Hi All,

Greeting from Australia. I’ve recently acquired a nice Eddy Merckx Professional which I have just reassembled.

im having an isssue with the rear derailleur - when I shift up from the small rear cog it always springs back, normally to the second smallest cog. Everything seems in order with the reassembly but I cannot figure this out.

Its an early 1980s version, I have attached a photo from the rear.

Any ideas please?

Thanks, Chris



Rear photo

The friction adjustment of the shift lever holds the derailleur position against the force of the spring.

Yeah, sometimes too much lube in the right shifter. Or a worn out washer. Or just not tight enough.
On one shifter that liked to loosen, I cleaned the male & female thread thoroughly and used loctite to keep it from rotating.

Sounds like insufficient tension of the shift lever wingnut. Campy shifter levers were really primitive and did a terrible job of holding adjustment so that there was enough friction to keep the RD from slipping or having too much friction to shift lightly. Much better use for their shift levers was as a keychain ornament. Common and acceptable fix was to replace the campy shifter levers with spring/ratchet simplex or suntour shifter levers that actually work. Short of that, try tightening them down more but expect them to feel stiff and randomly loose tension adjustment.

As with many things clear loctite can be your friend on this.

what era of shift levers do you have?
all metallic or plastic internals?

the assembly scheme and where to place ANY lubricant is different.

the lever friction should keep the selected gear.

Thanks everyone - I pulled it apart, cleaned it and lubricated the tread. Working perfectly now!

Really appreciate all the feedback!

Thanks again

Thanks, cleaned it and lubricated it. It’s now working perfectly!

Make sure all the parts are there, especially the little washer behind the screw. Make sure it’s tight and as mentioned a little loc tite wouldn’t hurt.

Yeah BITD I tried to "upgrade" to the Simplex retrofriction levers that you claim "actually work", LOL. Less than a month later the spring broke on the right hand shifter when I was 35 hilly miles from home.
There is a lot to be said for simplicity and redundacy. Even if they didn't work that great, Campy would get you home with a lttle twist of the D-ring. Properly installed (ah, there's the problem 99% of the time IME) they worked pretty well.

Perhaps the outer anti-rotation washer hasn't quite settled onto the lever boss with the two engagement flats?
It needs to be engaged over the flats, or the washer can rotate, and the screw tightening force won't be able to compress the friction sandwich of the lever between non-rotating washers.

Thanks Everyone,
Cleaned and lubricated the treads and all working perfectly now.
I really appreciate all the quick advice!
Cheers, Chris

Picture of the Merckx would go down well plse