I had to start a separate thread about this item I saw in Hal's thread. It's a really simple and apparently smooth working multi-speed gearbox meant for the cranks, but it seems ideal for a DIY transmission for our non-hub drives. http://www.nosmokemtb.it/UK_phaser.html
Other than nailing down the shifting mechanism to make it something trouble free, it's brilliantly simple and uses cheap off the shelf parts. Add in that it's more efficient than a derailleur with easily a 4:1 gearing range, and it just doesn't get any better. Well maybe it does, since imagine how small it would be using #25 chain, which is better at higher speeds anyway, and I think stronger than regular bike chain, but then you'd have to fabricate the 2 cassettes.
I came to the realization today that geared hub motors can never stand up to high powered demands I have, since their critical parts have no sufficient thermal pathway for heat conduction out of the motor. Add in their limited surface area and the issue worsens. I have 2 mountains to cross and one of them will require a minimum of 1000W (probably more like 1500-1800W) continuous for an hour at relatively slow speed, so a non-hub drive is now mandatory for me. Yes it's heavy and yes it will take up a lot of space, but my 12kg hubbie is coming out of the wheel, and I'm attaching at worst a jury rigged version of the Phaser, even if I have to stop and manually change gears for my coast to coast ride. I look forward to HAL9000's attempt at one, and I'll share my own more feeble attempts, both successes and failures.
Maybe as a group we can come up with a simple and bullet proof DIY shifter for this thing. Maybe the inventor's shifting rig is simple, but I can't tell so, I'd like to discuss that further.