Discussion on the E-Bike forums all too often seems to be about bragging rights. Too much is never enough! The goal seems to be a moped with occasional pedaling. I'm curious about the opposite of a bicycle with just enough occasional or gentle assist. As always there's a disclaimer here that I don't care if it's a bit illegal!
I'm wondering what's the lightest possible way of getting 200-250w with a reasonable range. The kind of controller strategy I'd want is something like this.
Pedelec/cruise,
- Low. Full power to 10mph then nothing.
- Medium. Full power to 10mph then decreasing power with speed, bottoming out at 50w or so at 20mph but unlimited speed after that.
- High. Full power, unlimited speed.
Throttle only,
- Variable power, not variable max speed.
Using Low to get you slowly up medium to severe hills and to get off the line quickly, with pedal effort for everything else, it might be possible to cut the battery needs a lot and still get a reasonable range. 5Ahr might even be enough. I'd also want a really efficient freewheel and drive train so the bike was no harder to pedal than a conventional bike.
So then the question is how light can you get this whole setup. Is Motor+Battery+controller < 5Kg possible? How about 3Kg? Now we're talking about an assist hybrid or touring bicycle that is really no different to ride motor off than one without the assist but takes the pain out of the hills and gives you a little more speed and speed average. And/or a range of 50 miles or so.
Take the same thinking and put it in a faired, streamliner recumbent. Hill climbing speed wouldn't be much different, although a lot easier on the thighs than a plain 'bent but a sustained 30 mph on the flat should be easy.
So overall a focus on just enough performance and as light and efficient as possible. How much of this could be done now?
I'm wondering what's the lightest possible way of getting 200-250w with a reasonable range. The kind of controller strategy I'd want is something like this.
Pedelec/cruise,
- Low. Full power to 10mph then nothing.
- Medium. Full power to 10mph then decreasing power with speed, bottoming out at 50w or so at 20mph but unlimited speed after that.
- High. Full power, unlimited speed.
Throttle only,
- Variable power, not variable max speed.
Using Low to get you slowly up medium to severe hills and to get off the line quickly, with pedal effort for everything else, it might be possible to cut the battery needs a lot and still get a reasonable range. 5Ahr might even be enough. I'd also want a really efficient freewheel and drive train so the bike was no harder to pedal than a conventional bike.
So then the question is how light can you get this whole setup. Is Motor+Battery+controller < 5Kg possible? How about 3Kg? Now we're talking about an assist hybrid or touring bicycle that is really no different to ride motor off than one without the assist but takes the pain out of the hills and gives you a little more speed and speed average. And/or a range of 50 miles or so.
Take the same thinking and put it in a faired, streamliner recumbent. Hill climbing speed wouldn't be much different, although a lot easier on the thighs than a plain 'bent but a sustained 30 mph on the flat should be easy.
So overall a focus on just enough performance and as light and efficient as possible. How much of this could be done now?
