Three Wheels Plus Two Motors = ?
For more years than I can remember I’ve longed for an electric vehicle. As an electronics engineer they hold a certain aesthetic appeal which has drawn me to them. While building an electric motorbike is my long term dream, it is a huge financial investment which I could never attempt in a half-arsed manner. Go big or go home.
Since that’s off the cards for the foreseeable future I set my sights on something smaller. I considered all manner of vehicles; push bikes, scooters, skateboards, etc. In the end I stumbled across two things which lead me to decide on a form factor. This post (http://build-its.blogspot.com/2013/03/electric-tricycle.html) and the obscure, fun, and insane looking sport of drift triking.
A small detour down into the world of drift trikes, almost all of which are custom built, and a little spreadsheet used to calculate gear ratios, power consumption, top speed etc and I arrived at this:
Well that’s the plan so far anyway. Currently missing are the seat, optional extras such as brakes, lights, etc and more importantly I have no idea where or how I’m going to attach batteries and motor controllers. Just in case you missed it, the two orange things, are ~2kW electric brushless RC motors. They will be coupled to the wheels by a #25 chain and sprocket (8 teeth to 64 teeth). Running off a 10Ahr 30V battery I should be able to get to ~50kmph and get to 30kmph within 2 seconds. Of course there’s plenty of power there so a trade off has to be reached between acceleration and top speed, I’m leaning towards acceleration under the presumption that any more than 50k on this thing is going to be … unpleasant.
A number of details are still bugging me (the above mentioned aside) such as the exact headset angle and top tube length. As drawn I worry it may be bit of a stretch to the handle bars, but that will be hard to know until I have the bits available to set out and do a test fit.
Now that I’ve given an overview of what I’m hoping to achieve I think it’s time to call it a night. At some stage I plan on making a post where I discuss the nitty gritty of my decisions and the trade offs I’ve made. That post will be dedicated to the people like me who don’t shy away from a little basic math & physics.