Are you the kind of person who likes to come up with combinations that most people would never think of? If so, then you might appreciate this build from a guy named Kelvin. As he tells the story, he had a Yamaha RD350 sitting around, and then he obtained a frame from a 1963 Lambretta scooter. Synapses started firing in a particular way, and so he decided to see if he could do something amazing with that old Lammy shell. Thus, the Yambretta was born.
Kelvin considers himself just a regular guy who likes to work on bikes, just so we’re clear. He’s the kind of guy who learned to love wrenching at his dad’s side, as a kid—and continued that love on into adulthood and working on his own projects. He doesn’t consider himself an engineer by profession—just a shed guy by passion, really.
Still, you wouldn’t know it by looking at what he’s done here. Watch the video, and you’ll see that it all looks extremely nice and tidily put together. Sure, it’s tightly packaged—but there’s a crispness to this build that you don’t always see in every custom, particularly from someone who’s just doing it in their spare time, and not as a professional builder.
How long did it take? All told, Kelvin says it took about a year to complete. The process involved a whole lot of trial and error and, as you’d expect, some creative problem solving using non-standard parts. There’s a Volvo water pump involved, though Kelvin didn’t offer further specifics. There’s also a fuel pump from a Yamaha R1. A Lambretta wiring loom is involved, but bits of wiring from the Yamaha are also in the mix. The tidy little radiator is neatly tucked away up front, which you can see if you open the glove box.
From making the Yamaha gauges fit up front, to putting everything together, to hand-crafting the exhaust, Kelvin did most of the work himself. One thing he didn’t do on his own was the Kenny Roberts-inspired paint job, for which he hired the services of a professional shop. It is, by the way, a kick-start machine—of course.
What did the whole thing cost? Because Kelvin sold on the parts of the RD350 donor bike that he didn’t need, he estimates that the whole thing only ran him around £5,500 (about $6,246), give or take. Of course, that doesn’t take into account the long hours it took for him to complete the project—but who counts those when it’s something you’re just doing for fun?
It’s an astonishing build, and one that must be pretty amazing to witness in person. If you’re wondering how fast it goes, Kelvin says he’s had it up to about 90 mph. He hasn’t had it on a dyno and doesn’t plan to do that, because he’s not a racer. However, given that the stock Lambrettas only made around six horsepower, the stock 39 horsepower that the RD350 made when new is an absolutely bonkers upgrade—even if the actual number isn’t exact.