The front wheel needs to be bigger I think. Not for comfort but for safety. This makes me want to design one. Roughly, bigger front wheel, hard (no pneumatic)

The front wheel needs to be bigger I think. Not for comfort but for safety. This makes me want to design one. Roughly, bigger front wheel, hard (no pneumatic) tyres. Suspension on the rear wheel; a low unsprung weight would make this effective. It reduces the use case to short distances, not commute rides. But that's ok if it's small enough folded to be taken on a train/bus/taxi.