4 ms·
> 750W power limit on all their ebikes That's quite the limit. That's one hell of a limit. Most people aren't planning on going 40-60 MPH in a bycicle. From w
by gravypod 10y ago
> 750W power limit on all their ebikes
That's quite the limit. That's one hell of a limit. Most people aren't planning on going 40-60 MPH in a bycicle.
From wikipedia: "When considering human-powered equipment, a healthy human can produce about 1.2 hp briefly (see orders of magnitude) and sustain about 0.1 hp indefinitely"
A 1HP DC motor (or if you want to get crazy with speed control and all that jaz you could do a 3 phase system with a PDM from a torq-controlling pedel or something) is more then enough! Hell we don't even need that. Let's think a .5 HP 1 phase 60Hz motor. This clocks in ~800 watts at continuoious max current but we'd probably not be doing constant drive on this. But let's say that we can pay a little more and find a perfect 750W motor for this at .5 HP. That's a lot of torque given that most people can only sustain .1 HP. This motor (which is crazily oversized by the way) is rated for .5HP @ 3450RPM. 3450RPM at the chain is different to the gear ratio at the wheel. The lowest gear ratio on a bike is about 1.9:1 so our motor would be putting out quite a bit of thrust and even at the reduced torque you'll be halling ass.
Now this is a super oversized motor but anything that can take 750W continuious input is some serious shit. That's one hell of a motor and to complain that that is too small? Get a harley and tinker with that man.
[0] - http://www.ebay.com/itm/MARATHON-1-2HP-AC-MOTOR-M400095-208VAC-1PHASE-60HZ-3450RPM-CONTINUOUS-DUTY-/351072233034?hash=item51bd89264a:g:S4AAAOxyyFhTdOMs http://www.ebay.com/itm/MARATHON-1-2HP-AC-MOTOR-M400095-208V...
- loeg 10y agoWell, ebike parts do add significant weight to a bike (maybe ~50 lbs). So it is reasonable to have slightly greater than human power to compensate for the additional weight.
- dreamcompiler 10y agoExactly. The first 200-300 watts of an e-bike just serves to compensate for the additional weight, especially if it's a hub motor. It's a gain of nothing, at a cost upwards of $1000.
- flubert 10y agohttps://www.google.com/search?q=hp+to+watts https://www.google.com/search?q=hp+to+watts
- HNaTTY 10y agoOne megahertz is more than enough. That's enough power to compare like three-thousand integer values per second, which is way more than a human can do. We've got these guys out there, and they've got 3 gigahertz and more! And they're not even using them! They're playing Candy Crush for gosh sakes! These people are wasting energy and these super-powered CPUs are a potential fire hazard and we need better regulation enforcement now! If we restricted high-powered CPUs to people with a license and a documented need, the world would be a safer place for me. ...In all seriousness, 1hp is not serious shit. And motorcycles are significantly faster and more dangerous.
- gravypod 10y agoThe difference is that adding MHz will only make the CPU noisy, not make it unridable. 1HP @ 3k RPM at the shaft is insane.