Proshift MKS rear mech help

[rwm1962]

Just acquired this rear mech. If I tighten the M5 mounting bolt to the tightness I'd normally use, the mech won't pivot. I have to back the bolt off slightly for it to pivot properly.

Is this normal for these? I'm concerned it drops off while I'm riding although the bolt does not seem to pivot with the mech.

Thanks in advance.

 

[pete_mcc]

Doesn’t look right to me. The stop plate looks incorrectly oriented, usually the Allen bolt stop should be pointing backwards (except in mark 1 derailleur):



here’s a bad shot just taken from my bike:


is the spring in the right way? Looks like someone has incorrectly fitted the spring, then reversed the b-screw So that it’s pointing the wrong way and the Allen bolt is then mid-aligned.

To avoid loosing the mech the old trick was to run a bit of fuse wire through the bolt and the hanger and tie it off against itself

 

[rwm1962]

Thanks for that. Will check & report back later.

 

[pete_mcc]

Just been checking and that looks like a Mark 1 plate on a mark 2 derailleur. Maybe they changed half way through production, maybe someone incorrectly fitted it as a replacement.
Mark 1:

Mark 2:

 

[pete_mcc]

Just for clarity, mark 1 looks like this:

 

[rwm1962]

I think it's assembled correctly & moves as expected.


Plus an image from the net:

 

[pete_mcc]

So that looks like a ‘transitional’ mech, half mark 1 and mark 2! Funky

 

[rwm1962]

Well out of my comfort zone with this. I decided to suffer half rations for a while to add some old cnc bling to one of my bikes.

 

[pete_mcc]

With you 100%. I have one bike covered with it!

 

[rwm1962]

Looking at an exploded view of one of their mechs I can't see anything that would prevent the tightening of the bolt to bind the pivot. But they do state a deep chamfer on the frame can cause it to be snug & to back off the bolt a tad. My frame mount doesn't look particularly deeply chamfered but going to try it on a different frame.