Browning Automatic Transmission

The Browning Automatic Transmission is a bicycle transmission that is far superior to current designs. The product sports an automatic shifting design in that the bicycle computer will automagically determine what gear to be in based on spoke and hub magnet counts. In addition to that, the shifting mechanism is a radical improvement over the standard derauiller design. For those who like control, the system can be shifted into a fully manual mode.


There is currently a 4-speed version of the bicycle slated for market release to multiple vendors as well as a 12-speed number in the works.


Browning Automatic Bicycles is a company owned in part by the former owners of Browning Automatic Rifles (or just Browning) for short. The company owns several sub-orginizations:
Browning Component
which is responsible for the machine shop as well as the distribution/manufacture of the transmission.
Browning Research
Which is in the business of general R&D with the Automatic Transmission still as their main project

Some info on the bike

The major ideas Browning Research developed include a replacement for the age-old derailleur system used to change gears since the 1800s. The gearset actually changes into an effective spiral allowing the chain to ride up the gearset. It shifts wonderfully under load and is beautiful to watch. The Browning crew have termed the thingie a selector
Basically, the selector works by tripping a one-time cam so that springs pull the guide either left or right. The selector guides a small metal tab that is attached to the gearset either direction, spiralling the gears in that direction. As the tab hits the guide, it pushes the selector back to the middle as it shifts. The 4-speed bike transmission is good for approximately 50,000 shifts before depleting the battery (a simple 9-volt cell).

The bike computer uses hysteresis to keep from dithering from gear to gear; it also has a system whereby you can tell it to change gears in automatic mode and it will remember to change to selected gear under similar conditions if possible.

  • The browning computer uses an 8051-based controller (Phillips is the current manufacturer used)
  • Browning Automatic Rifles made a 10-speed bicycle before the Browning family left the company; that bicycle was used as a testbed for the first gearset designs.
  • The first design of the shifting mechanism had no smarts; in fact it was purely mechanical
  • The bicycle prototypes proved to be a major advantage during Olympic Racing trials; professional bikers shaved seconds off currently held world records.
    The bike was unfortunately banned from the Olympics under a technicality; which is just as well, the US would have won hands down had it been introduced

They have the following patents (all viewable from Delphion)

  • US5073152
  • US5261858
  • US5152720
  • US5356349

Oddly enough, they managed to get away with patenting hysteresis, so don't do it or get sued

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