John, I have repaired and taken apart countless Simplex derailleurs. They are easy to work on. When cleaned up and relubed, they still work great. There is a plate with a tange on it that butts up against the hanger on the dropout. That plate looks like it might unscrew but it really just gets pried off with a narrow screw driver. The + that you mentioned means more tension (if I'm remembering correctly). Try pulling everything apart, cleaning and relubing. Then try playing with the different spring holes. If you still don't get enough tension, the spring might just be worn out. Check with an older local bike shop that has a "derailleur parts box". They are usually cardboard boxes that are at least 20 years old and found under most shop work benches. Be careful if they let you pull it out and root through it. They usually fall apart when slid across the floor. In there you will probably find an old Simplex Prestige or Criterium. I have used springs from these as replacements on my "junked" LJ's. I am running one now on my PX 10. I have not had any problems and the tension seems fine. If you are not sure about what the proper tension should be, grab an older drop parallelogram that works fine and check the tension by feel. Good Luck!
Don Andersen Columbia, MD
PS. Don't throw any old der. parts away.
>Hi,
>
>I'm currently trying to get a Simplex super LJ rear mech to work.
>
>The LJ as I can see it has three springs.
>one for the jocky arm tension
>one for the parallelogram tension
>and one in the piviot pin assembly which controls the 'b' tension
>
>It's the latter which is causing the problem.
>some previous owner has fiddled with this and it now doesn't have much
>tension or maybe it doesn't need that much. There's a little plate
>with two holes with a + - sign on it guess so you can vary the ammount of
>'b' tension.
>
>This little plate pops off and you can see the conical spring beneath.
>the LJ mounts to the frame hanger by being screwed in from behind.
>
>So maybe its broken or maybe it isn't.
>
>ANY advice would be welcome.
>
>
>Cheers,
>
>
>John
>
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