Chain replacement - advice please

You must consider your chain to be a consumable, like brake blocks.
I'm a bigger rider and I prefer the KMC chains for my riding. The pin strength is much higher than other chains I have used.
I have also found that the KMC chains have plenty of life (certainly more than the lighter Campy and Shimano chains I have also used).
BUT you need to follow these tips:-
1) Use a Chain Checker (even a simply steel one will do).
Replace the chain on 75% worn (0.75) to preserve the teeth on your sprockets and chainrings.
2) Clean the chain every week by wiping it down with a rag and using a brush to remove all the grit from it.
3) Likewise clean the cassette and chainrings.
3) Lubricate that clean chain! My preference is the Eco Range Pure Dry Lube from Halfords which leaves a greasy coating on the chain. Remember to wipe excess oil off the outside sideplates.

KMC chains are good value and well finished but I'd spend a bit more than a tenner and get one that is nickel plated like the X-9 or X-10 silver.

Other than that I prefer SRAM over shimano, mainly for the quick link connection but would avoid the lightened (drilled out) link versions, its the only chain I've had snap on me and it wasn't pleasant.

If you're running a close ratio 10 or 9 speed block then you could try the mavic chains that crc sell for £10 but they have a less reliable shift on a wider ratio block, just seem to be slightly wider than a shimano / sram 10 speed but they will run ok on a 9 speed block.

stuke wrote:

As long as your gears are set up right with decent cables there is very little difference.

I'd agree with you there.

I have been time trialling on Tiagra cassette and SRAM PC951 and I never felt the components slowed me down. Ease pedal pressure slightly as you shift, it enables the chain to move across more easily (I'm not saying you don't do that, stuke).

SRAM's PC971 and PC991 have nickel coating so are slightly more rust resistant than standard PC951 if you neglect it but are not any more durable.

For 8 speed chains I'd avoid SRAM PC830, it doesn't last long. PC850 and PC870 are much better (seen this said lots and my experience is the same).

Hollowpin chains seem to be more prone to failure. Overall, a more expensive chain does not necessarily last any longer.

Buy a chain checker like Park CC-3. Replace the chain at 0.75 and your cassette should last 2 or maybe even 3 chains.

When I was time trialling I'd always use the most expensive cassette and chain I could as they change gear better under load and are lighter, this is more to do with the profile of the teeth on the cassette than the chain though.
For general training or club run style rides the cheaper end of the range are plenty good enough. I change my cassette and chain every 1500-2000 miles and use the cheapest I can get away with. As long as your gears are set up right with decent cables there is very little difference.
For yourself I'd say the KMC ten quid ones will be fine, maybe go up a touch in price for your son's, sprinting out of corners and for the finish line in crits places a lot of stress on the chain.

A cheaper chain from a good manufacturer (SRAM, KMC) will last as long as an expensive one from the same. It'll just be heavier, and may not be 'quite' as smooth.

If you're replacing the chain also have a look at your cassette and chainrings, they could also be worn.

The biggest difference I've noticed between different chains is the weight and 'quality' of the finish on the side plates of the chain. Cheaper chains might be heavier, might not claim 'superior gear changes' and might not be as shiny, potentially they may not have quite the same service life, so far I've not had any experience that confirms this.

The best thing you can do is engage in more frequent maintenance that includes checking the chain for wear and tear using a tool designed for this.