FORGOTTEN MOTOCROSS TECH: COMING OR GOING? REAR FORKS

Motocross history is filled with examples of creative ideas that were heralded as ground-breaking, but, because of the rapid rate of change in development, sank into the swamp of forgotten technology. Although some are best left abandoned, others were truly innovative (if not ultimately successful). MXA reveals motocross’ tech trivia. Do you remember this idea? Rear forks.

Harley-Davidson’s first motocross bike was a byproduct of the marriage of Harley, Aermacchi and bowling pin sugar daddy AMF. When AMF asked Harley to enter the booming motocross market, the Italian Aermacchi firm was tapped to supply its 242cc two-stroke engine for the project. The 1975 Harley MX250’s chromoly frame was sourced from Champion Frames with a Hurst/Airheart rear disc brake. Ghost Motorcycles’ hero Sonny DeFeo debuted the MX250 at the 1975 Herman, Nebraska, National. Only 65 of these bikes were ever made. The most memorable aspect of the $1375 Harley MX250 was the combination of Showa front forks and Kayaba shock-style rear forks.What was it like to race a bike with forks on both ends? MXA’s Jody Weisel raced one in 1975 and said, “It wasn’t fast and needed to be short-shifted. For local racers, the Kayaba rear forks [labeled as Red Wings] were surprisingly good—but not at Pro speed. They seemed to bind up in consecutive bumps. I took the rear disc brake off and mounted a Yamaha hub with a drum brake instead. It bolted right on. It was not a very good bike, but it holds a place in motocross history because of the rear suspension.”

Bengt Aberg’s Bultaco.

But don’t think that Harley was standng alone in field with it’s oddball rear fork concept. Bengt Aberg raced a rear-forked Bultaco in the 500 GPs and often claimed that he thought of the idea before Harley.

The Rear-forked Suzuki.

And Suzuki tested in private, but did bring it’s rear forked bike out in public for a couple races in Europe. It had a weird swingarm that had a clamp on it that held the fork’s sliders in a location in front of the rear axle.

 

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