I was riding rather close to cross chaining almost all the time in the big ring, 53T. so with all the success of the compacts i thought I would just buy a 50T 130 bcd ring and slap it on there and adjust the hieght of the derailer. well it shifts great and i really like the 50T on there, i can ride more in the middle of the cogs. as it turns out it was a chainring from a triple, 50T,40T,32T... or something like that and it makes a noise as i ride. it is not the derailer rubing it sounds like dirt in the chain kind of, but only in the 50T not the 39T. it is a 10 speed chain maybe the ring is to wide... i really can not guess on this one. does anyone have any suggestions?

you need a long cage deurailler for a triple crank...

Okay, this is probably a silly question, but, if you were spending most of your time in the lower gears, why didn't you just shift to the 39T ring? Another alternative would have been a 12/27 cassette. Or, if you already have a 12/27, go to a 11/21 and stay in 39T. Try playing with Sheldon Brown's gear calculator.

He's using a chainring from a triple crank on a double, not a triple crank on a double crank setup.


OP: The 50T chainring could be worn, compare the teeth to your old chainring. If they're narrower (more like a shark fin) that's a good sign of wear which would cause the noise your describing.

Hocam, the ring was brand new. thats what i dont understand.

Measure the respective chainring widths...replacement with original but also check to see if there is shift pin misalignment. I had a good discussion with Campag tech a few years ago and was told not to mix rings between triples and doubles for that reason as shift pin location is matched between designated rings.

Weird. It's a new chain too? If you take a ruler to the center of one link, the 12" mark should hit less than 1/8" away from the center of a pin 24 links away. If it's a brand new ring and a slightly stretched chain that might do it too.

I don't think the ring would be too wide, 9 speed era chainrings work fine with 10 speed chains.

You're sure it's not a little bit of FD rub?

the chain is not brand new, but there is little to know strech in it. they are different brand rings, Campag maybe the shift pin location has somthing to do with it. does any company make a 130 bcd in both 39 and 50? I dont want a compact, i dont want to spend the money and two i dont want to go lower then 39.