which rear derailleur?
06-08-08, 03:22 PM
#1
Junior Member
Thread Starter
Join Date: Jun 2008
Posts: 7
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
which rear derailleur?
I have a fairly old bike with Shimano Altus A20 components, and the rear derailleur broke. Can I just get a similar sized Shimano derailleur that is made for the same number of gears? I am thinking about replacing the rear derailleur with a Shimano Alivio.
06-08-08, 04:03 PM
#3
Senior Member
Join Date: Jul 2007
Location: Maryland
Posts: 136
Bikes: Bridgestone '90 RB-1, Giant TCR Alloy, 90's mountain bikes galore.
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
You can put a new rear derailleur on as long as it's for a 7/8 speed. I'm not positive, but I think there could be issues if you used a 9 speed since the pulleys and chain widths are different. If you're not using a chain with quick disconnect/power links, you'll need to replace the chain or buy replacement pins.
Here's a good deal on a rear derailleur: https://www.nashbar.com/profile.cfm?c...%20Derailleurs
Here's a good deal on a rear derailleur: https://www.nashbar.com/profile.cfm?c...%20Derailleurs
06-08-08, 06:29 PM
#4
Senior Member
Join Date: Jul 2002
Posts: 6,956
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 6 Times
in
5 Posts
Also view the bike from the rear after attaching the rear derailleur, and check whether the frame's derailleur mount is out of alignment. If it is, you want to get it aligned so your new derailleur doesn't get wrecked (hooked in the spokes when shifting to low gear, for example).
Aligning the derailleur hanger can be done by your LBS the "proper" way, or you can usually do a reasonable job with some careful use of a large adjustable wrench. If the hanger is significantly damaged, thread the bolt from the old derailleur back into the hole before you start aligning the hanger, so the bolt keeps the hole from getting too deformed to install your new derailleur into it.
Disclaimer: you can ruin your frame if it does not have a removable/replaceable derailleur hanger and you're unlucky or uncareful. So if you're not sure on this task, hand it off to the LBS.
Aligning the derailleur hanger can be done by your LBS the "proper" way, or you can usually do a reasonable job with some careful use of a large adjustable wrench. If the hanger is significantly damaged, thread the bolt from the old derailleur back into the hole before you start aligning the hanger, so the bolt keeps the hole from getting too deformed to install your new derailleur into it.
Disclaimer: you can ruin your frame if it does not have a removable/replaceable derailleur hanger and you're unlucky or uncareful. So if you're not sure on this task, hand it off to the LBS.
06-08-08, 08:22 PM
#5
Senior Member
Join Date: Jul 2005
Posts: 7,487
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 140 Post(s)
Liked 163 Times
in
89 Posts
Whether the rear derailleur is designated seven speed, eight speed, nine speed doesn't matter, it will work. But you're right about the chain, to run nine speeds would require the narrower nine speed chain-
06-08-08, 09:54 PM
#6
Insane Bicycle Mechanic
Join Date: Mar 2008
Location: other Vancouver
Posts: 9,843
Mentioned: 34 Post(s)
Tagged: 0 Thread(s)
Quoted: 809 Post(s)
Liked 711 Times
in
379 Posts
Replacing an Altus with an Alivio is no problem. They are 100% compatible.
__________________
Jeff Wills
Comcast nuked my web page. It will return soon..
Jeff Wills
Comcast nuked my web page. It will return soon..
06-08-08, 10:41 PM
#7
use your best eye
Join Date: Mar 2006
Location: Olympia, Washington
Posts: 3,050
Bikes: '75 Bertin, '93 Parkpre Team 925, '04 Kona King Kikapu, '05 Bianchi Vigorelli
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
+1. Go for the Nashbar deal- for $14.99 you can't go wrong.
__________________
"I tell you, We are here on earth to fart around, and don't let anybody tell you any different." - Kurt Vonnegut jr.
"I tell you, We are here on earth to fart around, and don't let anybody tell you any different." - Kurt Vonnegut jr.
