Suntour VGT cage spring
 

A fellow came in to the Bike Shack on Sunday for work on his bike. Pretty standard stuff, but when we started to put his rear wheel in place I found that the rear derailleur's cage spring was pushing the cage _forward_ rather than pulling it back. I pulled a different old VGT from our box o' parts to get him back on the road, so I did not dig into the derailleur to figure out what was going on. I've found this old post:

http://www.bikeforums.net/classic-vi...eded-help.html

Which has an exploded diagram showing the spring, and I also have had them apart in the past. Even so, I can't see a way for the derailleur to pull the cage in reverse. Has anyone seen anything like this?

If I have time later this week I'll pull the spring and take a look, but I will appreciate any hints on what to look for.

I never heard of the V series ever having a reverse action on the rear (although the ft is reversed form the common small ring default). Sounds to me like the cage was wound backward form the correct rotation before the stop screw was installed. Andy.

Andy, that is what I wondered as well, and I took out the stop screw (which was very hard to remove, so probably had not previously been touched.) I wound the cage a few revolutions with no change at all. My expectation is that the spring is no longer pinned to the right place inside its cylinder, but who knows!

IIRC the cage pivot bolt is threaded into the cage and the outer end has 3 slots across the end to offer 6 spring capture choices. Then a threaded cap tightens against this slotted and spring containing end. The spring is a square wire wound many times. Is it possible that the cage pivot bolt isn't really tight in the cage? The inner end of the spring had 2 holes in the der pivot body (maybe only one, it's been years...). So it's completely possible that the inner end of the spring isn't in it's hole or has broken off. But all this should be real straight forward when the der is taken apart. Andy.

I'll definitely report back once I take a look when we are next open.

Thanks, I like and ending to a story. Andy

Andy, I took the spring barrel apart and the spring had broken. Specifically, the small pin at the bottom of the barrel had snapped off. I think we have another VGT that is in sad condition, so I'll see if I can salvage the spring from that one.

Thank you!

And thank you for the follow up. Andy.