Born to be Mild
A new automatic transmission lets newbies tear up the road without grinding up gears
Engineers have tried and failed for decades to build motorcycles with automatic transmissions. Honda finally gets it right with the new DN-01 “sports cruiser” bike. Conventional automatic transmissions, like those in cars, lag when you hit the throttle and can throw a bike off balance during turns. Honda’s HFT (for Human Friendly Transmission) responds to the throttle instantly by using hydraulic pumps instead of standard gears.
The HFT offers a range of gear ratios similar to a conventional six-speed manual, and it has about the same weight and dimensions. The motorcycle goes on sale in Japan this year, though a price has not been set. Honda hasn’t yet decided if America’s weekend rebels will get their own auto-shifting bike.
Launch the gallery to see how Honda’s truly fluid transmission works.
Honda DN-01 Transmission
Honda DN-01 Transmission (step one)
2. As the disk spins, it depresses a circular set of pistons [B] around the shaft.
3. The pistons eject high-pressure fluid that travels through a chamber [C] and pushes out a second set of pistons [D].
4. Those pistons press a second tilted disk [E], causing it to spin and transmit extra torque (leverage) to the drive shaft.
Honda DN-01 Transmission (step two)
Honda DN-01 Transmission (step three)