rear derailleur

[Chappy]

rear derailleur help

Evening all

I have an old bike that i have refurbished and I got it looking and riding good apart from the rear derailleur.

When the bike is in a stand in the garage I can set it up so it shifts really well and smooth. As soon as I take it out on the road all hell goes on and it jumps all over the place and wont shift properly at all !

Has this happened to anyone else

The derailleur, chain and shifter are all set up for 7 speed so i cant understand it

Any advice would be really helpfull

 

[spandex]

Are all the bolts and QR's tight?

 

[spandex]

And have a look at the chain stays (the bottom tubes that run to the back wheel) are they ok?

 

[Chappy]

Yeah they are all tight and the chain stays look ok

I just cant figure it out

 

[Mr Pig]

If it's all lined up ok it could be a sticking cable or the dérailleur itself that's sticky. Checking the chain is clean, well lubricated and flexible is worth doing too.

 

[Chappy]

I will chek it but the dérailleur is new i will check the cable outer and inners

 

[Mr Pig]

It is more likely to be the cable. New stuff can go wonky though. The front dérailleur on my bike was sticky when the bike was new. Nothing a drop of oil and a wiggle couldn't fix but still caught me out a couple of times.

Did you fit a new chain? If so is it the correct length?

 

[Chappy]

I will measure the chain as well for wear and length

Thanks