msl109

Hello folks - wondering if anyone else is having an issue with the limit screw springs on an '88 Chorus rear derailleur (gen 1) preventing me from restricting travel over a freewheel - I had to remove the springs to give me enough cage travel for a 6 or 7s. I could have cut the springs in half but feared I would just render them useless by reducing tension on the screwhead too much. I'd experiment if I knew where to source these springs - online, I'm seeing prices of $20+ for two little springs - seems like a ridiculous markup. Any ideas? Thought I once read another post regarding this issue with this derailleur but can't find it. Thanks for your help, as always

Btw, the bike is an '86 (I think) Pinarello Montello and the wheelset worked fine on the bike it was previously on, don't think it's a dish problem. .

FBinNY 

I don't understand this at all.

The springs are under the heads, so they would prevent the screw from going in farther, and so the springs could prevent you from RESTRICTING the travel range, but they can't prevent you from extending it.

OTOH - it's possible that you are describing the problem backward, and mean you need to remove or cut the spring to restrict the travel for use on narrower freewheels. In that case, it is possible, and cutting the spring is one option. improvise a cap for the business end of the screw to make it a bit longer.

Chombi1 

I have it on my Pinarello with a six speed Regina America FW and although the system shifts very well for me, the low gear limiting screw is bottomed out and just barely keeps the derailleur cage from hitting the spokes.... I'm thinking of maybe snipping off a couple of the coils from the end of the spring to let the limiting screw screw into the derailleur arm just a little bit more so I'm sure not to have the wheel eat up my Chorus RD....... Much easier to do than trying to find just the right length replacement (longer) screw.

msl109

You're right, I misspoke. Have corrected it - springs are preventing me from restricting travel.
I had thought of using a longer screw.

FBinNY 

A longer screw is an option, but I've never found any that match the thread. The simple fact is that derailleurs are designed around the freewheel/cassette widths of their era, and it can be problematic to refit them for another era. You just need to be creative.

msl109

I imagine this was designed for a 7 or 8s, surprised I can't limit it enough for a 6. But I realize there are other variables.
No one knows or has measured the thread on these screws? I don't have a thread pitch tool and I doubt local hardware places will either.

Hate to cut the springs, not knowing where to get replacements. Guess improvising some kind of cap at the end of the screw is the best option.

jiangshi

Check alignment of the RD hanger. It should shift a 6s with no issues. Is this an A-B RD?

FBinNY 

Keep in mind that there's significant variation in the offset of the derailleur with respect to the freewheel or cassette. I see many freewheels on hubs with longer axles riding more inboard than necessary. Add the thicker dropouts on modern frames vs. older ones and the position of the RD vs. The freewheel can vary by more than a few mm.

So it's not only a question of a narrower travel range. It's also that it can be biased to one side or the other, creating a situation where one limit is OK, but one way too short.

Lastly, there's also the possibility that the arc of travel may cause the extended limit screw to miss it's target.

msl109

Yes, it's an A-B. Set on the wider tooth range setting. My issue is it won't limit enough. It shifts over the range fine.

msl109

Makes a lot of sense.