New chain help ?

[BADGER.BRAD]

Hello all,

Over the weekend I fitted a new KMC chain to My 8 speed revolution courier the chain said for 6/7/8 speed or 18./21/24 as I went to work this morning I realized that in top gear the chain kept jumping so just rode to work avoiding gear 8. When I got home I could see nothing wrong the Jockey wheels are well clear of the cassette , as I rotate the chain with out pressure there is no problem yet on the road even with the slightest load the chain jumps ( difficult to view whilst riding !) I then decided to go through the bin and find the old chain, I did a comparison and found no difference cleaned up the old chain and found that its even the same make and marked as narrow. Yet with the old chain there is no jumping. The original chain has done about 1000 miles through horrible winter conditions with just an occasional oil so hasn't done too bad as specially as most for the time it's running in top gear at quite an angle ( single chain ring to highest gear)

Any ideas anyone ?

Thanks all

Brad

 

[bauldbairn]

Maybe your sprockets are worn and the old chain just fitted into them perfectly.

I've also got an 8 speed Revolution Courier(2009) - I've done more than 2500 on the original chain and sprockets with no signs of wear. I cleaned and oiled the chain every week though.
I now use it only to cycle the 2/3 miles to work when I'm mid-shift and it's still ok - although the bottom bracket has got a bit crunchy(lack of use since buying a new bike).

 

[Cheule]

Is the quick release pin sticking at any point?

 

[BADGER.BRAD]

Is the quick release pin sticking at any point?

Not as far as I know but I will give it a try, the only thing with this is wouldn't that affect both chains ?