[mobius]

Is their a diff or downside to shorter derailler cages or are only changes weight savings and not as long to break? Their has to be reason why they make long and medium cage ones.

 

[srf]

Short cages are supposed to shift better, but unless you're running a double crankset it won't be able to hold enough chain. Shift into large rings front & rear and you'll have a derailluer to replace...

 

[SwisSlesS]

Originally posted by srf
Shift into large rings front & rear and you'll have a derailluer to replace...

However if you're an experienced biker, you would know that you're not supposed to shift into that gear, so you might not have to worry about it so much.

 

[Mecannoman]

Cage length has to do with the size of the largest rear cog. The larger the cog, the longer the cage. A longer cage allows you to run more chain for triple chainring sets (without having the chain run on itself in smaller cogs). That's why you don't see long cage ders on road bikes with two chainrings. As swiss_less says, if you shift properly, you should be able to get away with a shorter cage!