MotoGP Bans 200-Year-Old Suspension Concept

After much whining from manufacturers who are not Ducati, it seems MotoGP will ban front variable-ride-height devices for 2023. Such devices increase acceleration/braking ability by lowering center-of-mass height (this is why drag bikes are built as low as they are). The decision is a reaction to the predictable objections—it’s too expensive (which may mean “We can’t get our system working as well as the other teams have”) and it’s dangerous (rules require it to be rider-operated, but the riders already have other pressing matters to attend to).

At the very dawn of mechanically powered vehicles, the English engineer George Stephenson had a related idea, and he made it work more than 200 years ago. Because they lacked springs to absorb shocks, early locomotives were breaking both their own structures and their rails, but including such metal springs would have to await the availability of better, more crack-resistant materials. Stephenson’s alternative was to support his locos by boiler pressure, acting on pistons in close-fitting cylinders. The system seems to have worked fairly well, as it continued into the early 1820s. As the engine raised steam before a run, boiler pressure would rise, and so would the locomotive.

Now let’s take a look at the Wikipedia entry on hydropneumatic suspension. A quote: “During World War II Paul Magès…secretly develops the concept of an oil and air suspension to combine a new level of softness…and self-leveling.”

Sounds a lot like variable ride height to me! And designed 78 years ago without computers, crowdfunding, or dynamic finite element analysis. Magès’ employer, French automaker Citroën, adopted his system for its DS automobiles in 1955. Height-adjustable and self-leveling suspension systems have been offered by numerous other automakers.

If you’d like to read about Stephenson’s idea, see page 36 of Anthony Burton’s 2017 book, The Locomotive Pioneers.