I had trouble with my right side 1st gen Record shifter holding the low gears even after replacing the G-springs. So I put on a later model Chorus lever…which appears to be doing exactly the same thing. I even replaced the G-springs in that lever prior to installing it, so I’m pretty confident that’s not the issue.
In the workstand I can shift down to sprocket no.8 (the biggest one,) but if I add a tiny bit more tension on the cable with my hand, it pulls out of gear from the shifter. Sprocket no.7 is almost impossible to select, when I click the lever for that position it just falls back to the next sprocket the second I release the lever. If I hold it there for a while, sometimes it will stay put, but that’s far from ideal. (I didn’t take it for a ride because it’s pissing down, so I’ll have to check tomorrow if it holds low gear while riding.)
So now that I’ve got two levers presenting similar problems, I’m wondering if there’s something else going on. Could the derailleur be requiring too much tension to move it over? If the derailleur was designed for a 7 speed (synchro II?) system, is it possible it might not work on an 8 speed system? (Internet seems to think it shouldn’t matter…but most info seemed to be Shimano-centric.)
Without actually probably reading what you wrote the first thing I’d do is check there’s no excess friction or snags in the system and that the cable is properly seated in the shifter.
1,check the derailleur hanger is straight with a proper tool.
2, I’d like lorday check for cable friction( disconnect the cable from mech and hold it in you hand with tension and click through the gears).
3, may be even take the bar tape off and recheck for friction and see if it still doesn’t shift
4,if it won’t click from a bigger cog to a smaller cog it has too much tension and if it won’t go from small to larger cog it has not got enough(wind tension barrel udjuster the way you want the chain to move).
5, if you are 100% certain the shifter is ok it may be the mech spring or the mech may be bent.
6, are they campy wheels with campy cassette? Are the spaces in the cassette all in the correct order?
7, May be try commuter or Dan they will both be great with older campy stuff.
You can test your shifter with a weight hanging off the cable it’s not hard to do so try google how to do it.
I had to do it to my old SR11 mechanical group turned out my main derailleur bushing was worn out and sloppy so I could get it to hold gear properly.
Let me know how you go if you get stuck I could try have a look at some point hopefully you can get it running nice.
I’ll work through the list, but these are my initial thoughts -
I’m pretty sure the hanger is straight because I bent it last year and WTP straightened it up for me. Nevertheless, I’ll double check it.
Yeah, bar tape is off. I did check the cables were seated in the shifter properly because the Chorus lever needed a bit more length of housing to get there - which stuffed up my beautiful cable routing job!
I can’t seem to get consistent results by adjusting the barrels.
Yeah, Campy wheels, Campy cassette. Will have to check the spaces - shouldn’t they be 5mm all the way up?
Will try to find that weight test, cheers.
Would it be wise to buy an 8-speed Chorus derailleur that I can check against my current one?
I’m getting panicky because I’ve got a ride on late November that really requires low gears.
For the weight test, I usually stick a cable in the shifter and stand on the end of it, then go through the gears applying tension. That’s how I’ve diagnosed slipping shifters before, usually 10sp campy escapement? shifters. The crappier Centaur and Veloce ones that only shift down one click at a time.
