Schwinn collegiate gt100 deraileur tune

[ZbikerD]

I just cleaned up and painted a collegiate for a friend and ran new cable to the rear deraileur. I was wondering if anyone has Any tuning tips for me. It has the stick shifter on the stem. I was wondering what gear should it be in when I tighten cable and what gear should the derIleur be in? 1 or 10? How tight? It seems the derIleur isnt hanging like it should. I have pictures here to show how It is sitting. Also I tune newer deraileurs but this older one has me kinda stumped. I don't wNt to start adjusting things and throwing it way out of Wack. The lower cog is up in the cassette. I took it off and cleaned it but didn't seem like I would have done anything to affect how it sits on the cassette. Any help would be awesome.

 

[Iron Horse]

Well, two things come to mind based solely on what I can see in the pictures. number one, the derailer where it attaches to the extention arm appears to be attached wrong (too far forward), or two, the chain is too long. If that is the origional chain, I am going with mis-adjustment. Where the allen head bolt is, loosen that (with the chain off the front gear set), and rotate it toward the back of the bike until it is about 30 degrees to the frame. That should be close enough. I am mostly speculating on that, having not seen an extention piece before. Retighten. Put the chain back on, small gear up front, small gear (10) in the rear. The lever needs to be all the way forward, where most of the cable is in the sheath. Set the spring adjuster at the other end of the cable about in the middle of the threads. Pull the cable tight and tighten the nut anchoring the cable to the derailer. There should be two screws almost side by side on the derailer to adjust the derailer stops so that the chain does not fall off either end of the cassette when shifting to low gear or high gear. the little spring adjuster is to fine tune where the chain stops if you have index shifting on those shift levers. Now one thing... if the cable is a solid wire instead of the more normal multi strand wires, you can take most of what I said and throw it out the window. I have never had one of those types of derailers, and don't know a darned thing about them. I hope this helped. I know it confused the heck out of me!

 

[deorman]

I've never seen one with a mount bracket like that. :? It should be shorter, not allow the body to swing that far forward, and be marked with Schwinn script. They're not very good to start with, very limited as to range of gears and very picky about chain length. They're merely sufficiently on 5-spds with long shift handles and cable savers, on 10-spds they're a pain. :roll:

 

[ZbikerD]

Ok It's only a 5 speed.. No front deraileur. Just the 5 in back.. Not original chain.. And I am pretty positive this is how it's supposed to be mounted.. The little rear bolt behind the axle bolt is how it attaches to the frame. So it shifts from first to 4th well, but not to fifth. And back up to second from fourth but the deraileur "folds" in twords the cassetteand won't hit 1st. I will make sure the chain is the same length.. Duh!! I never thought about making sure it was.. It also doesn't seem like the springs were allowing it to move freely.. I lubed the whole thing up pretty well. I could always take it to lbs bit I like to figure this kind of stuff out by myself. With the help the knowledgeable members here. I will try the cable adjustment also with the set screw you mentioned.

 

[deorman]

See edit above, and good luck. :wink:

 

[Bendix]

I've never seen one with a mount bracket like that. :?

yeah, the hanger does look very different from stock. i suspect that puts the derailleur in an unusual position relative to the cogs.

otherwise those are simple to set (to their potential).


1- cable loose, set the derailleur high limit screw so the chain runs smoothly on the smallest cog.

2- with the shifter (a stem mounted friction unit if original) pushed all the way forward, chain still on the smallest cog, take the slack out of the cable. not piano wire tight, just no slack.

3- pull the shifter back, letting the low limit screw out until the chain runs smoothly on the biggest cog, but no further.

if the parts are all ok, that's it! (deorman, what did we do with all our spare time back in the friction 5 speed days? :mrgreen: )

if that doesn't do the trick take it to someone who has experience going to plan B and beyond with old derailleurs. i really do suspect that derailleur hanger bracket is the root cause of any issues though.......:wink:

 

[ZbikerD]

Will do guys. Thanks for the tips. So one stupid question, forward on the shift lever moves the derailleur higher meaning 1st gear and back moves it to 5? Or am I backwards?

 

[ZbikerD]

I also am not sure anything about the hanger.. This is the way o got the bike. I really dig the shift lever but the derailleur can be replaced.. I have seen someone on rrb has a bunch for sale. But would that require a new hanger? If anyone has an idea on where I could pick up a "stock" hanger that would be awesome. Again thanks

 

[ZbikerD]

Another dumb question, what's the low limit screw on this thing? New derailleurs are easy but this thing has me baffled.

 

[deorman]

I have a 510 model here to look at and it's not quite the same, but they all work the same way. The outer (small cog) screw should be in the hole on the outer face of the body. The inner (large cog) screw should be at the end of the shifter body, attached to the same pivot arm as the cable end. Most Schwinn shifters that you see have the anchor pivot permanently attached with a mandrel pressed bushing, i.o.w. 1-pc assembly. The body must be able to swing though 40 degrees or so to work properly. Some have a simple solid stop, and some have a limit adjustment screw. Some may have a spring, I don't remember for sure. :|

 

[wilsonjw]

Attached is a page from the Schwinn Owner's Manual for a 1972 Collegiate that explains how to adjust the GT100.