Mountain Biking - medium & long cage derailleurs... tooth capasity question
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At SRAM web site, it says medium cage derailleurs have 37, and long cages have 45 total tooth capacity. (http://www.sram.com/_media/pdf/sram/dealers/TM_MTB_MY05_E.pdf)
The total tooth of my drivetrain is 37 (22/32/44 12-27), so medium cage will be a perfect fit.
But in the future if I want to change my cassette for some reason, say to an 11-32, it will exceed the capacity by 6.
My question is, will the medium cage handle the wider range gears with a longer chain, and will I be able to use all of the gears?
05-04-05, 07:27 PM
Probably not, so go with the long cage.
05-04-05, 09:05 PM
It'll handle all the **useable** gears, plus you want it to handle accidental cross-chaining to the big-big combo. But you can't expect it to handle shifts into the small-small cross-chain combo -- if you do go there, the cage will double up on itself, lose chain tension, and allow the chain to drop.
Medium cage is really the way to go for increased chain tension, decreased chain slap, crisper shifts, quieter running, raised obstruction clearance, and improved spoke clearance.
Don't go there if you want the ability to shift to small-small and remain there.
I always try to avoid using cross gears (like big-big or small-small), and try to use like small chainring-big five, mid chainring-mid five, big chainring-small five. So even if I change the cassette (which I don't think I will anyway), it seems like having a medium cage won't be a big problem. Given the advantages of a medium cage derailleur, I guess it's worth it.
Thanks a lot for the info!
medium should work fine. I have a 11-32 rear cluster and 40t fron chainring on my bike. Mine is a short cage road derailleur and my bike is dually with a bit of chain growth.
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