This Falcon 20 is one of a legion of forgotten derailleurs produced in Taiwan in the last decades of the 20th century. Many are out on the road, working hard to this day. They are easy to find and very hard to find out about.

This particular model, also sometimes branded as a Falcon Dynamax 20, is a fairly faithful reproduction of a low-ish end Shimano model. Its one, non-Shimano, feature is the interesting, but rather clumsy, mechanism that adjusts tension at the b-pivot bolt.

• Derailleur brands: Falcon
• Country: Taiwan
• Date of introduction: 1990?
• Date of this example: unknown
• Model no.: unknown (inner parallelogram plate stamped '3I0 Taiwan’)
• Weight: 263g
• Maximum cog: 28 teeth?
• Total capacity: 30 teeth?
• Pulley centre to centre: 56mm
• Index compatibility: 6 speed?
• Chain width: 3/32”
• Logic: top normal
• B pivot: sprung
• P pivot: sprung
• Materials: steel pulley cage and parallelogram plates, aluminium B-knuckle and plastic P-knuckle