SB_Greg

Im cleaning up a Campy Gran Sport rear derailleur froma 1960 Carolton Franco Suisse. I have it all dissasembled except for the bolt holding the rear assembly together. See my photos. Should the bolt with my allen wrench inserted simply unscrew? Ive had it soaking in solvent and it wont budge. I am afraid to apply much more pressure until I know what is what.


Here is where I am at. This bolt wont budge!

Photo of the back.

before dissasembly

1simplexnut 

Its just my opinion but would leave it well alone :-) But what do i know.
Got any any pics of the Carlton ?

iab

Yes. It should unscrew.

See the 3 concentric holes on the backside? Those are for adjusting the jockey arm spring. You get access to it and adjustments by removing said bolt.

SB_Greg

thats what I thought. I’ll add a bit more oomph to the wrenching. Thanks!

Piff 

Glenn's Manual dump incoming.

Piff 

Piff 

lostarchitect 

Dang, that is awesome, Piff!

Piff 

My Uncle very kindly gifted me a copy of Glenn's when I really started getting into old bikes. It's such a great book and so cheap on ebay!

SB_Greg

extremely useful. Thanks!

merziac

Sounds like you probably have it sorted now but one thing I always do is try and hold the cage tight in a neutral position, if the bolt is tight like yours and you turn against a stop it can screw things up.

SurferRosa

On this Nuovo Record schematic, you're trying to free part 811/A, the tension spring bolt.




For NR derailleurs, the grub screw (812/1A) is removed first before any disassembly. And, when assembling, the cage is wound before the grub screw is replaced. Makes it so much easier. It's a little more difficult with Gran Sport and Record. When putting it back together, you have to thread the spring bolt a little bit, wind the cage (working it around the fixed grub screw) and then finish tightening down the bolt.

So, when you do free that stuck bolt, you may wish to loosen it short of all the way and unwind the cage before completely removing the bolt. If you don't, be ready for the spring and cage to snap on you.

xiaoman1 

Agreed...very good information, is it "Glen's" repair manual that you are referencing..at 5 bucks it seems well worth the price of admission?
Ben

Piff 

I think there are multiple editions, but I have this one:

steve sumner

the main bolt won't unscrew until you've taken the tension off it by removing the
stop screw that lets the spring unwind.

SurferRosa

Not true. But if the cage can be unwound first, it makes things easier.

xiaoman1 

piff,
thanks, just bought it.....less than 5 including free shipping...worth it just for the campy pics.
ben

Road Fan

I would say, yes it should unscrew, and I have one that I recall I did unscrew many moons ago. But is there a reason you need to? The parts are 70 years old. If it turns freely and reasonably smooth, the spring wind up and springs, and ... there isn't a lot of wiggle or play, let it stay as it is.

SB_Greg

This was a fun little project. The diagrams really helped. Truly the best advice I received was to leave the back bolt in place.

allenre

I am using a Gran Sport on a 5-speed Regina freewheel on my newly restored 1951 Gillott but am having trouble with the Campag as it keeps jumping out of gear and always climbs down to the smallest sprocket as soon as I start pedaling. I am using a lever with a high-friction return but that hasn’t helped. It seems like the return spring is applying too much force for the lever to hold against but I can’t see any way to adjust that. Can anyone out there offer any advice or tell me whether it is possible to adjust the rear mech somehow?

John E

Your problem is in your gear lever, not your derailleur. Something either with a small capstan (e.g. original Campag. or Simplex) or alternatively with a ratchet (SunTour barcons or ratcheting stem shifters) may help. Are you sure you have assembled all of the internal friction parts of your shifter properly?

allenre

Many thanks, John. I can't comment on the assembly of the shifter as it was done by someone else who restored the bike but he's quite experienced so I would trust him to have done it correctly. Certainly I can't tighten the screw any further without damaging it. I had rebuilt the bike myself approx. 40 years ago and used a then-current Shimano rear mech with the original Simplex lever and that worked perfectly. For the recent restoration, we have tried to return it to near-original spec. hence the Campag and used that same Simplex lever but the latter didn't appear to be strong enough this time around. So we swapped it for the retrofriction type lever which looks pretty much identical although not an actual Simplex: no branding is marked on it. It worked at first but only for a short while. I'll look into ratcheting types as that sounds like an excellent suggestion but I'll discuss with the restorer before changing anything.

smd4

Thanks for the tip! I'd never heard of it. My copy is on the way...

repechage

test, don't guess.

3alarmer

...not sure what you are calling "retrofriction levers" ? The Simplex retrofrictions are almost impossible to assemble incorrectly, and work well with everything, including Campy derailleurs. I'm using that setup now on a couple of bikes. They are adjustable, in terms of how firmly they hold position, but it seems like you've attempted that. If your guy does restorations, he ought to be of some help.