Bicycle Mechanics - Does KMC chain shift as well as Shimano or Sram?

Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.




diddidit
05-12-10, 05:23 PM
My wife's Cannondale Synapse mixes a KMC chain with 105 3x10 derailleurs and a Sram cluster. She's got ghost shifting issues and general noise from the RD, both of which I can confirm from riding with her. On the stand I can't duplicate the ghost shifting, but the noise I can. I've tweaked and adjusted and even given dirty looks, but I just can't settle the thing down to be as quiet as my 7800-equipped bike.

It looks like the noise comes from the chain juuuust catching on an adjacent tooth of the next-larger sprocket, and then uncatching. It's most prominent in the smallest sprockets, especially when in the middle ring.

On a hunch, I measured the KMC chain, and compared it to new Shimano and Sram chains; the KMC measures ~6.1mm, while the others are 5.95mm (assuming I remember how to read a vernier caliper right). Dunno if that matters, and I think I recall that Shimano's spec is 6.1, but it's interesting nonetheless.

So, ideas? Anyone think a new Sram chain would help?

Thanks -

did


reptilezs
05-12-10, 05:28 PM
too much tension, or something is bent

FBinNY
05-12-10, 05:54 PM
It's a trim issue of some kind. Either the RD is mis-adjusted mis-aligned. Mis-alignment can be the result of a bent hanger, or because of a twist or bend within the RD itself.

The other possibility is that the chain is the wrong type, as in 6s for a 9s system and it's too wide.

Determine which by looking at the chain at the top of the cassette. If it sits nicely on a sprocket and clears the adjacent one, you know the chain is fine, and it's the RD that's feeding it to the cassette improperly.


diddidit
05-12-10, 05:58 PM
OK, tweaked a bit more. Amazing what a difference having some dinner makes! Actually needed more cable tension, then fine adjustments. Hits 'em all quietly now - we'll see how it goes on the road, but it's better on the stand now.

Thanks for the sounding board...

did

mrrabbit
05-12-10, 06:29 PM
Does a Shimano chain made by KMC shift as well as a KMC chain made for Shimano?

:innocent:

ultraman6970
05-12-10, 07:42 PM
Probably KMC chain made by KMC and sold under KMC brand shifts better and last longer than anything in the market right now.

larry_llama
05-12-10, 07:50 PM
I buy, use, sell and recommend only KMC chains. They offer the best value and have the easiest to use master link. Glad to hear the adjustment quieted the beast!