Based on out of South Windsor, Connecticut, Drouin made belt driven superchargers for a variety of bikes, like the Sportster Super Glide and the CB750 – though they had most of their success with the Norton Commando. Here’s a 850 that’s been given a variety of custom features, but the star of the show is obviously the Drouin, which was an aftermarket item but could be ordered through Norton dealerships.
The Drouin unit weighed about 15 pounds and claimed to boost torque up to 78%. This scanned article from the December 1976 issue of Street Chopper shows installation of the kit on a Commando 850 and they measured a 1/4 mile time of 11.2 seconds @ 124.1 mph with a claimed top speed over 150.
This example (VIN: 315731) has 13,669 miles and has several modifications of note: “competition fairing”, full instrumentation package, Corbin gun fighter seat, twin oil coolers with custom oil lines, slide throttle fuel injection, and more. The seller claims that this engine now puts down 100 horsepower. Flaws include old tires, some small dimples and discoloring on the rear fender, and some pitting on the wheels. In this year’s Riding into History Motorcycle Concours, this bike won first runner up in the all Norton class.
Find this supercharged Commando for sale in Fernandina Beach, Florida with bidding up to $6,332 and the reserve not yet met