It was July 2023, and I was getting the Vespa car ready for Gould's Microcar Event. Tragedy struck... something broke inside the transmission.

It turns out that the pinion gear that delivers transmission output to the ring gear on the differential lost two and a half teeth.

The in-focus part with the yellow-oily coating is the site of the break. Hard to tell, but the part behind the nut is jagged because of fracture. By comparison to a healthy set of teeth, you can, however, tell. See next picture...

I rode an old scoot ('62 Series 2 Lambretta) over to Microcars. When I told people about the break, they were completely unsurprised. And they were right. An e-motor (first professor Tannenholtz's 185-lb forklift motor, then my 66-lb shunt-wound motor) has an awful lot of torque compared to the two-cylinder, two-stroke 15-hp motor from the original.

I will learn after all of this that the pinion gear is an Achilles' heel of the Vespa car. N. Courtonne, the French connection for parts, has "20 to 30" transmissions with that exact fail. He wants a lot of money plus shipping) for a complete, healthy unit. I might consider it -- what a time saver, compared to building an alternative system. We'll see. The good news is this: Unlike the original forklift motor which was capable, as I have seen, of making a corkscrew out of a half-shaft, my modern e-motors have controllers with programmable caps on accelration. There's my safety.

And so the Vespa car goes into storage for the year to await decisions, and a little time to dig in.

Next chapter: New powertrain. Part XII