Maximum USA (Oregon) Legal Motor For Minimum Cost

[Onidaren]

EDIT - Summary: Oregon http://www.oregonlaws.org/ors/801.258 does define what is legally considered an electric bike, and sets the limit at 1000W output for the motor system. This requirement is different or non-existent depending on the state. Federal law places a 750W limit on output (regardless of what the motor is rated), which only applies if you are manufacturing ebikes as a business.

After comparing motor kits for performance, features, and cost, I ended up with a choice between a yescomusa kit or a leafbike.com kit. I chose the leaf kit.

original post below:
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Trying to piece together a USA legal electric bike, to the maximum limit of course. I need a hub motor for which the max wattage given by the manufacturer is no more than 750W. For my purposes, the motor must handle 48 volts with a smile ->

alternatively, if you know about a motor that is underrated and can be cranked up to 750w without burning it up, that will work too.

 

[neptronix]

Max wattage is determined by the controller and not the motor, ultimately.

So if you want to go with a 48 volt setup, you need a 15.5 amp controller.
Or with a 36 volt setup, a 21 amp controller.

Pretty much any motor aside from a wimpy 250w geared motor can handle that!

 

[neptronix]

I'll tell you right now though, the first thing you think after a few hours of twisting the throttle on a 750w setup, you'll be thinking about more power. Plan accordingly

 

[e-beach]

Trying to piece together a USA legal electric bike, to the maximum limit of course. I need a hub motor for which the max wattage given by the manufacturer is no more than 750W. For my purposes, the motor must handle 48 volts with a smile -> alternatively, if you know about a motor that is underrated and can be cranked up to 750w without burning it up, that will work too.

Most of us around here who run on yescomusa kits are happy with them. Very dependable so far. Go with the rear motor kit.

Go here and see what they have. http://www.yescomusa.com/search.php?mode=search&page=1

If they are out of stock, check out ebay because they sell there also. If you can not find what you need wait until they restock which happens regularly.

Mind that is is a diy kit so you will need to spread your frame to fit the motor. That is normal. You may need to put a large washer or 5mm spacer on the axle between the rear cluster / cassette and the frame to keep the chain from rubbing. This is normal also for e-bikes. Lots of info on that.

Let us know how it turns out!

 

[Chalo]

Max wattage is determined by the controller and not the motor, ultimately.

So if you want to go with a 48 volt setup, you need a 15.5 amp controller.
Or with a 36 volt setup, a 21 amp controller.

Pretty much any motor aside from a wimpy 250w geared motor can handle that!

The law limits output, not input.

Also, there is usually no stipulation in the law as to whether the limit on output is momentary, continuous, or rated. Those are very different things, just as a Citroen 2CV has a very different "two horsepower" than a 1500W peak power RC motor.

I'd guess that for the purpose of proving legal legitimacy, rated power is the most important. It's also the most arbitrary, and the least likely to correspond to anything practical or measurable. Our friends in the EU and Australia are intimately familiar with the difference between a measured 250W of power and a 250W (or 200W) rated motor. Here in the US of A, we don't have to sweat it much, because nobody cares. The main requirement is that if you are trying to pass as a bicycle, move like a bicycle. If you do that, you are in the clear.

 

[jkbrigman]

Trying to piece together a USA legal electric bike, to the maximum limit of course. I need a hub motor for which the max wattage given by the manufacturer is no more than 750W. For my purposes, the motor must handle 48 volts with a smile ->

alternatively, if you know about a motor that is underrated and can be cranked up to 750w without burning it up, that will work too.

Everyone who has answered you is pretty much correct. But you need to know how to build this bike.

The bike I've built (see my "Phat Bike" thread) is, unfortunately, legal. My motor has "500W" printed on the side of it, I run a controller rated for 25A max and I limit current to that on the CA. If I'm stopped, I can easily show that I meet both the letter and the intent of the law.

The key to what you seek is the CA. It can be programmed to limit the current through the controller to provide legal power. The CA is invented/designed by Justin and sold by ebikes.ca.

I see you are in Bend, Oregon. Grin Tech is right across the border from you in Vancouver, BC. Give them a call, ask them your questions and buy your parts from them. They will give you professional support. I am sure they have dealt with this question before and can offer good guidance. You will be glad you did.

 

[spinningmagnets]

edit: I know you're asking about hub-motors, but I thought this is worthy of consideration:
For 750W as a legal kit, I have thought very seriously about the GNG Gen2 kit. It looks to be fairly trouble-free.

http://endless-sphere.com/forums/viewtopic.php?f=28&t=45740

 

[amberwolf]

Trying to piece together a USA legal electric bike, to the maximum limit of course. I need a hub motor for which the max wattage given by the manufacturer is no more than 750W.

Except for companies selling whole prebuilt ebikes, there is no "USA-legal" wattage, only state and local limitations. If you're doing it yourself, for yourself, it doesnt' apply to you.
http://www.endless-sphere.com/w/index.php/Definitions_(legal)_of_an_Electric_Bicycle

For your state (Oregon), that limit is 1000w, last I checked, but you can look it up in the Oregon online laws.
https://www.oregonlaws.org/ors/814.405
https://www.oregonlaws.org/ors/801.258
http://www.oregon.gov/ODOT/DMV/docs/pocketbikeguide.pdf
The only other motor limitation is essentially that the controller should have a speed limiter to keep it from providing assistance past 20MPH. (you coudl ride faster, but the motor can't help you).


Here in AZ, there is no power limit at all, but a bike with helper motor must be "operated" (ridden/driven) at less than 20MPH (meaning, since it doens't specify if it's just the motor itself or human power is limited to that speed, and when they enforce anything, police generally enforce that to be whether or not the motor is running, unfortunately, so you cant' even pedal one faster than that, technically, unlike where you are).

 

[Onidaren]

Thanks guys! So, here's what I'm hearing:

- I can put a 1kW motor on my bike in oregon, since I am not a manufacturer.
- the federal law for manufacturers technically allows a motor to be bigger than 750W so long as its output never exceeds that.

I'm very happy to hear this. According to my research both at the simulator and elsewhere, a 1kW size motor is exactly what I need to run a bike at peak efficiency at a speed of 20 mph on level ground. A 1kW motor is also torquey enough to handle the steep hills we have around town (bend is located very close to the cascade mountain range). A bigger motor would lose efficiency (rather steeply) at 20 mph on level ground, and a smaller motor can't take on hills very well.

I plan to put this motor on my city bike, a ~1985 trek 400. Unfortunately, the bike itself is at my house in corvallis so I will need to wait until the end of this month before I can bring it over here.

This project is just to get me started. More power is definitely on the drawing board for later, although I will be building a tadpole trike for that.

 

[e-beach]

I plan to put this motor on my city bike, a ~1985 trek 400.

That would be there "lightweight" road bike of that year. Chrome-molly frame.

Have you measured the gap between your dropouts? Most hub motors need about 130mm to fit. Chrome-molly frames can be spread.

If you want to use that bike, I would recommend a rear hub motor, a torque arm for safety, and putting the batteries in the frame triangle of the bike for optimum handling. Too much weight on the rear rack can make a bike unstable.

Also, what kind of handle bars do you have and where are you going to put the throttle?

 

[el_walto]

I think if you look at the ebikes.ca simulator, you will find that "motor power" is usually about %25 Less than Input power.

It looks like the most torque you will get from a hub would be: the BMC_torque (MAC 10T) at 36v, 25amp controller. 900Watts in, up to 695Watts up hills etc motor power. 31km/h on flat.

Look for the MAC 12T with 20amp controller if you must run 48V

http://ebikes.ca/simulator/

 

[Onidaren]

I plan to put this motor on my city bike, a ~1985 trek 400.

That would be there "lightweight" road bike of that year. Chrome-molly frame.

Have you measured the gap between your dropouts? Most hub motors need about 130mm to fit. Chrome-molly frames can be spread.

If you want to use that bike, I would recommend a rear hub motor, a torque arm for safety, and putting the batteries in the frame triangle of the bike for optimum handling. Too much weight on the rear rack can make a bike unstable.

Also, what kind of handle bars do you have and where are you going to put the throttle?

I actually have regular mountain bike style handlebars already on it (lol, on a bike intended for curly bars). So switching out the handlebars with twist grips shouldn't be hard, especially since the shifters aren't mounted on the handles anyway. You are right to be concerned about the spread of the dropouts, and like you said, I would have to measure. At any rate, I plan to eliminate all but one of the rear wheel gears to make room. There still might not be enough room. We shall see.

 

[Drunkskunk]

Thanks guys! So, here's what I'm hearing:
- the federal law for manufacturers technically allows a motor to be bigger than 750W so long as its output never exceeds that.

Thats not correct ,but it's understandably confusing.

The regulation is 15 U.S.C. § 2085, which is under Consumer Product Safety Commission (CPSC) regulations, not the National Highway saftey commision. Under federal regulation, an E-bike is considered a consumer good not a motor vehicle, and the regulation is only there to define what an E-bike is, not regulate what is legal on the road.

Further more the regulation only states the motor must be rated at less than 750watts(1 horse power). Since electric motor's are normaly rated by nominal output, not peak output, your peak output could be 100 horsepower, and still be legal if the rated nominal power was 749watts.

You can read the regulation here: http://codes.lp.findlaw.com/uscode/15/47/2085

 

[Onidaren]

The regulation is 15 U.S.C. § 2085, which is under Consumer Product Safety Commission (CPSC) regulations, not the National Highway saftey commision. Under federal regulation, an E-bike is considered a consumer good not a motor vehicle, and the regulation is only there to define what an E-bike is, not regulate what is legal on the road.

Further more the regulation only states the motor must be rated at less than 750watts(1 horse power). Since electric motor's are normaly rated by nominal output, not peak output, your peak output could be 100 horsepower, and still be legal if the rated nominal power was 749watts.

You can read the regulation here: http://codes.lp.findlaw.com/uscode/15/47/2085

good point. However, Oregon http://www.oregonlaws.org/ors/801.258 does define what is legally considered a bike, and sets the limit at 1000W (nominal). If a motor is rated for 1000w and can handle several times that while lowering the weight and raising efficiency per dollar spent, by all means point it out.

Guys, keep in mind that the money saved by riding this bike will be about $150 per year. If I keep the bike for five years, it will have saved me around $750 in gas (maybe more, if gas prices keep rising like they have been). So that is my max budget, total, for this project. I want the 48V ping battery for $400, so I have $350 to work with for all the other parts.

 

[e-beach]

Guys, keep in mind that the money saved by riding this bike will be about $150 per year. If I keep the bike for five years, it will have saved me around $750 in gas (maybe more, if gas prices keep rising like they have been). So that is my max budget, total, for this project. I want the 48V ping battery for $400, so I have $350 to work with for all the other parts.

Yescomusa for the kit.
http://www.ebikes.ca for your torque arm.

The rest of the budget for a odds and ends like a better fuse then comes with the kit and other odds and ends.

my 2¢

 

[amberwolf]

Even my common 9C/MXUS 2807 "500W" rated hubmotor will handle at least 3KW+ bursts regularly, as I ride around in stop/start traffic. Typically it only needs to handle 300-500W continuous as I cruise on the flats, but if I go up Cave Creek Road at North Mountain, there are places it takes about 1200W to sustain 20MPH, for a minute at a time on certain uphill parts of the south-west-bound part of CCR.
http://www.endless-sphere.com/forums/viewtopic.php?f=2&t=12500&p=552169&hilit=+cave+creek+#p552169
It handles that just fine, too. I'm sure it could handle it for longer, but I dunno exactly how much longer. I thought I had posted up a run I made northeast-bound on CCR, but apparently I never put the data up. But it did fine on that, too. I don't know what the slope is of the road, but there are some parts steep enough I can't pedal up them on a regular pedal bike. 7th Street is a lot steeper, though i haven't tried it yet (it is much less bicycle friendly) except a downhill run way back when I first built CB2, pedal-only.

I was going to check
http://ebikes.ca/simulator
to see what it shows it to do before overheat, but I don't knwo the slope.

 

[Onidaren]

So far, I'm mainly seeing votes for yescomusa, but I want to put in due diligence before I settle on that.

I did some digging, looking for motor kits like the one from yescomusa, for purposes of comparison. Here is what I came up with. I would like your expert opinion on these choices:

yescomusa: http://www.yescomusa.com/Brushless_Electric_Bicycle_Engine-_48v_1000w_Rear_Wheel_Hub_Motor_Kit.html
leafmotors: http://www.leafmotor.com/electric-bike-kit.html
leafbike: http://www.leafbike.com/products/di...w-rear-hub-motor-bike-conversion-kit-613.html
Amazon: (looks the same as yescom... I think) http://www.amazon.com/1000w-Front-E...UTF8&colid=JR9JJK1AEGXY&coliid=I3MRM4HUSUM5S5

P.S. in bend the steepest hill I will likely be challenging is maybe 20 degrees. we have some beasties here

 

[e-beach]

I would like your expert opinion on these choices:

yescomusa: http://www.yescomusa.com/Brushless_Electric_Bicycle_Engine-_48v_1000w_Rear_Wheel_Hub_Motor_Kit.html

Pro: Known by forum members to be a dependable low cost kit. Con: The stock controller can be a bit under-powered for the most demanding hills. The charger is not intended for LiFeP4. It can work, but won't fully charge your LiFePO4 pack but is good for sticking in your backpack if you want to top off somewhere along the way because if it breaks it is no great loss. No 700cc rim

leafmotors: http://www.leafmotor.com/electric-bike-kit.html
leafbike: http://www.leafbike.com/products/di...w-rear-hub-motor-bike-conversion-kit-613.html

Pro: has a 700cc rim probably more suitable for your Trek 400. Has LCD display for speed, mileage, battery gauge. Con: No charger, 1 break lever, no thumb throttle. (are you keeping your drop bars on that bike?)

Amazon: (looks the same as yescom... I think) http://www.amazon.com/1000w-Front-E...UTF8&colid=JR9JJK1AEGXY&coliid=I3MRM4HUSUM5S5

Looks identical to Yescomusa

P.S. in bend the steepest hill I will likely be challenging is maybe 20 degrees. we have some beasties here

You will be very happy to have motor assist when peddling up those hills!

 

[Onidaren]

I will go with the leaf kit for the following reasons:

- it comes in 700c, which is more likely to fit (although I will definitely check this before buying)
- controller has a higher capacity (last thing I want is to melt anything when I need to climb hills!)
- it is ok that there is no charger because I will either choose a Ping battery that comes with a charger, or build a lipoly pack that I already have a charger for.
- it is ok that the throttle is a twist-grip because I have mountain-bike style handlebars already on my bike, and the shifters are mounted on the frame.
- it comes with a computer for keeping tabs on the system, whereas the other kit does not.

Case closed. It will be a while before I actually place the order because I have to figure out the battery side of things. If you have terrible experiences with the leaf kit, or warnings about the details of installing this kit, please share.

 

[e-beach]

I will go with the leaf kit for the following reasons: ........
- controller has a higher capacity .......

How do you know that?

 

[Onidaren]

Actually, I don't know that for sure. Dug around on both leaf sites. One of them said the controller has a 30A capacity, and I am assuming that both leaf sites are selling exactly the same kit. Capacity is not listed on yescomusa. So they could be the same, but I would rather go with the one that has a rating posted for sure. Even if the controllers turn out to be the same for all the kits considered, it would not have changed my choice.

 

[e-beach]

Actually, I don't know that for sure. Dug around on both leaf sites. One of them said the controller has a 30A capacity, and I am assuming that both leaf sites are selling exactly the same kit. Capacity is not listed on yescomusa. So they could be the same, but I would rather go with the one that has a rating posted for sure. Even if the controllers turn out to be the same for all the kits considered, it would not have changed my choice.

Both my yescomusa controllers put out 30-32 amps under heavy load going up a 10% grade hill, but I am only running 36v 800w. You will be running a more powerful system.

 

[chris...]

leafmotors: http://www.leafmotor.com/electric-bike-kit.html
leafbike: http://www.leafbike.com/products/di...w-rear-hub-motor-bike-conversion-kit-613.html

Pro: has a 700cc rim probably more suitable for your Trek 400. Has LCD display for speed, mileage, battery gauge. Con: No charger, 1 break lever, no thumb throttle. (are you keeping your drop bars on that bike?)

I can or can't use a throttle with the leaf 36V/750W controller?

 

[dnmun]

you can buy this one to start with, and use the money left to buy a cheap lifepo4 48V15Ah pack from the sun-thing guy for $425.

http://www.endless-sphere.com/forums/viewtopic.php?f=9&t=48447