Chain and pin length

[Cal44]

On my bike I had a KMC Z7 chain, I know this from the Spec of the bike online etc, However my bike has an 8 speed at the back so I am a bit confused by this.

Anyway my question is simply that on using my chain checker it would seem the chain is worn and stretched so I purchased a KMZ Z8 the other day due to having 8 speed cassette. The only difference I can see with the chains is the Z8 has a 7.1mm pin length and the Z7 has a 7.3mm pin length. Is the extra 0.2 of a millimetre going to make a big difference?

Also I triple checked and the current chain on the bike has 114 links, the one I ordered has 116. Again will this make a difference or should I just remove a couple of links before fitting?

Cheers!

 

[Yellow Saddle]

The difference in width won't matter. It has to do with the type of rivets on the chain. Chains are never fitted in the length supplied unless by a complete co-incidence your bike requires 116 links. The chain should be shortened to fit the gear set-up on your particular bike. This is usually a few links less than 116.

 

[Cal44]

Thanks Yellow Saddle! I shall simply remove a couple of links then when it arrives. Appreciate your help!

 

[Racing roadkill]

There is an 'envelope' of overlap in pin length / rivet width ( which as pointed out above is the critical thing ) between sprocket spacing. Hence why you see some chains specced for a range of 'speeds' / cassettes. The tolerances get less, when you get to 10 / 11 speeds / sprockets, but there is still some overlap. In short, and to answer your question, no, the 0.2 mm difference won't make a ha pence of difference to your application. As for number of links, I'd be wary of shortening the chain / removing links, on one of my road bikes, simply due to the fact that I have a range of largest sprockets available, and I know through experience that removing more than a couple of links ( from about 116 to 114 ) can cause issues with the biggest sprockets, and the existing rear mech cage. Again going from 116-114 links on a standard type of 8 speed set up won't matter. The 116 chain may not need shortening, you'll have to decide that. You may get a bit of slipping if you put a new chain on an old cassette as well. I tend to use a new cassette with every chain change.

 

[Ajax Bay]

I'd be wary of shortening the chain / removing links, . . . . removing more than a couple of links ( from about 116 to 114 ) can cause issues with the biggest sprockets, and the existing rear mech cage.

Gosh! If a setup needs 112 links, what issues do you think may occur if the chain is reduced from the 116 links that most chains are sold as? Of what should one be wary?

 

[Yellow Saddle]

Gosh! If a setup needs 112 links, what issues do you think may occur if the chain is reduced from the 116 links that most chains are sold as? Of what should one be wary?

Or indeed, why not give some thought to why a new cassette with every new chain?

 

[Cal44]

The chain and cassette have both only done about 1700 miles. So in this instance I was looking to only change the chain. If slippage occurs then cassette is next step. On visual inspection the cassette looks in good nick and I've tried to keep it clean as I can, so I'll be interested to see what happens when the chain is replaced. This is the first time I've gone through this as previous bikes have been so cheap I wasn't bothered. Different story now though!