Made in Switzerland to watch like precision, is the Schlumpf Innovations range of geared bottom brackets. Instead of running multiple chainrings up front with much overlap in gears, a planetary gear system is employed to provide a unique gearing between the the crank arms and the chainring. This means with the Mountain Drive your chainring spins at 1:1 in direct drive and your cranks rotate 2.5 times for every single revolution in low range. Using a 60 tooth up front in direct, drops down to the equivalent of a 24 tooth in low!
Mountain Drive; high 1:1, low 2.5:1
Speed Drive; high 1:1.65, low 1:1
High Speed Drive; high 1:2.5, low 1:1 All drives $525USD/$700AUD
Also available as an upgrade for all Greenspeed trikes at time of purchase, $375USD/$500AUD (GT3 and GT5 $525/$700)
See Schlumpf for more info and instructions.
