Paul Components Melvin Chain Tensioner. Converts frames for single speed use. Long enough for a Dingle-setup, (2 rings, one cog) 20T max.

• The Melvin uses two pulleys, just like a rear derailleur, which gives it 20 teeth of chain wrap
• Will work with multiple front chain rings while maintaining proper chain tension
• The pulleys are made of extruded and machined aluminum and have sealed bearings for durability
• Pulleys are 2.25mm thick at the tooth which fits inside most narrow 6 through 9 speed chains, and the pulley cage is wide enough to allow 1/8″ single speed chains as well
• Long enough for a Dingle-setup, (2 rings, one cog) 20T max
• Do not use with a coaster brake or fixed gear