For Take Offs Only?

[jazz256]

Can anyone direct me in handling my dilemma. I need a suggestion for a electric motor that can pull between 250-300lbs(with me on the bike.) I will be using it for take offs and some periodic power boosts(its a hybrid). Amy wattage and amp ideas for this application? I was thinking about a 48V 1000W electric motor...

 

[Dauntless]

I think a little better explanation of the design might help. I'm assuming you mean to have an underpowered gas engine of some size (50-150cc?) and want some help accelerating. In that case I'd think the hub motors might be physically fragile in such a position, so you'd want a an electric motor. . . ? Oh, give SOME idea. . . .

http://www.ebay.com/itm/KIT-ELECTRIC-MID-DRIVE-MOTOR-BRUSHLESS-48V-1000W-QUAD-CAR-E-BIKE/191529528875

 

[jazz256]

sorry about that, here is a better explanation. I build board track racers, and most of my board track racers are geared very low. Because of my low gearing, it puts a lot of stress on the engine's clutch and other drivetrain parts. Currently, I am working on a Briggs and Stratton powered BTR and the gearing is low(2.5:1.) Since my gearing sucks, I need another means of off the line acceleration. That is when the idea of adding an electric motor came into play. Right now, the bike weighs less than 65 pounds in its current state. Fully dressed and with me on it should be between 270 and 300 pounds. My question is, what will be a suitable electric motor and battery combination for my bike? I will be using the motor to take off and occasional bursts of power for hill climbing and such. And just clarify, I need to accelerate 270 to 300 lbs.

 

[Dauntless]

So I'm assuming you're using the Chinagirl moped kit. Yeah, there's something that's getting flogged in use.

Well, it occurs to me that the motor I posted is ready for some heavy lifting, but maybe this is a situation where the venerable 80100 might shine. That's been a popular motor here, but people have been known to overwork it. It's an undersize (And light) motor that people overload. If you're only overloading it a matter of seconds before the gas engine takes over, much like starter motors are, that might be just the role it'll thrive in.

There's quite a bit of information on people using those around here. A lot of opinions, arguing, insistence on things that turns back around on them, etc. But people were indeed talking about something they were using.

http://sxicl21.motors-biz.com/item/32568/RC-outrunner-brushless-motor-C8085-C80100.html

http://skyhobby.company.weiku.com/item/ATN-series-C80100-08-Outrunner-Brushless-electric-motors-for-RC-toys-13210386.html

 

[jazz256]

So, I can use a starter motor for an electric motor!? Dude, that's awesome!

 

[Dauntless]

Actually no, I wasn't saying that. I was making an analogy to the stress a starter motor is under when you use it. You probably won't be happy with it on your bike.

 

[jazz256]

oh, yea, that makes more sense. I'm still debating on getting a 48V 1000W engine, but im not sure what type of batteries I would need. More importantly, how big does the batteries need to be?

 

[Ohbse]

What sort of speed are they geared for currently?

Battery size really depends on how many stops and starts you're planning on doing. There are some very high power density batteries available, so grunt is not an issue but range would be depending on just how much juice you're using per start.

Frankly I think once you experience a proper electric setup you're going to be better off ditching the ICE entirely.

 

[jazz256]

As far as gearing goes, I have no idea. Its a belt primary to a chain secondary.

 

[John in CR]

Accelerating to what speed, and what kind of % grade and length of hills?

 

[jazz256]

John in CR, in between 10-20 mph, and as far as hill grade, it varies greatly where I live. That said, commonly a 40% is about marginal.