Thread: Electrathon - A Different Kind of "Hotrod"

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Yes, Ted, Firebird77 is correct. We are using some bicycle components for jobs they were not designed or intended to do.

When riding a bicycle, the rider leans into any turn he makes. The amount of lean is according to the speed and degree of the turn, but the result is that the pressure on the spokes is in a straight line from hub to rim. When turning our Electrathon cars, the wheels are held at a stationary angle regardless of our speed and sharpness of the turn. Therefore, the rims and spokes are subjected to extra stress as the wheel is effectively pushed sideways in reference to the hub. The negative camber helps relieve some of that sideways stress on the spokes of the outside front wheel (The outside front wheel takes the most load transfer during a turn).

My years of building and racing these cars has led to some compromises in engineering and design. I once tried 1 degree positive camber with up to 12 degrees of positive caster - that made the car hard to steer in tight corners. I have tried negative camber up to 10 degrees - that chewed the tread off the inside of the tires and made toe-in/toe-out critical. I even tried dual A-frame independent front suspension that altered the camber angle as the car compressed the suspension in a corner, but it was too unreliable. I finally landed on 7 degrees negative camber and 7 degrees positive caster - it is a compromise that seems to work satisfactorily.

After the unsatisfactory results with my dual A-frame suspension, I replaced it with a rigid mounted front axle. It was strong and reliable and easy to maintain and/or repair. The next 13 cars I built all used that same simple front end. My last two cars have independent front suspension using a split tube front axle with a tubular strut rod (radius rod) welded to the axle tube (pic below). So far it has worked well. I still set it up with 7 degrees negative camber and 7 degrees positive caster. The cars settle and deflect very little, so there is minimal camber change. The purpose of the suspension is just to make my 71-year-old bones take less of a beating on a couple of the tracks that are rough.