derailleur the rear derailleur falls back in on itself.

I got a 9 speed chain assuming that it fitted a 9 cog cassette.

Any ideas as to what's going wrong?

monkeyslayer

Looks like your chain is too long, measure it against your old one and you'll know for sure

Wishbone Ash

As monkeyslayer said.

Did you measure it against the old one. Have you still got the old one?

If you don't have the old one you'll need to put it on both extremes to check the length - i.e. needs to fit largest rear on large front and smallest rear on small front. If in doubt remove one link at a time (measure twice-cut once).

Wishbone Ash

Just to add that chains are sold to accommodate a large rear sprocket such as a 30 coupled with a 53 at the front. The vast majority of set-ups don't require that length and the chain is shortened to the required size.

CatFromHue

Yup the chain is too long

Cee-Jay-Cee

I'd say you have 4 or 5 links too many on the chain.

CatFromHue

Cee-Jay-Cee wrote: »

I'd say you have 4 or 5 links too many on the chain.

Good guess!