SRAM XO cage question
I got a used SRAM XO rear derailleur (I think it was a 2002 model based on the numbers on the cage plate). Anyway I need a long cage for my 3x9 setup for my Lucky Strike. Is it possible to use the newer replacement cage (long ones) for XO (around 2006 or 2007 version)? Do i need to get a complete assembly or the 2 cage plates will be enough. I saw some for 75 USD for the complete assembly. If you have one and not being used let me know. Thanks for the help.
why not just use the cage you have? i have a 3x9 setup and a short-cage xo...you just have to size the chain a little small and make sure you never shift into the large / large or small / small combos (which you shouldn't be in anyway).
to answer your question though, i think they would work but call sram just to make sure. i don't think the desing has fundamentally changed so much as to be incompatible with older parts.
will I have to do the regular chain sizing of big chainring+big sprocket + 2 chain links? Or is there another rule for chain length that I need to consider? Will I just be loosing the ability to use the combinations biggest+biggest and smallest+smallest (i.e. chainring + sprocket)?
Here's info on how to calculate the gear capacity of a derailleur
For rear dérailleurs, the capacity relates to the amount of chain slack the dérailleurs can take up, and is equal to the front range (22 in the example above) plus the rear range. Thus, if you have a 44/32/22 crank set, and a 12-28 (16 tooth difference) cluster, the total capacity required would theoretically be 38 teeth (22 front difference + 16 rear difference).
Manufacturers specify this fairly conservatively. They must do so, because they have to assume that some of their dérailleurs will be sold to incompetent cyclists, who will abuse their drive trains by using the smallest chainwheel with the smaller rear sprockets.
Competent riders can considerably exceed the official rated capacity, since they will not misuse the granny ring by running it with the smaller rear sprockets, so it doesn't matter if the chain hangs slack in those gears.
SRAM has short, medium and long cage X-0's. A medium cage usually has a 33T capacity and the long cage has a 45T capacity. Not sure about the short cage, maybe 28T.