This is a homemade motorbike built around a 1900cc car diesel engine. My favourite bit of the video was around 13:05, where the builder mentions that car clutc

This is a homemade motorbike built around a 1900cc car diesel engine. My favourite bit of the video was around 13:05, where the builder mentions that car clutch springs are much stronger than bike clutch springs - cars use a single plate clutch, versus a multi-plate motorbike clutch, so it requires very stiff springs to get enough friction. To overcome this, he tried various arrangements of levers and hydraulics with no luck, so the eventual solution was to cobble together a mechanism where the cable from the clutch lever pulls a chain, which spins the input shaft on a power steering motor, the output shaft of which pushes a metal rod, which pushes on the hydraulic clutch master cylinder, which pumps hydraulic fluid to the clutch cylinder to open the clutch. It's a delightfully heath-robinson-esque setup. Also, the hoses which would have run from the engine cooling loop to the heater core now feed straight into the metal tubes of the handlebars, for toasty warm hands in winter! There's a separate video here covering the gear lever mechanism - motorbikes normally use a sequential gearbox with a foot lever, whereas this gearbox is out of a manual car, and apparently figuring out how to adapt the latter to the former was one of the hardest things to design. The final gearshift design uses a combination of a foot lever and knee paddle to drive the forward/back and left/right motions of a manual gearstick. https://www.youtube.com/watch?v=lC9pCAnBihk https://www.youtube.com/watch?v=lC9pCAnBihk And of course there's a video of the whole thing being ridden here: https://www.youtube.com/watch?v=TeKVedTpo0c https://www.youtube.com/watch?v=TeKVedTpo0c