I guess it depends on the person. I can give you my reasoning.
I just moved across the country from Ontario to Alberta. I sold my motorcycle (DRZ400SM) before making the move. I wanted to do some bicycling exercise on flats, but I also wanted the option to replace my dual sport motorcycle and go anywhere with it (in terms of terrain), and maybe even commute with it, so I decided to go high power. It was also fortuitous because I never looked at the topography of the area before moving, or deciding to build this bike, and I now live in a quite hilly area. One of the hills is ~4km long and ranges from 6.5% to 10% grade. In order to get my fatass (~200lbs) and my bike up that hill at the max allowable speed of 32kph it takes ~1500W to accelerate to that speed over 5 seconds, going up the hill, and ~1250W to sustain it (made an excel spreadsheet to calculate). And that is just a road based hill, there are lots of other steeper hills, some unpaved, some only with stairs connecting walking paths because they are very steep, that I want to attempt.
On the non-hill areas, I would like to be able to feel like I am riding a motorcycle, even if I am only going 32kph (that's approximately how fast we would go when I went to motorcycle safety school, and it was envigorating! lol). In unregulated areas, or private areas, I'd like to go even faster if possible.
I should not be legally required to own 2 electric bicycles if I want to ride in all these environments. The government should trust me enough to keep to the speed limit in public areas, just like they do with motorcycles and cars. In Canada there are essentially 4 types of 2 wheeled vehicles under federal regulations, bicycles, power-assisted bicycles, limited-speed motorcycle (aka mopeds/scooters), and motorcycles. Bicycles are effectively unregulated. PABs are limited to 500W/32kph. Mopeds are limited to 70kph. Motorcycles are unlimited.
I would be willing to effectively have to do everything that a LSM (which all 500W+ ebikes legally are) has to do, that is max bike speed of 70kph, have proper headlights, indicator lights, brake lights, reflectors, horn, mirrors, always wear a helmet(do anyways), get insurance, maybe even licensing (I have a motorcycle license, so this doesn't matter to me personally). As long as it meant I could ride the bike anywhere, on the roads, in parks, offroad trails, private property, etc... Of course following the 32kph rule for public areas, and just generally being safe and not a douche, like slowing down to a maximum of 15kph when passing people, giving them at least 1m of space if possible. I could go and register my bike as an a LSM right now, I have all the parts to turn it into an LSM sitting on a shelf in my office, but then I would lose the ability to ride through the park, which I am not willing to do, so I have to hide in public, I have to fake my motor power with a cheap sticker.
On a more technical side, the idea of motor power being an item of regulation is, frankly, stupid. The nominal/continuous power rating (the "sticker" rating) of a motor is only the amount of power that motor uses at peak efficiency. That's it. It has nothing to do with speed, acceleration, or torque. It has absolutely no motive metric, or safety metric. The only logical power rating for a motor is peak and how long that peak power can be sustained for, and that is only so the user knows what levels to set the controller at so they don't fry their motor. Even your legal 250W/500W BLDC hub motor could run at more than 250W/500W, even much much higher if it was cooled properly.
Suffice it to say, I think I need more than 500W, more than 1000W, to use this bike comfortably the way I want to use it.
marvak said:
Can someone explain to me please, what nominal or continious watt rating of motor means?
If I have somekind of pedal assist torque sensor, and turn pedals at 400w for 3 minutes, can 250w rated direct drive motor, continiously supply 100% of my effort? Buenvie
For the most part, the ratings given are for peak efficiency. So when a motor says "500W nominal", it means that at its peak efficiency the motor uses 500W of power. An example I can give is a high power hub motor, the QS205 50H V3, it has a nominal power rating of 3000W. That means when it is at its peak efficiency, of 93%, it is using 3000W. Not really all that helpful of a metric, if you ask me.
