1971 Aluminum Frame Big-Clutch Engine Husqvarna

A little quiet around here lately so thought a bit of HVA history would be of interest. Here are some pics of Husqvarna’s 1971 aluminum frame project and eventual demise.


The following are abbreviated excerpts from Husqvarna Success by Gunnar Lindstrom.

Part 1

The engine used was the soon to be released Big-Clutch 250cc for 1972. The frame was constructed with aluminum tubing bonded with aircraft adhesive to cast aluminum bosses. This was of interest to Husqvarna as it could lead to a simple, light, and inexpensive frame to enter into production.

Part 2

At the 1971 Swiss Grand Prix, Thorleif Hansen’s frame broke on a downhill jump. Heikki Mikkola was told to sit out the second moto in concern that his frame would also break. The break was attributed to a poor casting, but Husqvarna thought the negative publicity was too embarrassing and ended the aluminum frame project.

Great story. Too bad the failure didn't happen in testing. They might have tried another design. "What if."
I hope Hansen wasn't hurt? And I bet Heikki didn't take lightly to have to miss that race, but I understand.