Dave Wilson and the Improved Safety Bicycle Part 2: Outriggers

Recall from the previous post that the late Prof. David Gordon Wilson reintroduced recumbent bicycles to the public as safer bicycle in the mid-1970s. Interest in recumbent bicycles had languished and a design competition he sponsored in the late 1960s resulted in him building and riding recumbents to work. Ultimately Wilson was featured in a Mobil Oil Ad and he became the face of the recumbent bicycle.

https://www.youtube.com/watch?v=lYbfz4vCczg

Wilson felt that the lower, feet-forward riding position of a recumbent bike would reduce injuries from falls and front end crashes. Wilson advocated under-seat steering to remove the handlebars from the rider's path in the event that the rider was pitched forward during abrupt stops.

He was very cognizant of the fact that the bicycle's simplicity and consequent low cost contributed greatly to its popularity a transportation alternative for many people.

One feature Wilson did not pursue was improving stability on slippery surfaces by adding an additional wheel. Possibility this was because an additional wheel (or two) complicates the construction of the bicycle significantly.

There are at least three conditions that would necessitate needing a statically stable layout instead of a bicycle. The rider has trouble balancing a bicycle. The rider climbs very steep hills that are difficult to balance on. The rider rides on slippery roads and trails.

Now, even though Wilson's recumbent experiments dealt with bicycles, his first edition of Bicycling Science did include a sketch of an enclosed bicycle with outriggers.  

Notice that the outrigger position front-to-back brackets where the cg location is typically located. This insures maximum roll-over resistance for a given track of the outrigger wheels.

Now, I am sure that the intent was that the outriggers would only be used for starting and stopping. But could they be designed so the bicycle could be ridden under transportation conditions with them extended, producing a four-wheel diamond-layout vehicle for improved safety?

I propose to use the outriggers a bit differently than usual. The outriggers would share a common pivot on the frame. They would always stay in contact with the ground. There would be a spring located between them that kept both of them in contact with the ground no matter the flatness of the surface. There would be a spring stop between them that insured they moved together once the spring was compressed.

The outriggers could operate either of two ways. If the common pivot was locked to the frame, the vehicle would act like a fixed four-wheeler. For example when the vehicle was parked or riding on a slippery surface. If the pivot was unlocked it could free lean like a bicycle.

An alternative to free leaning is to have a lever that would control the angle of the frame to the outriggers, allowing leaning to be adjusted by the motion of that lever. Leaning would not be automatic like free leaning but would require the rider to control the amount of lean consciously.

So, if the outriggers are to be in ground contact all the time, why not make the vehicle a quad by providing four regular wheels? In the US and Canada, four-wheel pedaled vehicles are not classified as bicycles or tricycles. The designation is particularly important if the vehicle is electrified and operates on bike paths and bike lanes.

The bike with outriggers I am proposing should be legally considered as a bicycle because the outriggers are like training wheels on a regular bicycle and are ancillary to the basic design.

Hephaestus