[kingpin]

The two largest chain rings are worn on my triple bike, and I'm wondering if I can replace them with any rings as long as their the same BD?

 

[Kerry Irons]

Compatibility

The two largest chain rings are worn on my triple bike, and I'm wondering if I can replace them with any rings as long as their the same BD?

The chain rings have shifting pins and special tooth profiles designed to enhance shifting. They are made to work together and with a specific set of derailleurs. Whether another brand of rings will work OK is largely a process of trial and error. Some people report no problems, while others are dissatisfied with the results. Your best bet is to replace like for like, but YMMV.

 

[ericm979]

A "double" inner ring can be used as a triple's middle, but it won't have the pins and ramps that a triple middle ring has got. So shifting from the granny (inner) ring up to the middle ring may not work as well.

 

[Al1943]

Are you sure they ar actually worn? Some of the teeth on the middle and large chainrings are shaped with ramps and bevels to assist in shifting. Have you compared your chainrings with those on a new bike?
If you are sure they need replacing TA Specialties and FSA in addition to Shimano and Campagnolo have chainrings for triples.

Al

 

[kingpin]

well worn

They are well worn. The teeth of the 52 are noticeably hooked, and the middle is not quite as bad. I have an Ultegra and would replace them with any rings with the same BD and number of teeth if I thought they would fit. I noticed the letters A & B in front of double and triple Ultegra chainrings and wondered if they are compatable.