Chain replacement - help!

Maidhci

I need to order a replacement chain for my Giant hybrid bike - I am confused by chain length and I would appreciate some help please.

The original chain was a KMC Z51 - 116 links. A new chain KMC X8 99 - 8 speed - 116 links was fitted two years ago. It appears that the KMC X8 99 is no longer available and has a successor KMC X8 - 7/8 speed - 114 links.

Given that this chain is two links shorter than the previous model, I presume that it is a shorter chain and wondering if it could be the correct size for my bike.

Any help greatly appreciated.

magicbastarder

did you replace the chain yourself last time?
usually a chain is sold longer than required and shortened to the correct length when fitted (which varies based on your particular gearing)

Maidhci

magicbastarder wrote: »

did you replace the chain yourself last time?
usually a chain is sold longer than required and shortened to the correct length when fitted (which varies based on your particular gearing)

No, I didn't - it was fitted by a bike mechanic, supplied by me, but he confirmed that it was the correct replacement type. Given that the original and the replacement were 116 links, my confusion arises given that the successor chain, as outlined is shorter.

magicbastarder

he almost certainly shortened it before fitting it. you could count the links on the chain as is to clarify for yourself.

Maidhci

magicbastarder wrote: »

he almost certainly shortened it before fitting it. you could count the links on the chain as is to clarify for yourself.

I think I checked with him at the time and he stated that it was the same length. The original chain fitted to the bike was a 116 link KMC Z51.

smacl

Maidhci wrote: »

I think I checked with him at the time and he stated that it was the same length. The original chain fitted to the bike was a 116 link KMC Z51.

As magicbastarder has indicated, you normally get a chain with more links than you need and shorten it, this is still the right chain. You need to count the links on your current chain. There's most likely a slightly different looking link, a quick link used to join two ends, so count from there and do not include that link. If you're fitting yourself, you'll most likely need a chain breaker to shorten the new chain and I'd recommend also getting a new 8 speed quick-link. Handy enough to do, but if you don't fancy it get your local bike shop to do it. See below;

https://www.youtube.com/watch?v=VdUQKVMPF5I

lissard

Any 8 speed chain will do fine - the chain is always shortened during fitting. Just lay the chains side by side and trim as appropriate.

Seth Brundle

lissard wrote: »

Any 8 speed chain will do fine - the chain is always shortened during fitting. Just lay the chains side by side and trim as appropriate.

...but bear in mind that the old chain may have stretched.

triggermortis

lissard wrote: »

Any 8 speed chain will do fine - the chain is always shortened during fitting. Just lay the chains side by side and trim as appropriate.

It’s better to count the links as the old chain will stretch

Maidhci

smacl wrote: »

As magicbastarder has indicated, you normally get a chain with more links than you need and shorten it, this is still the right chain. You need to count the links on your current chain. There's most likely a slightly different looking link, a quick link used to join two ends, so count from there and do not include that link. If you're fitting yourself, you'll most likely need a chain breaker to shorten the new chain and I'd recommend also getting a new 8 speed quick-link. Handy enough to do, but if you don't fancy it get your local bike shop to do it. See below;

Thanks for this info and link. I haven't yet ordered the chain, just wanted to make sure I was ordering the correct one, to avoid having to return and as I intend having it fitted in a workshop, it probably would not be accepted as a return etc. I have counted the links on the current chain, it has 116 links, including the masterlink. Therefore 57 outer links, 58 inner links plus the masterlink - I hope this makes sense. Therein lies my concern - it would not be a problem shortening a chain by one or two links, but the opposite appears to be the case here.

With this info, do you still consider that the KMC X8 - 7/8 speed would be suitable? Many thanks for your help.

Maidhci

lissard wrote: »

Any 8 speed chain will do fine - the chain is always shortened during fitting. Just lay the chains side by side and trim as appropriate.

I haven't yet ordered the chain, it would not be a problem shortening the chain but the current chain is slightly longer than the one outline in my question.

cletus

If you're getting your LBS to fit the chain, maybe just ask them to order it too

magicbastarder

it's possible your chain should have been shortened, but hasn't; if you drop to the smallest ring up front, and smallest at the back, does the lower run of chain still run clear of the upper jockey wheel?

smacl

Maidhci wrote: »

Thanks for this info and link. I haven't yet ordered the chain, just wanted to make sure I was ordering the correct one, to avoid having to return and as I intend having it fitted in a workshop, it probably would not be accepted as a return etc. I have counted the links on the current chain, it has 116 links, including the masterlink. Therefore 57 outer links, 58 inner links plus the masterlink - I hope this makes sense. Therein lies my concern - it would not be a problem shortening a chain by one or two links, but the opposite appears to be the case here.

With this info, do you still consider that the KMC X8 - 7/8 speed would be suitable? Many thanks for your help.

If you're counting 116 links in total on your current setup and shifting works well, I'd go for a 116 link chain, e.g. this one https://www.wiggle.co.uk/shimano-hg40-6-78-speed-chain or if you prefer KMC this one; https://www.wiggle.co.uk/kmc-z8rb-anti-rust-8-speed-chain You'd more than likely get away with the 114 links but certain gear combinations such as biggest ring up front and biggest cog at the back (which you shouldn't really use anyway) might cause problems.

Maidhci

magicbastarder wrote: »

it's possible your chain should have been shortened, but hasn't; if you drop to the smallest ring up front, and smallest at the back, does the lower run of chain still run clear of the upper jockey wheel?

Thanks for this, magicbastarder - Yes, it is well clear of the upper jockey wheel. I had already carried out a check outlined in a Park Tools tutorial - in the largest front and rear sprockets, there is a slight bend at each pulley and chain shifts easily to largest sprocket; in the smallest sprockets, there is very little slack in the chain and the derailleur does not go back to such an extent that the chain makes contact.

CramCycle

The 114 will be grand