I have an older (95) Schwinn Paramount with a Shimano 105 group on it. I have been riding this for many, many miles and recently put on a new cassette and new chain and decided it would be a good idea to get new chainrings as well. I purchased a new set off e-bay that seem lighter and look quite a bit different from what came off. They are for a model FC-5502.
They have some weird machining on them that looks like a wear pattern, some small rivet looking things that are placed around the ring. I don't know, I would hope Shimano has a method to it's madness. I put them on today and it shifts OK on the stand but required some adjustment. Does anyone know what the deal is with these rings??
Yeah, yeah..I know I about the "Shiano" in the title..it's happy hour here!
Last edited by bykemike; 12-13-09 at 05:04 PM.
The rivet looking things are pick-up pins and help the chain shift up to a larger chainring, smoother and quicker. You may notice that some of the teeth have special shapes or ramps, also shifting aids.