Electric bike build

[Mr_hankypanky]

I'm building a trike this year and want to make it electric assist. I have a 48volt motor from a craftsman lawn mower and 4 agm batteries that I salvaged out of a semi. So I'm wondering if anybody has done and seen anything like this or would have suggestions on what watt speed controller. Or any input on it in general. I'm trying to post pics of motor and batteries but can't seem to keep getting error message.

[EGAZ]

You do have a few hurdles ahead of you. Have you looked at the electric bike forums? I would start there first.

endless-sphere.com

visforvoltage.org/

sheldonbrown.com/

There are more......



If the semi batts are as large as I think they are, their weight is a big issue. The other is the brushed motor, it will get hot running at a lower voltage for the 5mph speed. Along with the controller. Then you have to machine a pulley for the trike, or a chain drive for the motor.

It can be done, but it will take some work. Good Luck!

[Molotov]

If you take the pedals off the trike and run it strictly through an electric motor, (which also eliminates your "limp home" option) does that make it fall out of the category of an electric assist bike/trike and become a vehicle which might need BRC DMV licensing?

Excerpt from BRC web page Bold font and comments are my own...

ELECTRIC BICYCLES
Electric bicycles as defined by Nevada state law may operate during the event without any sort of license. That definition is as follows:

“Electric bicycle” means a device upon which a person may ride, having two or three wheels, or every such device generally recognized as a bicycle that has fully operable pedals and is propelled by a small electric engine which produces not more than 1 gross brake horsepower and which produces not more than 750 watts final output, and:

Is designed to travel on not more than three wheels in contact with the ground but is not a tractor; and

Powered solely by such a small electric engine, is capable of a maximum speed of not more than 20 miles per hour on a flat surface while carrying an operator who weighs 170 pounds. (This part is a bit ambiguous-does it still require operable pedals?)

The term does not include a moped.

[maladroit]

Powered solely by such a small electric engine, is capable of a maximum speed of not more than 20 miles per hour on a flat surface while carrying an operator who weighs 170 pounds. (This part is a bit ambiguous-does it still require operable pedals?)

I think they're not taking away the pedal requirement, just saying that the motor alone should only be able to make 20mph on flat ground. Presumably it would be legal to travel faster than 20mph with a combination of human and electric power.

[Zubeneschamali]

Suggestion is to sell those 4 AGM batteries and use the money to buy a front rim electric drive kit for a bike. That kit will bolt up without a feat of engineering and you'll be riding electric assist in half a day.

[lvictory23]

I'm building an electric assist trike as well this year. I am NOT however doing as much DIY as you are. Looking at either scavenging a electric bike hub motor or buying directly from someone like Luna cycles.
I'll ask my partner if he knows anything about how you'd rig what you have on hand up.

[Zubeneschamali]

Electric trike is the way to go. Did a single in 14, a side by side tandem in 15 and 16, this year its coming back + bringing a triple chariot.

[fireheadwhale]

[quote="Molotov"]If you take the pedals off the trike and run it strictly through an electric motor, (which also eliminates your "limp home" option) does that make it fall out of the category of an electric assist bike/trike and become a vehicle which might need BRC DMV licensing?

Excerpt from BRC web page Bold font and comments are my own...

ELECTRIC BICYCLES
Electric bicycles as defined by Nevada state law may operate during the event without any sort of license. That definition is as follows:

“Electric bicycle” means a device upon which a person may ride, having two or three wheels, or every such device generally recognized as a bicycle that has fully operable pedals and is propelled by a small electric engine which produces not more than 1 gross brake horsepower and which produces not more than 750 watts final output, and:




https://swagtron.com/ebike/folding-electric-bike/

So this is not usable in BRC?

[Molotov]

In my opinion, the eBike depicted in the ad would not be permitted as It would fall into the same category as a motorized scooter, because it has no pedals to propel the bike without electric power, and it has a seat. A stand-up only version with no seat would be legal. The lack of pedals combined with the only 4-10 mile range means you will probably be pushing it back to camp several times. Those tiny tires increase the probability of a face plant when you hit a dust drift or rut. I do like the little disc brakes, though.

[rmc50]

I am not sure how you would be adapting an electric motor to your trike. But it sounds like it could end up being a vast overkill. I suppose if you have the motor and the batteries, and the skill to do the adaption it would be economical.

I added electric assist to a trike and a pedicab. In both cases I used front wheel kits that I bought off the internet.

For the trike I used a 24 volt 250 watt geared motor. Three 18 AH batteries provided plenty of power.

For the pedicab I used a 24 volt 500 watt direct drive hub. The pedicab is heavy, and there is usually two of us, so I used three 35 amp-hour batteries. With these, and providing at least some pedaling, I could run all day.

What really helped out was making it easy to recharge the batteries. The 24 volt charger was only a couple of amps so it could take many hours to recharge the bike batteries. I had a little pig-tail wire with a connector hanging out so that I could just hook up the charger whenever the bike was back in camp. To run the charger I had two golf cart batteries running an inverter, and then a 45 watt solar panel to recharge the golf cart batteries. This set up worked very well for me.

R. Mc.