Now Florian Schlumpf is saying his 2 speed planetary crank will work with a fixed gear

with the 110 BCD chainring option and a 34t chainring , when kicked into its overdrive 1.6X that 34t acts like it is a 54t..

no flipping involved , OK it is Swiss, so not cheap , and the installation requires chamfering the BB shell edge

to engage the conic grip washers that resist the torque in the overdrive range, and it's not light ,,


just a mechanic and I like the reduction gear version I fit on my folding bike.. there a 50t chainring acts like a 20t chainring when
kicked into the low reduction gear [there I get to use my AW3 hub twice in high and low range, for 6 ratios over a wide range]

the other fixed gear 2 speed drivetrain He makes is a Unicycle Hub , so a 24" wheel for highway riding acts like it's 36" in diameter ..

happy to help you spend more than you wished ..