Cassette & chainrings

[fossala]

If you need to borrow any tools or need to be shown how to replace it give me a shout as we seem to live in the same town.

 

[Smurfy]

Measure the chain with a 12 inch steel rule. In a new unworn state the dimension from pin centre to pin centre should be exactly 12 inches.


View: https://www.youtube.com/watch?v=5okJdYrANt8

 

[Newman8]

I've always understood that a chain & cassette should have the same level of wear as one another & be replaced at the same time - so a new chain performs better with a new cassette (& 8-spd Shimano spaced cassettes are dead cheap which is good)...
Two more possible reasons though is that (a) the bottom bracket shell area could actually be flexing when your pedalling hard - e.g. uphill - or 'under load' as you say - which means that your are physically moving the gear cable a little where it runs under the bb shell & carries on to the rear derailleur & that's causing the chain to try & skip to the next gear, or (b) another reason is that the cables themselves are old or rusty preventing the gear indexing from engaging correctly.

 

[jps71]

Thanks for all of the replies

 

[jps71]

If you need to borrow any tools or need to be shown how to replace it give me a shout as we seem to live in the same town.

Thanks Fossala for the offer I think I have the tools just need to get the cassette now.
Then I will see if the old one comes off.
I am in Stenalees.
Cheers Jim

 

[jps71]

I've always understood that a chain & cassette should have the same level of wear as one another & be replaced at the same time - so a new chain performs better with a new cassette (& 8-spd Shimano spaced cassettes are dead cheap which is good)...
Two more possible reasons though is that (a) the bottom bracket shell area could actually be flexing when your pedalling hard - e.g. uphill - or 'under load' as you say - which means that your are physically moving the gear cable a little where it runs under the bb shell & carries on to the rear derailleur & that's causing the chain to try & skip to the next gear, or (b) another reason is that the cables themselves are old or rusty preventing the gear indexing from engaging correctly.

Thanks for the reply.
I will look in to the bottom bracket flexing.
I fitted new gear shifters recently & replaced all of the cables both inner & outer so cant see that being the problem.