Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 08-25-08, 09:15 AM   #1
burtonridr
Wanderlust
Thread Starter
 
burtonridr's Avatar
 
Join Date: Aug 2008
Location: Inland Empire
Bikes: Specialized Stumpjumper for MTB and a specialized hardrock for touring
Posts: 124
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Which Rear derailer?

I have a Trek 820 Mountain bike with a busted ESP Sram x-7 rear derailer. I have never had to replace a derailer before.... Can I replace it with any other derailer that is for 8 gears? I dont want to spend a ton fixing it, so what are my cheaper options?
burtonridr is offline   Reply With Quote
Old 08-25-08, 10:00 AM   #2
DMF 
Elitist Troglodyte
 
DMF's Avatar
 
Join Date: Jun 2006
Location: Dallas
Bikes: 03 Raleigh Professional (steel)
Posts: 6,924
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Dérailleurs don't have "speeds"; all that is handled by the shifter. You'll need to match the cage length and maximum cog size, but otherwise [see below]


Edit: Learn to check out the part number when OP gives it.
__________________
Stupidity got us into this mess - why can't it get us out?

- Will Rogers

Last edited by DMF; 08-25-08 at 10:35 AM.
DMF is offline   Reply With Quote
Old 08-25-08, 10:14 AM   #3
burtonridr
Wanderlust
Thread Starter
 
burtonridr's Avatar
 
Join Date: Aug 2008
Location: Inland Empire
Bikes: Specialized Stumpjumper for MTB and a specialized hardrock for touring
Posts: 124
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by DMF View Post
Dérailleurs don't have "speeds"; all that is handled by the shifter. You'll need to match the cage length and maximum cog size, but otherwise just about anything will work.
How do I determine the cage length and maximum cog size?
burtonridr is offline   Reply With Quote
Old 08-25-08, 10:17 AM   #4
LarDasse74
Guest
 
Join Date: Jul 2008
Location: Grid Reference, SK
Bikes: I never learned to ride a bike. It is my deepest shame.
Posts: 3,769
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
The question holds a mysterious snag - the Sram ESP derailleurs are, I think 1:1 actuation ratio and can only be replaced with another 1:1 actuation ratio derailleur - basically any SRAM MTB derailleur. A shimano (or sunrace or suntour or other) derailleur will not work as they are designed for 2:1 ratio shifters!

8 speed bikes work great with 9 speed derailleurs, though... I don't think 9 speed bikes work as well with 8 speed derailleurs.

Keep in mind I have never owned a Sram derailleur, so I am not 100% sure. A bike shop will be able to tell you if this is correct.
LarDasse74 is offline   Reply With Quote
Old 08-25-08, 10:31 AM   #5
DMF 
Elitist Troglodyte
 
DMF's Avatar
 
Join Date: Jun 2006
Location: Dallas
Bikes: 03 Raleigh Professional (steel)
Posts: 6,924
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Ooops. Right you are. Forgot about those odd-ball SRAMs. The X-7 is 1:1. Here's the link.

burton, you'll have to replace it with another 1:1. SRAM X-5 would do as well.

Are you sure the old one can't be fixed? pics?
__________________
Stupidity got us into this mess - why can't it get us out?

- Will Rogers

Last edited by DMF; 08-25-08 at 10:36 AM.
DMF is offline   Reply With Quote
Old 08-25-08, 10:44 AM   #6
burtonridr
Wanderlust
Thread Starter
 
burtonridr's Avatar
 
Join Date: Aug 2008
Location: Inland Empire
Bikes: Specialized Stumpjumper for MTB and a specialized hardrock for touring
Posts: 124
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by DMF View Post
Ooops. Right you are. Forgot about those odd-ball SRAMs. The X-7 is 1:1. Here's the link.

burton, you'll have to replace it with another 1:1. SRAM X-5 would do as well.

Are you sure the old one can't be fixed? pics?
LOL no it cant be fixed... It was crashed hard, the derailer was snapped off and bent the crap out of it


So do I need to pay attention to the cog size and cag length or can I just replace it with any SRAM with 1:1 ratio?
burtonridr is offline   Reply With Quote
Old 08-25-08, 11:03 AM   #7
burtonridr
Wanderlust
Thread Starter
 
burtonridr's Avatar
 
Join Date: Aug 2008
Location: Inland Empire
Bikes: Specialized Stumpjumper for MTB and a specialized hardrock for touring
Posts: 124
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
can I use like a shimano Altus or something? click here
burtonridr is offline   Reply With Quote
Old 08-25-08, 11:44 AM   #8
demoncyclist 
Senior Member
 
demoncyclist's Avatar
 
Join Date: Oct 2002
Location: Medway, MA
Bikes: 2011 Lynskey Sportive, 1988 Cannondale SM400
Posts: 2,689
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
No, it HAS TO BE another SRAM derailleur with a 1:1 pull ratio.
__________________
DEMON

Satanic Mechanic
STAR 3 Spinning Instructor

2011 Lynskey Sportive (Shimano Ultegra 10s)
1988 Cannondale SM400 (Suntour XC-M 7s)
demoncyclist is offline   Reply With Quote
Old 08-25-08, 11:45 AM   #9
LarDasse74
Guest
 
Join Date: Jul 2008
Location: Grid Reference, SK
Bikes: I never learned to ride a bike. It is my deepest shame.
Posts: 3,769
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by burtonridr View Post
can I use like a shimano Altus or something? click here
No you cannot use a shimano derailleur - sram ESP 1:1 shifters will not work properly AT ALL with a shimano derailleur. It'll make the derailleur move, but every Sram shift will move the derailleur approximately twice as far as you want it to, and not hit the gears correctly - your 8 speed drivetrain will turn ito a poorly functioning 4 speed (although it will probably only line up reasonably well in one of those four speeds)

If you had an X7 then an X5 or another X7 should bolt right into place - and any mtb derailleur will work on your mtb gear range ... you don't really need to worry about the specifics unless you are getting something more exotic, like a short cage derailleur, or you have done some odd modifications to your cassette.

Here's something fromt he same source:

http://www.universalcycles.com/shopp...0&category=692
LarDasse74 is offline   Reply With Quote
Old 08-25-08, 12:59 PM   #10
burtonridr
Wanderlust
Thread Starter
 
burtonridr's Avatar
 
Join Date: Aug 2008
Location: Inland Empire
Bikes: Specialized Stumpjumper for MTB and a specialized hardrock for touring
Posts: 124
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Ok thanks for the help everyone, I will go buy either the SRAM x-5 or x-7
burtonridr is offline   Reply With Quote
Old 08-25-08, 01:06 PM   #11
burtonridr
Wanderlust
Thread Starter
 
burtonridr's Avatar
 
Join Date: Aug 2008
Location: Inland Empire
Bikes: Specialized Stumpjumper for MTB and a specialized hardrock for touring
Posts: 124
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Wait, ok so will this one work?

Click Here
burtonridr is offline   Reply With Quote
Old 08-25-08, 01:21 PM   #12
LarDasse74
Guest
 
Join Date: Jul 2008
Location: Grid Reference, SK
Bikes: I never learned to ride a bike. It is my deepest shame.
Posts: 3,769
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by burtonridr View Post
Wait, ok so will this one work?

Click Here
ROTFL

"may not be exactly as pictured"

The derailleur as described will work, the picture is of a different derailleur that will not work. But if they ever have the derailleur in the picture listed for $35, let me know right away...
LarDasse74 is offline   Reply With Quote
Old 08-25-08, 01:41 PM   #13
burtonridr
Wanderlust
Thread Starter
 
burtonridr's Avatar
 
Join Date: Aug 2008
Location: Inland Empire
Bikes: Specialized Stumpjumper for MTB and a specialized hardrock for touring
Posts: 124
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by LarDasse74 View Post
ROTFL

"may not be exactly as pictured"

The derailleur as described will work, the picture is of a different derailleur that will not work. But if they ever have the derailleur in the picture listed for $35, let me know right away...
Great thanks for the help
burtonridr is offline   Reply With Quote
Old 08-25-08, 03:51 PM   #14
DMF 
Elitist Troglodyte
 
DMF's Avatar
 
Join Date: Jun 2006
Location: Dallas
Bikes: 03 Raleigh Professional (steel)
Posts: 6,924
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Btw, if it was crashed that hard the hanger (what the RD bolts to) will surely be bent. It has to be straightened (or replaced) or the new RD won't work worth a damn and might even catch in the wheel. Your LBS will have a tool to make it square, or with a little research you can do it yourself.
__________________
Stupidity got us into this mess - why can't it get us out?

- Will Rogers
DMF is offline   Reply With Quote
Old 08-25-08, 03:53 PM   #15
burtonridr
Wanderlust
Thread Starter
 
burtonridr's Avatar
 
Join Date: Aug 2008
Location: Inland Empire
Bikes: Specialized Stumpjumper for MTB and a specialized hardrock for touring
Posts: 124
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by DMF View Post
Btw, if it was crashed that hard the hanger (what the RD bolts to) will surely be bent. It has to be straightened (or replaced) or the new RD won't work worth a damn and might even catch in the wheel. Your LBS will have a tool to make it square, or with a little research you can do it yourself.
Actually.... crap the hanger might be what is broken and the derailer is bent
burtonridr is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 07:37 AM.