chain seems to have grown several sizes

[galaxy1]

This morning on my commute my chain came off (my dawes galaxy) and got stuck between the chain and smallest chain ring ,it was pretty firmly stuck!! After much swearing I got the chain free and back onto the chain ring but theres a problem.The chain seems very very slack indeed as if its grown a few sizes.The deraillier is still indexing between gears (front and back) .I don't get it.Does anyone have any ideas as to what could have happened and how to fix it?

 

[HJ]

Time for a new chain.

 

[galaxy1]

The chain is only a month old though....

 

[swee'pea99]

There's no way you could have stretched your chain - chains don't stretch. The only thing I can think of that could explain the symptoms you describe is if the sudden jerk shifted your wheel. Try shifting it back to take out the slack.

 

[swee'pea99]

...or....come to think of it - is your rear mech still keeping the tension? That's one of its jobs. Could be the spring has broken or come adrift somehow? If you physically push the bottom end towards the chainwheel, does it push back against your fingers? If not, it's your mech that's gone.

 

[galaxy1]

I ended up coming in on my other bike so I'll have a look when I get back .I really hope its not the deraillier

 

[Jonathan M]

Lost a jockey wheel from the rear mech maybe? Couldn't see the rear mech indexing if the spring is FUBAR.

 

[andrew_s]

Lost a jockey wheel from the rear mech maybe? Couldn't see the rear mech indexing if the spring is FUBAR.

There are two springs - a visible one across the parallelogram that does the gear changes, and a coil spring in the cage pivot that does the chain tension.

 

[galaxy1]

If it is the spring does that mean a new derailliour or can it be fixed?

 

[Globalti]

I doubt the spring has broken; possibly it has come adrift but it shouldn't. Is the derailleur body still firmly attached to the frame?

 

[galaxy1]

Thanks everyone. I had a look and it seems that all the riving about with the chain shifted the wheel ,I moved it back so thats all super..touch wood

 

[Jonathan M]

Thanks everyone. I had a look and it seems that all the riving about with the chain shifted the wheel ,I moved it back so thats all super..touch wood

Tighten those QR's properly next time