New chain

[revvers]

As I understand it, to fit a new chain I should count the number of links on the old chain and use this as a guide on my new one (?) If you are replacing the cassette with one of a bigger size, should you therefore make the chain bigger, and if so , by how much?

 

[revvers]

I thought you had to count the links in case the chain has stretched? By how much should you make the chain longer in relation to cogs? i.e one link per extra cog?

 

[PatrickPending]

I thought you had to count the links in case the chain has stretched? By how much should you make the chain longer in relation to cogs? i.e one link per extra cog?

it shouldn't have stretched that much - the park tool chain checker recommends replacing at a 1% stretch, tho if you go beyond this (by a long way) you'll eventually reach a point where the chain starts to fall to bits before any great stretch.

As above increase links by the number of extra teeth on large ring of the new casette

 

[Joe24]

I never did that, used to put the new chain on the big chainring, then on the biggest sprocket, and add 2 links onto that(or about 2 links)
Never did any counting or putting chains up against each other.

 

[Seamab]

Don't bother counting the links, just put the new chain next to the old

This only applies if the old chain is the correct length!

I had my bike in at the LBS recently and was told i had too many links in the chain. The original chain length being set when i purchased the bike. Never thought to check it wouldn't be setup correctly.

 

[Saddle bum]

Put the new chain on the smallest ring and smallest sprocket. Adjust length so it just takes up the tension on the rear derailleur. Allow for a little stretch over time. You can then change wheels and cassettes and not worry abount the big sprocket size. Changing chains before they overstretch means not having to swap out sprockets and chainrings - an expensive business.

Campag 10-speed, 2000 miles max.
Shimano 10-speed, less than 2000 miles
KMC, dunno, just started using them. Anticiapte 2k miles.

 

[zacklaws]

I've just replaced my chain on my bike, and I found that laying the old next to the new, did not match up as my old one had worn so much that if I had not counted the links, I would have been a complete link too many if I had gone to the nearest of the old chain. Probably would not have made much difference though.

The unfortunate thing was, the chain was well worn, too many hills and too much standing to pedal I think plus 3000 miles on it, that I also had to replace the cassette and my chain rings. In future I will keep a better eye on the chain and replace after about 1500 to 2000 miles to prevent wear to the other components.

 

[Jonathan M]

Put the new chain on the smallest ring and smallest sprocket. Adjust length so it just takes up the tension on the rear derailleur. Allow for a little stretch over time. You can then change wheels and cassettes and not worry abount the big sprocket size. Changing chains before they overstretch means not having to swap out sprockets and chainrings - an expensive business.

Campag 10-speed, 2000 miles max.
Shimano 10-speed, less than 2000 miles
KMC, dunno, just started using them. Anticiapte 2k miles.

Isn't it safer to put a new chain on big:big, then add one link, as per (I think) Shimano instructions? This allows for the worst case scenario of using big:big whe riding, and should mean the drivetrain won't jam, or the rear mech break.
Surely using small:small & taking slack up on the rear mech would result in a very short chain, possibly really slick changing but also a drivetrain that wouldn't tolerate under any circumstances going into big:big?

 

[Saddle bum]

Isn't it safer to put a new chain on big:big, then add one link, as per (I think) Shimano instructions? This allows for the worst case scenario of using big:big whe riding, and should mean the drivetrain won't jam, or the rear mech break.
Surely using small:small & taking slack up on the rear mech would result in a very short chain, possibly really slick changing but also a drivetrain that wouldn't tolerate under any circumstances going into big:big?

I think you misunderstand me.

"Put the new chain on the smallest ring and smallest sprocket. Adjust length so it just takes up the tension on the rear derailleur."

"Just takes up the tension" means just that, with a slack cage, adjust chain until it just puts a little tension into the spring. Assuming you never put a smaller sprocket or chainring on, you can do what you like at the other end.

I have a 14t top sprocket on my sportive bike, but change the cassette to a moutain goat type when going on hols or "up country". It does not have any consequences so long as the total set up is within the capabilities of the derailleur.

My Audax bike has the same arrangement, a 13t top - 30/40/50 rings, I can change to a more relaxed cassette on different wheels whenever I choose - no worries.

 

[Jonathan M]

OK, not seen that method before, I've always gone for the big:big and add a link. So in practice would there be any significant benefits using the method you describe over the method I've been using?

BTW on my MTB it already has a 32 on the rear, so no plans to change that, on my winter bike I've swapped between a 28, a 25 and a 23 without any problems chain length wise.

 

[Saddle bum]

It's as much as makes no difference really. So long as the overall big:big and small:small is within the capacity of the derailleur, allowing for swapping around of cassettes and rings.

However as an engineer, I believe that running the transmission so that the derailleur spring tension is not running at its limit, improves the life of the chain and toothed parts as well as the chain.

However it is not beyond reason to run more than one chain depending on the requirements of your gearing throughout the year. The KMC split-links make this an easy prospect. It is also possible to run two chains at the same time, one cleaned ready for use whilst using the other, just swap them around when it comes to cleaning time. This has the benefit of keeping the wear on teeth to a minimum. My present transmission, Campag 10-speed, is five years old and shows no sign of excessive wear, I just keep on replacing chains.