I am posting this everywhere I can think and I am getting a bit desperate.

I am putting the final touches on my winter build and I am having a problem with the front derailleur. There is rub on the outside cage plate when the chain is on the big ring.

The derailleur is a Cyclo Rosa, identical to the one seen here:




The bike it is going on is a 1955-1960 Cinelli Model B. The chainrings are 50/47 on a cottered, 3-arm crank marked "Lightweight" (there is no other brand). The chain is a 3/32" Regina Extra.

My derailleur is not original to the bike but the previous owner said is is the same make and model as the original.

Is there any way get the high-gear limit stop to extend a bit further, 1-2mm on this derailleur? The two adjustment bolts on the back seem to control the friction of the lever. And of course, I would prefer not to bend the cage.

These very old derailleurs are new to me and I don't want to chance damaging anything. Also, the LBS is not any help, they didn't even know derailleurs like this existed. Any information will be appreciated. Thank you.

I'm seeing three nuts in the second picture, and I'd imagine that loosening some if not all would allow you to move the cage along that shaft. Alternatively, I can't quite see how it mounts to your frame, and I'm wondering if you'd use a spacer of some sort to push things out bit. However, if you move the cage a couple of mm farther out, will it then rub on the other side?

Neal

Thanks for the help. What is not pictured is the clamp that mounts to the seat tube. It goes between the the two lock nuts and that odd looking nut on the outside. The spacer (washers) should work between the the lock nuts and the seat post clamp. The lock nuts hold the helical cam mechanism (you are right dafydd) in place, if I move them out, the mechanism gets loose.

But the spacer should push the whole mechanism out. It's late and I am tired so this will have to wait until Saturday. I will post results then.

Also, since it was rubbing on the big ring, I never moved it to the small ring. I just did and it pushed the chain off the small ring, moving it out with the spacer should remedy that problem too.

Could your BB spindle possibly be too long for this FD? I ran into this problem in a project I'm working on with an early '60s vintage cable operated FD. I did have the luxury to decrease the overall BB width which moved the chainrings inward and this made it work. I'm not certain this is an option with cottered cranks. Good luck.

With 3-bolt cottered cranks it is a simple matter to move the chainrings inboard with washers.

Ahhh, the sweet smell of success. Two modified washers and it shifts like a dream, thanks everyone for your help.