Having had many of the different drive systems, I can tell you NO motoredbike should be 'Jackrabbit' started from a stop. ALWAYS pedal assist your take offs, it's easier on the engine, the bike, and related components. I like 'em all, but I believe friction to be outdated technology, though some great advances have come to the friction set ups (heck, I still run the p'diddley outta mine...), I am sold on the newer advances in belt technologies.
I've had a few discussions on the GEBE set up, and having a few miles in the saddle I can speak from experience here. The belt may look flimsy. It is not- provided it is aligned properly. I personally know riders with 4,000+ miles
on the original belt, it is a Kevlar belt that is tough as nails. Furthermore it is a 'toothed' belt with teeth on the sheave as well, so unlike my Whizzer, there hass NO slippage in the rain thus far.
Many have commented on the (so called) "plastic" belt sheave- it is not plastic as such, but rather a composite developed for use in the aerospace industry; again, tough as nails in my experience. The one thing debated between friction and belt (or chain) drive is the stress on the spokes. Again I re-iterate the above. NO motoredbike should be started from a dead stop without pedal assist. If one wants to do that go buy a real motorcycle, or a moped. And ANY motored bike should use a MINIMUM of .105 spokes.
Again I'm not denying the friction drive, or any other drivetrain for that matter, and I really dig DE's 'rain roller' concept, it's just that I think it's an outdated mode of powering a bike and for the cost, the GEBE is a better system IMHO. I'm not kn ocking any other companies, or their products, I own and ride many different drivetrains on my M/B's.
Again, I speak from experience- I'm not just blowin' smoke here; this ain't my first ride at the rodeo...
Rif