Woot! Friction drive by the Cannonball method. Just like the folk who saw the first powered flight at Kitty Hawk I can tell my grandchildren that I was there (in a manner of speaking) when the Cannonball Friction Drive was invented
Thanks! They are not complicated to make. If used with the locking collar mounting system they are an easy and very adjustable bolt on. Both of these were for the narrower hub width, 127mm? I think. I generally make them wider than the actual hubs width to allow fine tuning of the drive lines with shims/washers. They could also be made adjustable by making the hub "U" bracket moveable. A nice addition would be a set of adjusters like used on the horizontal drop out fixie bikes to allow easy adjustments for the drive chain/belt and precise alignment. The hub walks a bit when tightening requiring a few redos to get it where you want it. Fortunately adjustments are only required if you move the hub for some reason. They stay put otherwise.I think you have an awesome design in your hub bracket. getting those in standard widths with specific offsets wold be awesome.
If it turns out that they do loosen then try thicker spokes to see how that goes. I use old spokes for all sorts of things from book marks (nothing better) to hangers for painting bike parts. I find that making that J bend requires a fair amount of force. If there were fewer of them it would increase the force on each one, but with 18 to share the driving maybe it won't be a problem. Time will tell.CB2, I like your 1/4 turn via twisted belt method. That's some real down on the farm engineering!
In many conversations with curtis regarding an inline crank engine, I've considered many options. Today, I'm thinking the lower drive unit, from a small outboard motor with a blown power head, might work well, especially for a friction drive.
...those spokes across the hub, from flange to flange, IMO, is not going to work. The J bends in the spoke will pull straight and you will be left with floppy wire ginsu knives flailing about your tire and possibly sending shrapnel towards the underside of the test pilot!
But it probably won't get that far... soon as the spoke pieces lose tension, you'll begin to lose motivation.
Good luck
rc
Thank you for this really informative thread. Worth a look for anyone interested in a centrally rack mounted four stroke friction drive. It does look like this could be combined with the S.A. IGH spoke drive. Wouldn't that be sweet!