Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

Is this rear derailleur ok?

Notices
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.

Is this rear derailleur ok?

Old 08-27-12, 09:57 PM
  #1  
Senior Member
Thread Starter
 
Bahnzo's Avatar
 
Join Date: Jun 2012
Location: Loveland, CO
Posts: 313

Bikes: 1986 Schwinn Passage, 2006 Giant OCR3

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 58 Post(s)
Liked 3 Times in 1 Post
Is this rear derailleur ok?

I've noticed that when in the two lower gears, the derailleur seems to "sit" on the gears. Not sure if this is something I need to look into or what?

Attached Images
File Type: jpg
RearDerail.jpg (97.3 KB, 83 views)
Bahnzo is offline  
Old 08-28-12, 02:11 AM
  #2  
Senior Member
 
Join Date: Mar 2008
Posts: 8,688
Mentioned: 46 Post(s)
Tagged: 0 Thread(s)
Quoted: 1074 Post(s)
Liked 295 Times in 222 Posts
There's probably a way to fix that, it's called b-screw adjustment; https://www.parktool.com/blog/repair-...nts-derailleur , https://sheldonbrown.com/derailer-adjustment.html , https://www.google.com/search?hl=sv&...nt&safe=active
dabac is offline  
Old 08-28-12, 04:13 AM
  #3  
bike whisperer
 
Kimmo's Avatar
 
Join Date: Dec 2009
Location: Melbourne, Oz
Posts: 9,537

Bikes: https://weightweenies.starbike.com/forum/viewtopic.php?f=10&t=152015&p=1404231

Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 1523 Post(s)
Liked 716 Times in 508 Posts
No B-screw on that derailleur...

Should prolly get a better one.
Kimmo is offline  
Old 08-28-12, 10:14 AM
  #4  
Member
 
Join Date: Aug 2012
Posts: 36
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
While we're on this topic, is there any way to adjust the pulley position on a rear derailleur that has no B-screw? Removing links? Shims?
AlabamaCommuter is offline  
Old 08-28-12, 10:25 AM
  #5  
Senior Member
 
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 38,647

Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter

Mentioned: 140 Post(s)
Tagged: 1 Thread(s)
Quoted: 5756 Post(s)
Liked 2,524 Times in 1,395 Posts
Take a careful look at the photo, and see that the stop cam hasn't come up to the stop on the hanger. That means that there's nothing keeping the RD from coming forward more. Odds are that the opposite tab on the stop cam is either sheered off, or the cam is mispositioned on the RD, so it isn't doing anything to set the angel.
Pull the RD off, and look for a tab engaging the cam to the RD, If it's sheered off you need to replace the cam. If there is a tab or other stop, but it's in the wrong place, you should be able to remove and rotate the cam so it works properly when remounted.

So it's either a 1 minute repair, or you're probably SOL
__________________
FB
Chain-L site

An ounce of diagnosis is worth a pound of cure.

Just because I'm tired of arguing, doesn't mean you're right.

“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FBinNY is offline  
Old 08-28-12, 10:38 AM
  #6  
Senior Member
 
Chombi's Avatar
 
Join Date: Jul 2009
Posts: 11,128

Bikes: 1986 Alan Record Carbonio, 1985 Vitus Plus Carbone 7, 1984 Peugeot PSV, 1972 Line Seeker, 1986(est.) Medici Aerodynamic (Project), 1985(est.) Peugeot PY10FC

Mentioned: 22 Post(s)
Tagged: 0 Thread(s)
Quoted: 150 Post(s)
Likes: 0
Liked 34 Times in 27 Posts
There definitely something wring with maybe the way the derailleur was installed as that Huret rear derailleur should easily be able to handle those big low gear cogs with no problem. Forum members with the same or similar Huret RDs on their bikes should be able to help as soon a they start chiming into this thread. Try changing the thread title to something that mentions "Huret rear derailleur" on it to snag those guys into this discussion.

Chombi
Chombi is offline  
Old 08-28-12, 02:43 PM
  #7  
Old fart
 
JohnDThompson's Avatar
 
Join Date: Nov 2004
Location: Appleton WI
Posts: 24,773

Bikes: Several, mostly not name brands.

Mentioned: 153 Post(s)
Tagged: 0 Thread(s)
Quoted: 3580 Post(s)
Liked 3,393 Times in 1,927 Posts
Huret did offer a version of the mounting plate that allowed "B-screw" adjustment:



Unfortunately, they're rare as hen's teeth these days.

Is it possible the OP is using the wrong mounting plate for the dropout, i.e. a Huret plate on a Campy-type dropout or vice-versa?

More pictures would help, like a straight-on side view to see the "angle of the dangle."
JohnDThompson is offline  
Old 08-28-12, 04:36 PM
  #8  
Senior Member
Thread Starter
 
Bahnzo's Avatar
 
Join Date: Jun 2012
Location: Loveland, CO
Posts: 313

Bikes: 1986 Schwinn Passage, 2006 Giant OCR3

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 58 Post(s)
Liked 3 Times in 1 Post
Ok, I'm still pretty new so I'm still trying to get up to speed on terminology. It is correct there is no B-screw. However, the two pulley's do seem like they can be moved up and away from the gears, there's just nothing to set or adjust to keep them there.

I got this bike from a guy who had it hanging in his garage for years, so I haven't changed or replaced anything, and I didn't get the impression the guy did much of anything either.

I'll try to get some more pics, taken outside, later on if possible.
Bahnzo is offline  
Old 08-28-12, 04:51 PM
  #9  
Senior Member
 
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 38,647

Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter

Mentioned: 140 Post(s)
Tagged: 1 Thread(s)
Quoted: 5756 Post(s)
Liked 2,524 Times in 1,395 Posts
You don't need new pictures. Re-read my earlier post, and look at your fist photo, or at the bike itself.

You'll see that the stop plate's tab isn't engaging the stop position on the hanger, and so is doing nothing to keep the RD from angling farther forward.

There are a few possibilities,

1- everything on the RD is OK, but the stop plate is made for a different hanger as John suggested
2- it's the wrong stop plate for this RD, or mounted wrong so the tab is in the wrong place
3- the corresponding part of the plate that engages the RD is broken off, making the plate useless for setting the angle of the RD.

Another possibility exists. Some RDs of that era had springs in the upper body, that pulled them back with regard to the hanger (or stop cam). Offhand I don't know if your RD is one of these, but if so one leg of that spring is either broken off or dislodged.

If you do post more photos, remove the RD and post one showing the stop plate and upper body from the stop plate side.
__________________
FB
Chain-L site

An ounce of diagnosis is worth a pound of cure.

Just because I'm tired of arguing, doesn't mean you're right.

“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FBinNY is offline  
Old 08-28-12, 06:39 PM
  #10  
Senior Member
Thread Starter
 
Bahnzo's Avatar
 
Join Date: Jun 2012
Location: Loveland, CO
Posts: 313

Bikes: 1986 Schwinn Passage, 2006 Giant OCR3

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 58 Post(s)
Liked 3 Times in 1 Post
Ok here's something I found:

This was one of the best derailleurs of the time - early ‘80s. The paralellogram was horizontal, but the cage moved on a second unsprung parallelogram to let it cope with a very large range of sprockets. This is the steel Eco version - the original Duopar was titanium...
This seems to explain exactly what I'm seeing. There is one spring on there which keeps the two pulleys vertical (if I unhook the spring, they fold back on themselves). The other way the pulleys move, isn't sprung...the unsprung from the quote above...so it seems to me it's meant to do this.

Edit: I also found a page here that talks about it. THIS post in particular seems to also mention that maybe I'm just being paranoid and the way the RD hangs is how it was meant to be.

Last edited by Bahnzo; 08-28-12 at 07:24 PM.
Bahnzo is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
trail_monkey
Bicycle Mechanics
0
09-09-18 01:03 PM
Chainlynx
Bicycle Mechanics
6
09-23-14 07:14 PM
Savagewolf
Bicycle Mechanics
0
06-22-12 11:44 PM
fuji_owner
Road Cycling
13
05-16-12 10:17 PM
b dub
Classic & Vintage
16
01-25-10 03:11 PM

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.