Positron help please.

[HerrOtto]

I am working on my first Positron system, and I hope my last. I believe this is the first generation of Positron. I have found very little online regarding adjusting these systems, but I did find some instructions, which I have followed to a "T"(probably at least 25 times by now). My problem is, I can get it to work up the gears or down the gears but not both. The best I can get it is, it will work going from 5 to 1 but coming back down, from 1 to 5, it gets stuck at 2 and won't drop down to 3 , w/o me adjusting the only adjusting screw, and now I have messed up 5 to 1. I have made sure that the derailleur is straight and at initial set up, the derailleur is indexed at 3rd gear, along with the shifter being in 3rd, as per the instructions. I know these systems are not well liked and can be switched out to a friction or newer indexed system, but I feel I should be able to dial this one in. Any help is appreciated. Thank you

 

[HerrOtto]

Problem solved

 

[GTs58]

Problem solved

Just curious, what was the problem? And I assume it was the Positron II.

 

[HerrOtto]

The rear derailleur is marked Positron FH, no FFS. The problem was the spring for the derailleur cage was frozen, not rusty. but I assume old grease. Once I got the spring moving, everything fell into place and works as it should. This really wasn't a true Positron problem, as it could have happened on any derailleur. I know most guys think the Positron system wasn't necessary, but I look at it as, a step in the right direction towards index shifting.