Shimano-Road - In picture: Derailleur POSITRON ll. To develop safe, reliable and easy-to-operate shifting systems for any cyclist, Shimano announced POSITRON in 1974. This rear derailleur is equipped with an index system
How do I regulate this Shimano Positron so that, when I go to the highest gear, the chain does no slip out? : r/bikewrench
gears - Problems with shifter? - Bicycles Stack Exchange
CYCLE TECH: 06/01/2020 - 07/01/2020
Shimano Positron Derailleur Rear FH Vintage 10 Speed New USA NOS | eBay
Shimano Positron II 5 Speed Stem Shifter Set with Cable