9 speed rear derailleur on 7 speed cassette?
08-28-06 | 08:59 PM
#1
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From: New York
Bikes: Cannondale M300
9 speed rear derailleur on 7 speed cassette?
I'm planning to buy a new shimano xt rear derailleur soon. My question is will a 8/9 speed rear derailleur works with my 7 speed cassette/shifters? I think i read somewhere that it will work but just want to be sure 
Thanks
John
Thanks
John
08-28-06 | 09:09 PM
#2
Gone, but not forgotten
Joined: Jul 2002
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From: Newtonville, Massachusetts
Bikes: See: https://sheldonbrown.org/bicycles
Originally Posted by JNG330
I'm planning to buy a new shimano xt rear derailleur soon. My question is will a 8/9 speed rear derailleur works with my 7 speed cassette/shifters? I think i read somewhere that it will work but just want to be sure
See also: https://sheldonbrown.com/speeds
Sheldon "No Problemo" Brown
08-28-06 | 09:12 PM
#3
Which is to say, all Shimano rear deraillers designed for indexed shifting have the same cable-pull ratio. (Excepting pre-9-speed Dura-Ace, which probably isn't your worry.) So you could use a 105 rear derailler originally from a 6-speed gruppo, with 9-speed cassette and shifters. I've done this and it works fine. You could also go the other direction.
This isn't nearly so clean with Campagnolo, fyi.
This isn't nearly so clean with Campagnolo, fyi.
__________________
"c" is not a unit that measures tire width
"c" is not a unit that measures tire width
08-28-06 | 10:17 PM
#5
Originally Posted by JNG330
So that goes for SRAM ESP derailleur also? Just have to use it with SRAM ESP Shifter or can throw in shimano stx shifter?
08-29-06 | 03:43 AM
#6
Cletus Awreetus-Awrightus
Joined: Jul 2004
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Tim is correct, ESP does not use Shimano's 1:2 standard. From SRAM at:
https://www.sram.com/en/service/sram/...27a0c99bff6710
https://www.sram.com/en/service/sram/...27a0c99bff6710
Q.What's the deal with different actuation ratios?
A.Well, SRAM's ESP design uses a 1:1 ratio. This means that for each millimeter of cable moved in the shifter, an equal millimeter will be moved in the derailleur. This allows a greater acceptance of off-road conditions (dirt, water, sand, etc.) and also gives SRAM a unique shifting technology. Conversely, Shimano uses a 1:2 ratio for it's shifting systems. This means that for every one millimeter of movement in the cable there will be two millimeters of corresponding movement in the rear derailleur. The ratios are not the same; therefore, you cannot use an ESP shifter and a Shimano derailleur, or vice versa.
A.Well, SRAM's ESP design uses a 1:1 ratio. This means that for each millimeter of cable moved in the shifter, an equal millimeter will be moved in the derailleur. This allows a greater acceptance of off-road conditions (dirt, water, sand, etc.) and also gives SRAM a unique shifting technology. Conversely, Shimano uses a 1:2 ratio for it's shifting systems. This means that for every one millimeter of movement in the cable there will be two millimeters of corresponding movement in the rear derailleur. The ratios are not the same; therefore, you cannot use an ESP shifter and a Shimano derailleur, or vice versa.
08-29-06 | 03:56 PM
#8
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From: New York
Bikes: Cannondale M300
So im guessing the SRAM shifting method is more accurate and faster?? My bro just brought a SRAM attack shifter and he said its compatible with shimano derailleur. It is a awesome shifter, can be downshift a few times by pushing the trigger down harder. It is too bad for me tho cause i got a 7 speed bike and there isnt any good shifter out there for that 
10-25-17 | 11:47 PM
#9
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I'm planning to buy a new shimano 9s shifter and chain 9s cogs, and my shimano tourney 7s rear derailleur still working. My question is it compatible to speed rear derailleur with my 7 speed? I think i read somewhere that it will work but just want to be sure.
Also have a problem with chains get slipping
Thanks
Also have a problem with chains get slipping
Thanks
10-26-17 | 02:46 AM
#10
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Joined: Mar 2008
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I'm planning to buy a new shimano 9s shifter and chain 9s cogs, and my shimano tourney 7s rear derailleur still working. My question is it compatible to speed rear derailleur with my 7 speed? I think i read somewhere that it will work but just want to be sure.
Also have a problem with chains get slipping
Thanks
Also have a problem with chains get slipping
Thanks
A new chain and cassette may cure the chain slip problem.
A 9-speed cassette won’t fit on a 7-speed freehub body.
