Looking at the Millet with it's direct drive in the rear wheel made me wonder?
Engines of this type are notoriously hard to get a slow tick over. even 500 rpm will be optimistic
So if we assume a standard 26" wheel, my rusty maths make that 38 MPH. !!!!!
It's hard to imagine what the gyroscopic effect of that rotating mass had on the steering as it accelerated ?
It also appears to have a rudimentary form of trailing link suspension at the front with a leaf spring.
When these engines where used in aircraft to get them to slow down the engine was " Bliped " turned of and on,
later models where made to run on alternate cylinders
Oh to be able to go back and just listen to the discussions of those days.
Brian.