Rear Der, long cage or medium cage?

[JOx2]

what is more suitable for an EMD 9 medium frame, RD long cage or medium cage?

[Uncle Rico]

If your running it 9 speed, I would go with the short cage. If your running 27 speed, I would use a medium cage.

[JOx2]

i dont know the mechanics behind it, but care to explain why short cage on a 9 speed?

[Pato]

3x9 - long cage
2x9 - medium cage

[jbiron]

It has to do with the difference between the amount of chain that wraps around largest chainring/largest cog combo and the smallest chainring/smallest cog combo of the possible gears you could choose and the ability of the derailer to take up the slack. A longer cage can take up more slack.

Most bikes have a largest possible 42/34 combo. In this gear the derailer cage is amost straight in line with the chain. The smallest possible for most bikes is a 22/11. In this gear the cage is tucked back rearward to take up the chain slack.

[BrewMaster]

It depends on the gearing you are running.

This is the best explanation I have ever seen.

[roadkillross]

sorry to derail but what about a 1x9

[skate]

Originally Posted by roadkillross

sorry to derail but what about a 1x9

short, but you should know that. didn't or don't you ride DH

[TBlazen]

It's all about chain tension in the end....more is good and 1x9's dont need to strech as far...So go with the short cage....