neptronix wrote:I can imagine that rocks and road debris would be flying at a pretty damn high speed and you'll go through so many tires, something like a new rear tire in the hundreds of miles.
Well, I'll say I've been getting the idea that friction drive is sort of counterintuitive: All these things you THINK are supposed to be a problem don't seem to be. A kid around here built a friction drive BMX with a weedeater and the knobby tire has held up just fine. He built a crude but effective version of the release arm as these people depict, seems almost as though his SHOULDN'T work but it does. It does occur to me that if the contact point for the friction drive is more than 60 degrees after the friction patch on the ground, the junk should have cleared the tire if it's not stuck in the tread.
However, if you don't want to follow Mr. Magnets advice on the moped tires, there are kevlar/aramid tires that are durable. If you ever get to working with composites you'll see kevlar just plain doesn't let you cut it. I've never seen it get unraveled. I don't know ANYTHING about what these hookworm tires people talk about are made of. But your more mainstream cheap bike tire will mean that less than double the speed brings less than half the life.
Meanwhile I read about the RC plane crowd occasionally bending the shaft on their 80100 engine planes, I couldn't imagine that it could survive a few hundred miles as a friction drive, but that and smaller are apparently working out for people.
Ever considered just driving the wheel via chain?
Well, the friction drive is tantalizingly simple, what an accomplishment he's going after. You're asking him to walk away from a challenge.
I just got a cheap little RC motor and controller to run at 12v to build my first throttle grip for an RC controller and in general to see how it holds up as a friction drive. The idea is it would make a $60-80 modification to make anyone's bike electric, at least for getting around local. Make it chain drive and you run up the price some. Then the guy that lost his job, lost his car, went to work at the convenience store on his bike would have a cheap way to get a little farther from home. (I know a few of those; as do we all at the moment, right?) Wish I could see def215's, but everything is the same shade in the pic; he seems to have beat me to it.
rearengine wrote: To Dauntless ... Thanks
Me? You're the one sharing in here. How is the housing itself holding up?