7 Speed Rear Derailleur for Brompton Bicycle P/T Line

By using with 10s cogs can support max 7 speed

Due to Brompton frame design, the best result will be 5 speed

Support up to 23T

From our experience, 5 speed with 11-13-15-17-21 (9s cogs) with best performance

or

6 speed with 11-13-15-17-19-21 (9s cogs)