Join Date: Jul 2000
Bikes: 1959 Capo; 1980 Peugeot PKN-10; 1981 Bianchi; 1988 Schwinn KOM-10;
Mentioned: 8 Post(s)
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There are at least three ways to assemble a triple:
1) (most common): the two outer rings bolt to the spider and the inner bolts to a smaller BCD set of holes on the inside of the spider. This is the system for which your new chainrings are designed.
2) (triplizer; your old setup): the two outer rings bolt to the spider and the inner bolts to a second row of holes in the middle ring. If you want to retain this system, you will need a new middle ring which has the second set of holes, as your old one did. Harris Cyclery or LooseScrews may have what you need.
3) (least common, smallest range): all three rings bolt onto a single set of holes in the spider, using long stack bolts and spacers.
If you want to go with the first option, you will need a new right crank. The second option will require you to exchange that new middle ring for a triplizer ring. The third option will require you to accept a larger grannie and buy a set of long stack bolts, assuming you can find them. They are pretty rare.
"Early to bed, early to rise. Work like hell, and advertise." -- George Stahlman
Capo [dschaw'-poe]: 1959 Modell Campagnolo, S/N 40324; 1960 Sieger, S/N 42624
Peugeot: 1970 UO-8, S/N 0010468
Bianchi: 1981 Campione d'Italia, S/N 1.M9914
Schwinn: 1988 Project KOM-10, S/N F804069