New Durace cassette and "clicking chain -Help

[earthman309]

I just installed a new 12-25 Durace cassette on my wife's Merlin Ariel Triathlon bike and have found that it has developed a nasty chain click when in the 50/15 combo. The 14/50 and 17/50 are silent but no matter how I alter the derailleur tension the 15/50 has a nagging clickity clack. I even when as far as swithching the 15 tooth cog from the Ultegra cassette that had been on previously. The chain is a low mileage Shram and the cranks are a set of FSA compacts (50/34). My wife has only ridden the combo ~ 20 miles so perhaps things will "wear in" but I've never had this sort of problem in the past.

Any ideas?

Thanks for any informed replies.

Hugh

 

[wilmar13]

I just installed a new 12-25 Durace cassette on my wife's Merlin Ariel Triathlon bike and have found that it has developed a nasty chain click when in the 50/15 combo. The 14/50 and 17/50 are silent but no matter how I alter the derailleur tension the 15/50 has a nagging clickity clack. I even when as far as swithching the 15 tooth cog from the Ultegra cassette that had been on previously. The chain is a low mileage Shram and the cranks are a set of FSA compacts (50/34). My wife has only ridden the combo ~ 20 miles so perhaps things will "wear in" but I've never had this sort of problem in the past.

Any ideas?

Thanks for any informed replies.

Hugh

I'm not really familiar with Shimano, but Campy uses different width spacers between cogs, if you mix them up, the exact same thing happens with Campy. You end up with the spacing slightly too wide on one gear and too narrow on another causing the chain to rub lightly against the adjacent cogs even if derailleur adjustment is perfect.

 

[gclark8]

Its a minor cable adjustment, at the RD, each cassette may be just a little bit different. Try a couple of clicks "out" first.

34/50 and 12-25 seems a little low in gearing for a tri bike? Is the chain a bit long?

 

[earthman309]

Its a minor cable adjustment, at the RD, each cassette may be just a little bit different. Try a couple of clicks "out" first.

34/50 and 12-25 seems a little low in gearing for a tri bike? Is the chain a bit long?

George,

Thanks for the reply. My wife was second in her age group and at IMLP and 8th in Kona so the gearing works pretty well for her. At 54 her enduance trumps her power. Its so nice to spin up the hills of Lake Placid especially on the second loop.

I already shortened the chain what I feel is an appropriate amount as well as gone multiple clicks in, out and every else in between. I'm starting to wonder if the 17 tooth that grouped in the 19 and 21 is a bit tweeked. Its never taken me more than a minute or two to make this type of adjustment before.

Tomorrow the Durace will come off and the Ultegra will go back on to see how it performs.

Hugh

 

[gclark8]

OK, you the get nasty chain click when in the 50/15 combo, what happens when you drop the front to the 34?

Another thought is short chainstay length, should not be a problem with bigger rings, can be with a 30 on a triple.

I am over 55 and prefer light spin loads too, my Felt is 30/42/52 & 13-23 9 speed 700c wheels. My Try bike, 30/42/53 & 12-23 9 speed with 650c wheels.