TallRider

I've got some Campy Record chainrings, 53/42/30, that I'm using on a Mirage Crankset. The rings were designed for a crank with a "rotated spider" 5-bolt spider where one bolt of the spider is hidden behind the crankarm. Here's the "rotated spider" design, for which the chainrings were made:


And here's the typical design, which is the design of the Mirage crank:


Two considerations here, with using these "rotated-spider" chainrings on a typical-spider crank:[*]The little aluminum piece that sticks out of the large chainring, designed to keep the chain from getting stuck between crankarm and chainrings if the chain falls off, doesn't line up with the crankarm anymore, but is rotated 36 degrees to one side or the other of the crankarm.[*]The pins in the chainrings, designed to help with front derailler shifting, aren't in the optimal part of the pedal stroke anymore.

My question is: should I mount the chainrings rotated 36 degrees clockwise or counterclockwise from their intended position on the crank? Stated differently, should the aluminum pin designed to line up with the Record crankarm be on the clockwise or counterclockwise side of the crankarm? It strikes me that the front shifting may be slightly better one way than the other, but it may not matter at all, alternately.

HillRider

Wow, what an interesting problem. Is there a chain retainer pin on the inner face of the Mirage crank arm or do they all rely on the pin on the chainrings? If the only pin is only the chainring, be real careful how you set the outer limit screw.

As to whether the shaped teeth should lead or follow the crank arm, I guess you can argue the logic either way. About all you can do is pick one way arbitrarily and see if it works out. If shifting is terrible, try the other orientation. Not much help is that?

CBolt

try to think about your personal shifting habits. i think i would like it before the crankarm. but you might wanna try it both ways anyway. i guess i'm not much help either.