Tentative future powered BMX idea

[JTSpeedDemon]

Ok, so I'm tried of being exhausted every time I go up a hill or try to go fast on flat ground. I want to stick a motor of some sort on my Schwinn Dart BMX bicycle(picture attached). I would prefer to have a little four stroke gas engine on there, but electric is also fine. I've never done any modifications to any of my bikes, so I really am not sure where to start. I would think that for an electric motor, I could mount it in the triangle area of the frame and have some batteries on top of that part of the frame. I'm wondering what would be best, to make it a sort of auxiliary to the pedals, or to make it the main power source. Also I want to make sure what I want to do isn't illegal in Texas, because I don't want my bike to be confiscated by a police officer or anything. Still working on my go kart, so this will be WAAY in the future, but I want to know how possible this idea is.

Edited:
Ah! Found out that in Texas, an 'electric bicycle' cannot attain a speed greater than 20 miles per hour and it cannot exceed 100 pounds. That sounds pretty nice actually!

Edited again:
Can be powered by a motor alone or with human power! Might just cut the pedals off, but who knows? Still very open to ideas!

Edited AGAIN:
Might also put the electric motor driving the front wheel?

 

[itsid]

I'd go electric and for sure "reversible"!
So no frame modifications or anything that cannot be undone.

Since that's a small and light bike, you might have a good chance of following Tom Stanton's
example on youtube

it's a tiny RC motor (No.. they are NOT the best choice.. but the smallest decent in your case)
and a rather expensive controller (VESC.. Benjamin Vedder's ESC)
designed with skateboards in mind they are a MUCH better choice than ordinary RC controllers for personal transport..

Anyways such set is rather small in footprint and thus doesn't add too much weight but
quite a convenient way of powering a lightweight bicycle.

small four strokes are much heavier (noisier) and don't necessarily more powerfull.
the ONLY benefit is the better range really.
A similarly tiny two stroke (same'ish range as a four stroke)
would be lighter and more powerfull usually..
soo IF gasoline.. go two instead of four strokes (even louder though)

There have been nice Bike-engines in the past (MAW comes to mind.. but that's a german thing and they're quite rare and expensive)
Some mount directly to the left side of the wheel (as said MAW) (axle nut and a clamp on the frame is all)
looking cool and getting you going quick and easy.
Others mount to the kickstand plate (if your bike has any that is)
and drive the rear with a friction roller (like the Garelli Mosquito engine)
that too is easy to mount and remove (in case) and likely fits even a small frame BMX

I wouldn't even think about chinese crap engines for bicycles nor adding a weedwhacker..
.. but that's personal preference more than anything

'sid

 

[JTSpeedDemon]

I have found on Harbor Freight Tools a few electric motorshttps://www.harborfreight.com/engines-generators/electric-motors.htmlthat I think might work. I think 'compressor duty' means it's designed to spin at a constant rate rather than low speed high speed and whatnot like I would need, which is too bad, because a 3 HP electric motor almost sounds too good to be true! However, the 1/2 HP general purpose one and the 1 HP agricultural farm duty motor sound like they would work a lot better instead of an RC motor. I'm probably going to use a brushed motor just so I don't have to spend money and time with an expensive and probably finicky controller.

 

[itsid]

you will ALWAYS need a controller!
(brushed or brushless doesn't matter at all!)

Those motors are likely BS for a task like yours
(hf website doesn't like me.. so I can't check properly)
but I assume heavy duty (and by that I mean HEAVY in weight as well)
low power AC motors
(a horse is 735W)

a 1kW can be had smaller (my1020 1000W @48V) DC brushed for ~100 and it's matching controller for 20'ish doll hairs.

known to work, (check the forum for my1020)

'sid

 

[JTSpeedDemon]

BS?

 

[pulsar2121]

I have found on Harbor Freight Tools a few electric motorshttps://www.harborfreight.com/engines-generators/electric-motors.htmlthat I think might work.

Those are AC motors. They have to run off of a power grid with a chord. These will not work for battery-powered applications.

Your best option would be to get an electric hub motor kit off of eBay like this one. https://www.ebay.com/itm/36V-750W-20-Front-Tire-Electric-Bicycle-e-Bike-Conversion-Kit-Cycling-Hub/142505890334?epid=2146819308&hash=item212e03521e:g:cwsAAOSwRbtaA0Dd:rk:2f:0

The matching battery pack is sold separately. https://www.ebay.com/itm/142458027561?ViewItem=&item=142458027561

 

[itsid]

BS?

cow dung

since yeah I expected AC...

Those are AC motors. They have to run off of a power grid with a chord. These will not work for battery-powered applications.

Your best option would be to get an electric hub motor kit off of eBay like this one. https://www.ebay.com/itm/36V-750W-20-Front-Tire-Electric-Bicycle-e-Bike-Conversion-Kit-Cycling-Hub/142505890334?epid=2146819308&hash=item212e03521e:g:cwsAAOSwRbtaA0Dd:rk:2f:0

The matching battery pack is sold separately. https://www.ebay.com/itm/142458027561?ViewItem=&item=142458027561

That is actually a good idea! a hub motor of sorts (I prefere rear ones since a pushing rear feels "more natural" on a bicycle than a pulling front;
but they're certainly easier to mount (less chain and such )

IIRC there are also full packs around,
a disc wheel essentially containing a small'ish batpack and the controller, you only have one throttle wire to control the thing coming out..
very slick..

Personally I like the tiny friction roller setups:

(this one's the Add-E sports kit for example)

A tiny fricition roller motor on the left coupled with it's controller (the black box it's fixed to)
All mounts to the bottom bracket with the part in the center

The battery connectors are hidden in the bottle holder and the battery -you guessed it- is inside the bottle (together with an on off switch)

This set is EU-legal with the pedal speed sensor,
thus no extra throttle..

Once mounted only few can tell it's in fact an e-powered bike.

That is very close to what people did with RC motors and the above emntioned VESC controller..
In fact that IS an RC motor right there and I'd bet the controller isn't too far from a VESC by means of code at least...

So yeah... I like it..
And this spring a VESC will be ordered...
and then something similar will be approached
(maybe for MY kickboard, maybe for a Bonanzabike, maybe for my BMX.. maybe for all of them.. we'll see)

'sid

 

[JTSpeedDemon]

Dang, those are some slick setups! At first with the roller design, I thought, 'Well, that would probably have a similar effect to scrub brakes and wear out my tires'. But after reading about it, I doubt it would do that, and even then, the benefits outweigh it. Also, "cannot attain a speed of more than 20 miles per hour without the application of human power", since the Add-E kit only works while you're pedaling, that's perfectly legal! The electric wheel design also sounds good, but I also need to keep in mind that I need to finish my go kart project first. Feel free to keep posting ideas, and thank you!