Originally Posted by
Kontact
You have described how the spring clutch releases, but not where the friction comes from. And it comes from the screw tension put on the perfectly round barrel that is shown as item 5 in the patent drawings or far left barrel in assembly 3534 in the parts break down.
Without tension on that barrel, the lever would not hold any position against derailleur cable tension. The spring clutch grabs that barrel securely, and when you push forward the spring twists the barrel with it. When you pull back on the clutch, the spring opens and moves without the barrel. The barrel only moves forward, the spring only releases rearward. The spring release has no real friction, which is what we like about 'retrofriction', but the spring grabs and drives the barrel when pushed forward, and that's the friction that counters the derailleur.
You seem to be suggesting that the clutch spring, that does such a wonderful job gliding backwards, is then tearing the barrel up by being forced to drag forwards despite its tension. How long do you think a system that relies on the grip of a hardened steel spring is going to last if you are overwhelming that grip to get the lever to move? That's crazy.
Forward movement happens with the barrel slides around mounting post 3533 against the friction provided by inner washer 3532 and outer washer 3528. And the tension screw, through washers 3527 and 3526, provides that friction on the inner washers to the barrel.
The play you are noting is the interface between the barrel and the lever/spring clutch assemblies.
Have you actually opened up one of these shifters and looked at the spring and barrel separated? If you look at one that had been used for a long time, you will see how the spring will eventually wear grooves on the barrel from gripping it and providing the resistance friction. THe internal barrel does not move with the lever as it is keyed to the base of the lever mounting boss. The internal barrel takes all of the friction duties along with the spring. The mou ting screw and the face washers under it, just retains the lever and internal barrel on the shifter boss with minimal pressure. If you somehow add pressureanf friction to the shifter assembly, you are not utilizing the Retrofriction feature as it was designed which is zero friction when pulling the lever back and friction when pushing it forwards to resist the derailleur springs. This makes the action as light and as smooth as possible as you only have friction in one direction, which is resisting the derailleur spring. If you add friction through the mounting screws and washer somehow. You are uselessly making the action of the lever heavier in both directions. The springs and barrel do wear out eventually after years of use, just like any other shifter. It can be fixed by replacing the internal barrel and/or spring, which I had successfully done on a couple of my Retrofriction shifter sets. You can also just switch springs and internal barrels around with other Retrofriction sets and it could work, if the wear grooves on the barrel does not match up exactly with the spring coil pattern.
Did you ever wonder why Simplex just provided the shufters with the most rudimentary mounting screws with such shallow slots and nut a wing nut or a D ring screw? It's because they do not exoect it to be tightened periodically for maintsining friction for the shifters as with other friction shifters. It gets screwed on tight enough to keep the levers on the boss once and that's it. You would not jave to touch it till you have to take off the shift levers for any sort of servicing.....
If you insist on using your Retrofrictions like any othe friction levers, go ahead. It's too bad as you are not tsking advantage of the original design of the levers..... I give up trying to explain this over and over again...
if you want to see how it should work, I have ten bikes I can show you with it installed and working properly.....