Bicycle Mechanics - DA 7700 RD and the "Century Special" Cassette

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tlarwa
08-06-08, 09:33 AM
I've read the few posts here regarding the Century Special 13-30 cassette from Harris Cyclery, but am still not sure what will work. I am currently running full DA 7700 9-speed, and the RD is the standard short cage. Although the Harris website claims that a standard RD ought to handle the 13-30 combination, some of the posts I've read seem to dispute this. My question is whether the DA 7700 (or 7800) GS version (long cage and bigger pulleys) will better accomodate the 13-30 cassette. Help?

Gonzo Bob
08-06-08, 11:17 AM
The spec for both 7700 and 7800 and both short and long cage is max cog of 27T. However, in many cases they will run fine on a 30T cog. It really depends on the frame, i.e. length and thickness of derailer hanger. I got my Dura-Ace to run on a 13-30 with no problems. You may have to fiddle with chain length and/or the b-screw adjustment.
tlarwa
08-06-08, 11:55 AM
The spec for both 7700 and 7800 and both short and long cage is max cog of 27T. However, in many cases they will run fine on a 30T cog. It really depends on the frame, i.e. length and thickness of derailer hanger. I got my Dura-Ace to run on a 13-30 with no problems. You may have to fiddle with chain length and/or the b-screw adjustment.

Thanks. I guess I'll just give it a try and go from there. Worst case I end up throwing on an XT/XTR rear derailleur and calling it a day.