tsappenfield

Doing a restore on a 10-speed, 1983 Schwinn World curbside find with stem mounted friction shifters. This bike has Shimano components. After a thorough cleaning, degreasing, new cables and housing, the following problem. The rear derailleur works fine, but the front derailleur will not move the chain onto the large chainring. I can't even move it out far enough by hand. The chage is not bent, it is aligned vertically and horizontally and adjusting either or both limit screws doesn't help. What to try now or is it time for a new derailleur?
Tsapp

Andrew R Stewart 

First you need to determine if the der is limited in it's movement by something like the limit screw, an easily played with part. If so, and if the limit screw(s) are not rusted in place, they will allow more or less cage movement when turned. If the screws are not the limiting factor and if the parallelogram is completely extended then perhaps the rings are too fay away. As in too long a Bb axle?


This is one more example of no photos being our limiter. Andy

maddog34

does the crank set look exactly like this one(ignore cosmetics)?
https://oldtenspeedgallery.com/blog/w...d-sport-05.jpg

bikeman715

I am with Andrew on this one , sounds like the BB's axle is too long . Maybe it was replace sometime during the life of the bike .

sunburst

I struggled with the opposite problem for days (or was it weeks?) and decided the BB spindle was too short. The bike also was an unknown quantity that was given to me. It may have never worked for all I know, at least not with the components that were on there. A big clue was that two FDs were clamped to the seat tube when I got it. I tried - in vain - to get either of those, plus two or three of my own to shift to the small chainring.

The next step is to find a longer spindle.

grizzly59

Maybe you have the correct spindle, and it was installed backwards. Look at the distance from the outside of the chain stay to the inside of the crank arm where the pedal attaches. Is the left side approximately the same distance as the right side?

tsappenfield

The crankset is by Sistar. Both limiting screws function. I rebuilt the bottom bracket and I know that I inserted the longer end of the spindle on the drive side. Also, I might add that the front derailleur wouldn't engage the large chainring when I first brought this curbside find home. Too long of a spindle is a possibility.
Tsapp

grizzly59

Maybe you have the original BB installed correctly, and the original crank was wrecked. The crank you have could have been pulled out of a parts bin and bolted on. And it has different specs than the original, doesn't match up with the given BB for a proper chain line. Can you measure the chain line of the crankset as installed?

https://www.sheldonbrown.com/chainline.html

HillRider

Try reversing the spindle anyway.

I used to have an early-'90's Trek MTB that had a Tange cup-and-cone square taper bottom bracket. When I first overhauled it I was shocked to find the spindle had been installed "backwards" from the factory. So, I installed it "correctly" only to find the crank was too far outboard and the nds-drive side crank arm hit the nds chainstay. "Backwards" was correct in this case.

tsappenfield

All is well. Turns out that I just hadn't turned the L limit screw out far enough. Took the bike out for a test ride and I can get into all gear combinations with no chain rub and without the chain falling off the chain rings. Kind of embarrassing to tell the truth. Thanks to all who offered suggestions.
Tsapp

sunburst

I ran into this problem also!