Originally Posted by
norskagent
Bumping this thread to add a bit of info that I couldn't find via web search. I recently experienced low gear slipping due to the retrofriction screw not being tight enough, of course I didn't have a big screwdriver with me so I walked a few steep hills and managed the rest of the ride. When I got home I tightened the screw and it held low gear fine, just a bit more resistance when pushing the lever forward. Then I looked into replacing the o/g screws with button head 3mm allen screws. I have braze on shifters, they take 20mm long M5 screws. (The length is what I had trouble figuring out online). I found some at the hardware store. Also, unbranded (mavic?) retrofriction shifters have slightly different pull vs simplex branded retrofriction shifters, I had to adjust the limit screws when I switched from one to the other.
As surely noted already in this thread, the resistajce from the Retrofriction levers all comes from the cltch spring. If sny resistance is provided by the pivot anchor screws, it 8s incidental and just results from differing tolerances from the actual design of the shifter.
if the shifter is slipping badly, it could be a worn out inner shifter drum or clutch spring or even over lubrication of the clutch spring that's keeping it from gripping the inner shifter drum.