To celebrate their move from steel to modern space-age plastic technology Simplex launched a range that perversely included this living fossil. The Prestige Promotion (511) is a single pulley derailleur - for those stick-in-the-muds who still dreaded the extra ‘drag’ caused by a second pulley wheel.

One pulley gave less drag, less weight - but no capacity and, more importantly, a gear change so imprecise as to be worse than useless.

This version has the early ‘thumb-wheel’ adjusters.

• Derailleur brands: Simplex
• Categories: Simplex - the Prestige story
• Themes: Ultra-lightweight - single pulley models, Small wheels on my wagon
• Country: France
• Date of introduction: 1964
• Date of this example: unknown
• Model no.: unknown
• Weight: 158g including hanger plate
• Maximum cog: 22 teeth?
• Total capacity: 8 teeth?
• Pulley centre to centre: not applicable
• Index compatibility: friction
• Chain width: 3/32” and 1/8”?
• Logic: top normal
• B pivot: sprung
• P pivot: none
• Materials: largely plastic, with a steel pulley cage

Ref. 349