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Long cage vs Medium cage. Difference?

5K views 11 replies 7 participants last post by  mattbikeboy 
#1 ·
I am upgrading my rear derailleur (and probably front and shifters while I am at it) because I am sick of my bike ghost shifting on me. I have done a lot of research on the products out there (probably gonna go w/ SRAM X9 & X7 shifters) but I cannot find anywhere that clearly describes what the performance and shifting difference is between a long cage and medium cage.

I am inclined to go for the medium since it will get banged around on less stuff but that may be naive seeing as though I don't understand the entire impact of long or medium.

Any insight is appreciated. Thank you!!
 
#2 ·
shorter cage for bikes that receive more abuse, they wont get caught up in the spokes and ruin wheels but they lack in quality of shifting, and chain tension

long cage for precise shifting and good tension keeping-you run the risk of damaging your derailleur on rocks, and in crashes, as well as the possibility of ruining your wheel, chain, dropout, and causing injuries if you do so. Better for xc bikes and road bikes etc. bikes that dont get too much thrashing
 
#3 ·
Actually, That's some bad information. It depends on the type of riding you do, and the gear ratio you are running. A long cage derailleur will allow you to use all of your gear ratios (i.e. you can shift into all 27 gear combinations if you run a 3x9 setup). However, most people do not use all of their gears. I ride XC using a shortcage der., and I give up some of my combinations (e.g. my large chainring on bothe ends). If you run very low gears, you need to use a derailleur capable of shfting into your lowest sprocket. I would recommend that you use the the derailleur that gives you the least amount of chain slap.
 
#9 ·
there was barely any aggresive riding around 9 years ago (in terms of jumping/freeride) and if you saw my derailleur after i took it off you'd know why it shifted like crap. B limit screw stripped, bent cage (long cage btw), spring didnt stay stiff very long (good or bad?) and over all it was a piece of crap after the first month no matter how much i adjusted it (didnt shift all the way to gear 9 no matter what, even if i loosened the high adjustment screw all the way) and it would hit my spokes causing a very annoying rattling (yes i adjusted it but it was either gear 8 being the lowest, or deal with the sound). But it was great for a month or two!
 
#10 ·
potvinwannab said:
shorter cage for bikes that receive more abuse, they wont get caught up in the spokes and ruin wheels but they lack in quality of shifting, and chain tension

long cage for precise shifting and good tension keeping-you run the risk of damaging your derailleur on rocks, and in crashes, as well as the possibility of ruining your wheel, chain, dropout, and causing injuries if you do so. Better for xc bikes and road bikes etc. bikes that dont get too much thrashing
Uh.

Long cage is for bikes running triple so it can go into all of the gears and dealing with the extra chain length. Also for suspension bikes that experience big chaingrowth. If you run a short or mid cage on a suspension bike with multiple front rings you can risk breaking the chain if your frame experiences chaingrowth on compression while in the larger cogs on the cassette. Has nothing to do with shift quality.

Short/Mid Cage works well on bikes that do not have huge gear ranges. DH single or double setups and bikes with close ratio cassettes. Shorter cages will obviously keep out of rocks and be better protected. They also weigh less, less chain and less cage.

Whatever you do when selecting a derailleur make sure you check the chain in the big - big combo to make sure your derailleur has the range to get there. This is expecially important for FS bikes, compess the suspension all the way when checking the chainlength. Broken chains and derailleurs are no fun.
 
#12 ·
potvinwannab said:
seriously? my last derailleur didnt shift into certain gears and i thought it was because of bad tuning. It was a long cage too. Never experience a ghost shift though
Also, check your derailleur hanger. I just went through that with mine. When I upgraded to 9 speed it clicked and rattled around (it only did that if the old 8 speed was really dirty). It looked straight and when I pulled it off it was just barely bent -- but with no other changes -- it shifted great with the new hanger.

mbb
 
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