I'm currently designing the "electric bike of my dream" (please do not laugh! it's for fun, nothing serious), and I came up after some though with a tricycle, where 2 rear wheels are supporting the battery and cargo weight, and a suspended front part for the rider.
The simplified kinematic of the bike is the following:
The link between the front part (in blue and red) and the rear part (in orange and green) would be made by two rotations: R1 for suspension, R2 to be able to move the front part sideways when making a turn. The rear part is supposed to stay vertical (well, more or less perpendicular to the road anyway).
My question is about the suspension part, and its influence on the "rideability" of the bike. I was thinking of putting two suspensions (SL and SR) to provide some positive "feedback" on R2 when making a turn, and to make the front part stay vertical when parked. On paper this looks nice, but I was thinking that this may be a problem when:
- the road has potholes, or when crossing some curb sideways: the front part (and the rider) will experience some disturbing force sideways;
- when making a turn the behavior will not be exactly the one of a normal bike as you need a stronger push to tilt the front part.
The feedback force and behavior would depend on the choice of d and h as seen on the diagram (h can be made negative if needed).
Another (probably simpler) solution is to only have one suspension in place of SL and SR, w/o any "feedback" couple.
What would be better in your opinion? Does a small feedback for R2 would render the bike not rideable?
As a bonus some "artist" views to get the whole picture (on the rear view you see only one suspension):