Own and ride a Brompton, which has 16" wheels. It's perhaps marginally less stable than a full-size bike, but I'm willing to believe that it's mostly down to st

Own and ride a Brompton, which has 16" wheels. It's perhaps marginally less stable than a full-size bike, but I'm willing to believe that it's mostly down to steering geometry (smaller wheels limit how far behind the intersection of the steering axis and the ground you can put the contact patch) not gyroscopic effects.