I have been reading thru the posts for quite a while and decided I better say hello.
I run a Dax F80 70cc on a 1995 18spd MTB, have about two thousand miles on it.
Currently running on Maxxis HookWorms 26x2.5, slime tubes,
and Mr Tuffy's tire liners(really like this combo in the urban environment),
12 ga spokes in rear wheel, after the stock 14ga spokes gave out.
Standard V brakes with double pull brake lever,
KMC 1/8x1/2 BMX Drive Chain after the stock stretch o-matic chain wore out.
Under Rack mount Fuel tank, really like the tank behind me, no more gas leak on my pants.
Plastic milk crate mount on rear rack as my trunk.
Max speed 29.6 with a 44 tooth. Although I cruise between 18 and 20 mph (its sweet spot).
All in all i love this little HT and the tweaks I keep finding.
I've had my chain jump a time or two, ran out of gas a few miles from home,
lost a front brake pad and did not notice till I needed them and had to stop
fred flintstone style, no crash thou.
My best advice is to wear a helmet, carry some tools and if you ride further than your willing to pedal,
and check those nuts and bolts regularly.