67walkon

I picked up an old, 1973 Schwinn Varsity, took it apart down to the frame, cleaned and re-lubed bearings in the crank and headeset, cleaned it up and put it back together. I've got new tires, new cables, new brake pads and lots of newly shiny chrome. It was an exercise I enjoyed immensely and I think it will help me maintain my modern road bike.

The front derailleur is missing the bolt or roller that would go through the back of it, on the back end, closest to the back wheel. On my other bikes, it is either solid there or there is a roller or something. Other than operating as a spacer between the 2 sides of the front derailleur apart, it doesn't seem to do much--if adjusted properly, I don't the chains on my other bikes actuall hit it.

What is the purpose of that part? If I just go to my ACE Hardware store and put a shiny bolt or maybe something with a roller on it, will that work? Or should I just leave it or maybe be on the lookout for another junked Varsity?

Is it dangerous to ride without it? I can't see how it would be, but other than changing tires and chains on my Specialized bike, this is my first adventure into serious bike wrenching.

Thanks, John

demoncyclist

Just find a bushing the right length. It merely holds the two sides of the derailleur cage apart the proper distance. A bolt and nut (and a dab of loctite so it doesn't fall out again) will complete the rebuild.

corynardin

A picture would be helpful.

FBinNY 

The only purpose of the spacer on the cage bolt is to keep the bottom of the plates correctly spaced with the bolt tight. Without it, you couldn't tighten the bolt. Use anything to take up the space, and any screw and bolt of the right length. A stack of washers is as good as anything for the job.

BTW- modern cages don't use this design, they usually extend the outer cage, fold it 90 degrees and rivet it to the inner.

HillRider

That's not quite right. All of the more recent Shimano and Campy front derailleurs I have (7-speed and newer) do indeed bend the tail of the outer cage into a U-shape instead of using a spacer and through bolt but they bolt the inside of the U to the inner cage plate.

Even with this design you can still remove or replace a front derailleur with out cutting the chain. You remove the bolt, carefully spread the cage sides apart and slip the chain through the gap. Done carefully it does not bend or distort the derailleur's cage.

FBinNY 

Yes, your description was more precise than mine. I was only making the point that there was no functional purpose to the roller shape at the bottom of the cage, since the chain doesn't roll on it (or isn't supposed to).