It doesn't. There are fast e-bikes out there. Recently I was out running on a country side road. I was passed by some guy testing an e-bike, going astonishingly fast. Knowing the exact distances along that road (it's exactly a mile long, and I know where the half mile split is), I clocked how fast it took him to get to from the half mile mark to the one mile point (crossroads) where he stopped and turned around. He was doing between 50-60km/h, taking some 30 seconds to go 800 meters.
Didn't catch the make of the e-bike.
I heard that there are supposed to be speed limits in these things, but if so, it seems people are able to circumvent them.
Some people will live with hardware throttled to 25 km/h that can inherently do double, some will find workarounds to tap into its true potential.
[Edit: that aforementioned rider wasn't pedaling, by the way.]
https://www.fietsenwinkel.nl/fietsen/-/elektrische_fietsen/s...
They're quick of the mark too, and with the limiter disabled they'll be a lot quicker than the stock 45 km/h.
However, it’s very easy to buy a wheel with a built-in motor that is more than that:
http://www.hi-powercycles.com/hpc-5000w-hub-motor-complete-k...
Get two of those and you’ve got a 10KW electric motorcycle that could probably hit 70+MPH easily.
There are also kits in the 2KW-4KW range that are much cheaper (~$500). If you ban these, you’d have to ban all electric motors, and “winding wire around spinning apparatus”...it’d be very untenable, and there are already laws in place governing max speed and power. We have the same thing for emissions in some states, and enforcement is slim to none. Basically, you have to just count on people using it responsible, just like with motorcycles / electric skateboards / electric wheelchairs / snowmobiles / dirt bikes / gopeds / mini bikes / pit bikes / go karts / pocket bikes / powered paragliders / RC cars etc etc.
How will EBikes be significantly different? All of these have legal uses and a small percentage of owners using them outside of their legally allowed scope.
I don’t think it’s a big enough problem to warrant more regulation. Also, more regulation != more enforcement. Will police carry portable dynos or ammeters and measure the output of your ebike? More likely is that idiots keeping up with traffic at 50MPH will get ticketed by police who notice. It’d actually be great IMO if you COULD have a light electric motorcycle that could go ~35-40, plate it like a motorcycle, and be allowed to ride on normal bike lanes and trails as long as you keep it under 15MPH or whatever the trail speed limit is.
Just like with “drones”, these have existed for decades, but now they’re a “problem” because any punter with a few hundred bucks can buy one ready to do stupid things with at a local shop or off Amazon.