|Dura Ace Chainring Markings???||Lefler|
Dec 3, 2002 8:32 AM
|I recently purchased a set of used of D/A chainrings. Stamped on the big ring is the marking SG B-53. I am curious as my existing Ultegra rings have the same marking stamped on them. What is there to differentiate between the groups? Also the smaller ring doesnt appear to have the indexing triangle stamped on it?? TIA|
|re: Dura Ace Chainring Markings???||mpm32|
Dec 3, 2002 10:49 AM
|someone told me once that they are the same rings.|
|re: Dura Ace Chainring Markings||Chen2|
Dec 3, 2002 11:43 AM
|Can't answer your question but I can tell you that the tooth count stampings go to the left on the inside ring and to the right on the big ring.
|re: Dura Ace Chainring Markings???||the other Tim|
Dec 3, 2002 12:27 PM
|I believe that the 'A' group is for 53/42, the 'B' group is 53/39, and the 'D' group is 53/39/30. I don't know if all of the 5x/4x combinations are 'B'. Shimano says that mixing the groups can result in improper spacing, but I think they're referring to double/triple group mixing, and the A/B designation is about pin/tooth alignment for smooth shifting.
I don't know what to say about the missing index mark, but the text markings are usually opposite (180 deg.) the index.
I'm sure 'SG' means 'Super Good'.