Originally Posted by Seabass_First

Thanks this is really helpful...

1. The stem mount is a rivendale quill stem shifter IRD Stem Quill Shifter Mount

2. Your mentioning that the nylon washer (see my attached image R4) should to be stationary... thus not transferring the rotational force through to R3-R1 really made the penny drop.... I think what is happening is that the braze-on post (B1) might not be long enough to engage the nylon washer (R4) ... so when i'm twisting the shifter to change gears it is loosening every time!



3. MAYBE my chain is wrong (no its not a single speed) its a 5/6 speed exactly this: Robot Check

4. I will get the friction shifter working and then re-asses the chain jump. thanks all!