In answer to the original question of the OP (not the second follow up question):

Have you ever tried to pedal a commercial moped or scooter equipped with pedals gas or electric? They absolutely suck when it comes to actually using the pedals, they are only there to make them legal in states that require usable pedals for them to be street legal. I want a motor assisted (electric or gas or other power source) bike to make full use of the human power plant as well and allow me to make a meaningful and useful contribution by continuing to pedal even when the motor is running and allow me to run without the motor under pedal power alone with only the additional weight of the non-running motor being the only determinate to pedal only operation. Like others on this forum I like to (in order of importance to me):

~ Climb hills better, faster, and easier then I can do under pedal power alone.
~ Carry, haul, and tow more cargo weight at higher speeds and up bigger hills then I could normally do under human power alone.
~ Go faster over longer distances then I can under pedal power alone.
~ Be able to ride the 10+ miles home with minimal pedaling at 3-4 a.m. in the morning when I'm beat tired after pulling a 14+ hour double back to back work shift fighting a 20+ mile an hour head wind in the form of a blizzard with 2" of blowing drifting snow (studded snow tires rock) on the roads and still not have to resort to using a car.

I own and operate a fleet of multiple motor assisted bikes that I built myself, some from kits, some not from kits, some I built from the ground up starting with welding my own frame. Some are human/electric hybrids, some are human/gas hybrids, and one is a three way human/electric/gas hybrid. The important thing to me is that ALL of them have a fully functional human pedal drive that is set-up so that both:

~ The bike can be effectively and efficiently driven under human power alone within its limitations (the 1/4-ton cargo hauler is a little slow under human only power especially when loaded to its full hauling capacity and the dedicated towing bike is also a little slow especially when towing a heavy trailer load).
~ Continuing to pedal while using the motor as well produces a noticeable improvement in both acceleration performance and top end speed (have to get the gearing right on both the motor and pedal drive to accomplish that and properly tune them to each other) and/or increased range for the electrics or decreased fuel consumption for the gas assisted bikes. This provides the incentive for the rider to continue to pedal even when the motor is being used because he can feel the difference and feel the extra performance and speed by adding his own power to the equation and not just relying on the motor alone. The additional benefit of longer range and better mileage although not an immediate gratification also helps.

Those are important features in my mind that are severely lacking in almost every commercially produced scooter or moped out there and I consider them almost essential to ensure the rider is "in the game" and it is my opinion that keeping the rider in the game makes for a better safer driver and reduces mechanical abuse of the motor drive system such as trying to climb a hill without downshifting as necessary and "lugging the engine" on a gas engine or badly overheating an electric motor by dragging it down to too low of an RPM and trying to compensate by just dumping more and more watts into it.


In answer to the OP's follow up questions:

As to the level of assistance, the lowest assistance bike I have is one that has a custom built "hill helper only" set-up using the lowest wattage and voltage cheap front hub motor I could find that is instead built into a custom rack inside the right rear pannier bag that is hooked to the rear wheel of the bike via. a second chain on the big 34 tooth #1 position "granny gear" on the rear sprocket spool providing a 2.125 gear down ratio which will drive the bike up a hill using the limited wattage available to provide high torque at low hill climbing speed. Because the motor is geared down so much on the flat I can pedal faster then the motor can go so there is absolutely no reason to use the motor on anything but going up a hill and if it isn't a very steep hill I can still pedal up the hill faster then the motor can drive the bike so it only gets used as an assist for climbing steep hills otherwise it actually slows me down when it is engaged. It runs off a small capacity (for minimal weight) battery pack that is good for a little more then 40 minutes of assist time. I built it to be set-up that way specifically and very deliberately. I have help for climbing the steep hills but nothing more then that because the motor is geared to low and goes too slow on the flat so their is no point in using it except to help when climbing a big hill. I consider this the purest form of a motor motor assisted bicycle and is more true to the pedal bicycle then even a PAS system that only helps out when you are pedaling only because a PAS system will help you go faster on the flat and its use isn't limited to hills only.

My most powerful bikes all put out the maximum legal power by the laws of my state for them to not have to be registered as motorcycles - that being 2-horsepower (about 1,500 watts).

For the electrics some like the bike with the hill helper only motor have a very limited range - only about 6-1/2 miles for that one since the max speed under motor power alone is only about 10-mph and you only have 40 minutes of battery power but if you only use it for steep hills that is 6-1/2 miles of steep hills which can take you a long way if you are not using the motor on the rest of the route. Currently my longest range electric can go about 20-miles under motor power alone, double that if you are constantly pedaling and keep the motor at lower power levels in its peak efficiency range.

For the gas bikes its not a matter of range but rather of fuel efficiency. All of them running unloaded without hauling or pulling heavy cargo loads will get at least 80 miles per gallon even if you aren't pedaling. My most efficient one consistently gets over 150 miles per gallon and I've almost broken the 200 miles per gallon threshold on several rides with it where I was strongly pedaling the entire way on long flat ground runs. The 1/4-ton heavy hauler bike (the three way hybrid power bike) will get at least 50 miles per gallon even with a full load if I'm not running in extremely hilly country and I'm doing my part. The lowest mileage I've ever gotten was with the dedicated towing bike where I had about 200+ pounds of weight on it itself as cargo and for traction on the two rear driven wheels while pulling a trailer with about a ton and a half of cargo on it, I still got 30+ miles to the gallon even when running in very low gears to tow that much weight over fairly hilly terrain.