Chain jumping under pressure

[Matthew_T]

And keep your old chain mate, you need to cut down the new one to the same size as the old one, otherwise you'll end up with a similar symptom in the shape of a chain that's too long.

Get yourself a decent chain link extractor and it's a 5 minute job.

Already got a chain link tool. And I had to cut down the original chain by 3 links because I was incuring that problem. The chain I have ordered is an 8 speed (not sure if that matters).

 

[subaqua]

Already got a chain link tool. And I had to cut down the original chain by 3 links because I was incuring that problem. The chain I have ordered is an 8 speed (not sure if that matters).

8 speed is marginally fatter than 9 speed which is marginally fatter than a 10 speed. the space to fit the extra sprockets on the casette means the higher the number of speeds the narrower the sprockets are.

ideally a 8 speed cassette needs an 8 speed chain etc etc

 

[e-rider]

I have had the bike for about 4/5 years with the original chain and sprockets on. So I would say about 7,000 miles???????

you need a new chain and a new cassette - simple

if you replace the chain every 1500 miles the cassette will last perhaps 8000 or more miles depending on its quality, however, using an old chain will wear the cassette much faster. In your case both items are ready for the bin! You've done very well to get 7000 before the chain has started to jump.

As for the wear, this is very hard to notice on the cassette just by looking at it. Chain wear can be checked using a tool that costs about £10; Park Tools make a good one.