When someone rides a bike down a hill they go faster than they go up. It's not unusual for an ordinary bicycle rider to go 40 to 50 mph on a downhill and that's without any special motor helping them. I have a hill nearby which is posted at 40 mph and I've coasted down it at times when the motor was broken and I'd get up to at least 40 mph without any power at all.
The 20 or 30 mph speed limit only applies to motor created flat land speed.
18 hp on a bicycle would translate to about 100+ hp equivalent on a motorcycle because of the power-to-weight ratio. It's the sudden rush of power that gets people in over their heads. It's already completely illegal to have that much power just about anywhere, so I guess since you are already illegal that you can't get in much more trouble. However, I dislike the fact that it's so seductive to so many... it's hard to push the idea of an "Electric Bicycle Road Racer" with all it's sophisticated design when someone else just sticks a big motor on a bike and calls it a monster.
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Think of things from the larger perspective... if you really want to get into "Big Power" then wouldn't it make more sense to get into an electric motorcycle?
My concept (still evolving) is to keep the power down and then focus on improving the efficiency by reducing the wind resistance, improving the powerband shape (things like Inductance motors and flat torque curves) and making sure that the handling can perform when the rider needs proper handling.
This should really be discussed on the "Politics and History" thread as I created it specifically for this topic.
"Big Power" just sort of dwarfs the whole concept of an ebike. Ebikes are supposed to be very limited in power... that's why they are ebikes and not emotorcycles.
The "bottom line" is that ebikes with that much power destroy what I'm trying to create... (so you see why I'm against it)
Your success in creating "Big Power" is a problem in the bigger picture.