NEED REAR DERAILER HELP

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Rat Rod

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When I bought this bike the rear derailer was acting weird.

The lowest tensioner wheel kept flying upward and causing the chain to go slack and nearly fall off.

It appears that someone replaced the rear derailer cable at some point.

I removed the chain to clean it up and wondered if anyone was a rear derailer nerd here and could help me understand how to set this thing up correctly.

IMG_2303.jpg


IMG_2294.jpg


Here's what my shifters look like.

IMG_2300.jpg
 
I would guess the cable was not properly tensioned, but you may have a different issue. Most derailer' s don't hang like that when the chain is removed. The spring should compress and the derailler sucks up into itself. A spring might have broke or become unanchored.
images


Here is a good tutorial anyhow.
http://www.parktool.com/repair/readhowto.asp?id=64
 
Well you have an older suntour derailleur,theses were known for not working properly. the shifters are excellent tho.

1 with the chain off, ajust the small gear limit screw
2 push the derailleur with your finger and check the big gear limit screw.
3 reinstall the cable and chain . make sure the cable is tensionned when on the smaller gear.
4 test drive.

from the look of it, the lower spring/bolt that tension the cage seems wrong, you have to take the little limit screw off and turn the cage 360 degrees(to put more tension in the spring) and then put back the limit screw.

if that dont work, put any shimano derailleur with the sme shifters and it will work fine.
 
tartosuc said:
Well you have an older suntour derailleur,theses were known for not working properly. the shifters are excellent tho.

1 with the chain off, ajust the small gear limit screw
2 push the derailleur with your finger and check the big gear limit screw.
3 reinstall the cable and chain . make sure the cable is tensionned when on the smaller gear.
4 test drive.

from the look of it, the lower spring/bolt that tension the cage seems wrong, you have to take the little limit screw off and turn the cage 360 degrees(to put more tension in the spring) and then put back the limit screw.

if that dont work, put any shimano derailleur with the sme shifters and it will work fine.
boo on the shimano advice!
stick with the suntour (friction-shift all the way!)
 
new_dharma said:
tartosuc said:
Well you have an older suntour derailleur,theses were known for not working properly. the shifters are excellent tho.

1 with the chain off, ajust the small gear limit screw
2 push the derailleur with your finger and check the big gear limit screw.
3 reinstall the cable and chain . make sure the cable is tensionned when on the smaller gear.
4 test drive.

from the look of it, the lower spring/bolt that tension the cage seems wrong, you have to take the little limit screw off and turn the cage 360 degrees(to put more tension in the spring) and then put back the limit screw.

if that dont work, put any shimano derailleur with the sme shifters and it will work fine.
boo on the shimano advice!
stick with the suntour (friction-shift all the way
!)

Did i say anything about friction or indexed shifting?


You can go on friction with either shimano or suntour. that particular model of suntour nerver ever worked properly,there were good and bad suntours back then, this one was a bad one, we were switching thoses all the time back when I was was working in a shop...if you look a this one something is wrong with the cage tension. you can use any other suntour, shimano campagnolo if you want it will work fine with thoses shifters. but that particular one is a problematic one. I would have tought that someone with a bicycle shop would know that...
 
I'm planning to drop the bike off at my LBS today to see what they think.

They usually have lots of old stuff around so they may end up having a period correct derailleur that will work.

It's either that or have them install a single speed freewheel and ditch the gears altogether. :shock:
 
Mitch at Bicycle Exchange in Carrollton hooked me up today.

Turns out the old derailleur's spring was trashed.

He happened to have an NOS Sachs Huret model stashed away and he even installed and adjusted it while I waited.

Now she's running smooth a silk.

Will post photos later. :mrgreen:
 
tartosuc said:
new_dharma said:
tartosuc said:
Well you have an older suntour derailleur,theses were known for not working properly. the shifters are excellent tho.

1 with the chain off, ajust the small gear limit screw
2 push the derailleur with your finger and check the big gear limit screw.
3 reinstall the cable and chain . make sure the cable is tensionned when on the smaller gear.
4 test drive.

from the look of it, the lower spring/bolt that tension the cage seems wrong, you have to take the little limit screw off and turn the cage 360 degrees(to put more tension in the spring) and then put back the limit screw.

if that dont work, put any shimano derailleur with the sme shifters and it will work fine.
boo on the shimano advice!
stick with the suntour (friction-shift all the way
!)

Did i say anything about friction or indexed shifting?


You can go on friction with either shimano or suntour. that particular model of suntour nerver ever worked properly,there were good and bad suntours back then, this one was a bad one, we were switching thoses all the time back when I was was working in a shop...if you look a this one something is wrong with the cage tension. you can use any other suntour, shimano campagnolo if you want it will work fine with thoses shifters. but that particular one is a problematic one. I would have tought that someone with a bicycle shop would know that...
you said 'any shimano derailleur with the same shifters, and some shimano won't work with friction shifters really well...i have 2 of those shifters and don't have any issues (yet) with them...knowing now the spring is bad, i'd say get a new derailleur, but I wouldn't say get a shimano (ie, "get any shimano derailleur").
As far as the shop goes, i have never had a customer bring in that derailleur (i've only seen mine)...but then there are not many shops that will rebuild a bendix automatic rear hub or SA 3-speed hubs or be able to remove Schwinn-Approved rear 5-speed gear clusters off an old Krate rim...
 
new_dharma said:
boo on the shimano advice!
stick with the suntour (friction-shift all the way
!)



I never ever seen a shimano derailleur not working ok in friction mode. maybe some wont but in a general way they will mostly work fine. (i even have an older xtr 9 speed setup in friction mode on one bike and it works perfectly)

My comment was in response to your stupid way of replying to my comment, without any fact or explanation..all you said is boo! and did not give any good inputs that would help the situation.
next time be constructive.
 
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