This is a 1994 Sachs New Success branded as IRCOS. It is a tidy, competent item. But perhaps rather out of date.

IRCOS did not acquire the lucky bag of old Sachs (or Sachs-Huret or even Huret) factories until 1999. The logo on this derailleur was trademarked in 1999.

So I have, spuriously, guessed the launch date of this derailleur as being 1999. You may note that it appears to have been manufactured in 1995 and had been sitting on a shelf somewhere for 4 years. This makes it likely that it is an 8-speed.

• Derailleur brands: IRCOS
• Country: France
• Date of introduction: 1999?
• Date of this example: 1995? - it is marked 'W5' on the inner pulley cage plate
• Model no.: RN500? - a guess based on the Sachs number
• Weight: 228g
• Maximum cog: 32 teeth - stamped on the cage
• Total capacity: 28 teeth - stamped on the cage
• Pulley centre to centre: 50mm
• Index compatibility: 8-speed
• Chain width: 3/32”
• Logic: top normal
• B pivot: sprung
• P pivot: sprung
• Materials: aluminium with titanium pulley bolts

Ref. 2018