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Pedal Assist

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Old 02-04-16, 10:33 AM
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Roytoy
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Pedal Assist

Is it better for the motor to start out at the lowest level of pedal assist and then dial it up after you're moving, or is it better to start at say, 3 (of 5 levels) so that it gets the revolutions going faster right away? I'm thinking about heat from inrush current possibly causing damage over time.
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Old 02-04-16, 10:53 AM
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I may be mistaken, but I don't think it especially matters under normal circumstances.

What you want to avoid (as much as is feasible) is dumping a lot of power into the motor when there's a lot of resistance preventing it from spinning. For instance, dumping maximum power into a motor that's struggling to pull you up a hill will generate a lot of heat and can trigger an automatic shut off or outright motor failure.
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Old 02-04-16, 12:48 PM
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I don't think it really matters if it's just for a second or two, prolonged max power going up a long steep hill, now that can be a problem... IMO
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Old 02-04-16, 02:11 PM
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My theory is that the transistors are either full on or full off. You get the same instantaneous current when the transistor is on. Speed is determined by how fast the controller pulses that current. As you go faster, the duration of the off times gets smaller as the wheel spins faster, and you use more current. Still, at low speed, you draw the same current.

So I don't think it matters either, unless you help the bike start by adding some decent leg power. That will be easier on the gears in a geared hub motor and easier on the motor in a mid drive. I don't think it makes a difference in directdrive.
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Old 02-04-16, 03:21 PM
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Cool. Sounds like I have been driving it right. I turn on the assist, and just start pedaling.
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Old 02-06-16, 12:27 PM
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The motor quality and the battery management system are important. A really good one (like Bionx) will make sure nothing is damaged by reducing power as needed and then restore it when things cool down enough.
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Old 02-06-16, 12:53 PM
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Originally Posted by profstack View Post
The motor quality and the battery management system are important. A really good one (like Bionx) will make sure nothing is damaged by reducing power as needed and then restore it when things cool down enough.
Exactly, BionX even has a "mountain" mode setting where it alters the assist level to keep from overheating and not end up with no assist at all for big/long hills...
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Old 02-06-16, 03:49 PM
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Originally Posted by profstack View Post
The motor quality and the battery management system are important. A really good one (like Bionx) will make sure nothing is damaged by reducing power as needed and then restore it when things cool down enough.
I feel like I got a decent starter bike, but I'm hoping to move up to this "state-of-the-art" stuff eventually. I've read ok reviews on the Bafang and 8fun, (mine's a 500w 8fun) but my bike all geared up with everything was only $1699.00, so I'm sure there is some super amazing stuff that I know nothing about yet.
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Old 02-06-16, 04:08 PM
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Originally Posted by Roytoy View Post
I feel like I got a decent starter bike, but I'm hoping to move up to this "state-of-the-art" stuff eventually. I've read ok reviews on the Bafang and 8fun, (mine's a 500w 8fun) but my bike all geared up with everything was only $1699.00, so I'm sure there is some super amazing stuff that I know nothing about yet.
This site has a lot of people who put their own systems together. I'm one of (I think) few who buys the ebike at retail with service provided from a LEBS. Your system sounds more than adequate for your needs.

Be careful to not get complacent when riding, or you might take a spill, as I found out a few weeks ago. No injuries to me, but the bike got dirty and the front disk got out of alignment, which was fixed at home.
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Old 02-09-16, 01:07 PM
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Originally Posted by profstack View Post
This site has a lot of people who put their own systems together. I'm one of (I think) few who buys the ebike at retail with service provided from a LEBS. Your system sounds more than adequate for your needs.

Be careful to not get complacent when riding, or you might take a spill, as I found out a few weeks ago. No injuries to me, but the bike got dirty and the front disk got out of alignment, which was fixed at home.
I have been concerned about complacency. I try to stay focused, which is hard when I'm having so much fun. Good advice, and thanks for the input.
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