Micro drive is a type of bicycle drivetrain, mostly BMX and MTB, that uses smaller than standard-sized sprockets.[1] The smallest rear sprocket that fits on a freehub body is a 10 or 11-tooth, but with the use of a cassette hub, sometimes called a micro drive rear hub, sprockets as small as 8 teeth may be used.[2]
Some examples of micro drive hubs are Shimano Microspline (12-speed, 10-teeth) and SRAM XD/XDR (11/12-speed, 9-teeth).
- ^ "Suntour Components Catalog 1992: MD (Micro Drive Design)" (PDF). The Bicycle Info Project. Retrieved 2011-08-18.
Smallest rings and gears: by reducing the diameter of the chainring bolt circle diameter on the crank arm, SUNTOUR is able to replace the standard 46/ 36/24 (or 48/28/28) with a compact 42/32/20 on the front chainrings.
- ^ "Wheels / Hub Tech Help". Dan's Competition. Retrieved 2011-08-18.
Currently with a cassette hub you can run as small as an 8t cog.