diy ebike

>>1212105
>What is wrong with this?
Be the first to find out.

guy on thingiverse printed some pully-based ebike using a brushless motor

>>1212105
This is a pretty common project, if you do the math you should get a reasonable idea of how the system performs before committing dollars to build it.

The brush-less hub motors tend to be more popular because they are easy to use. Mounting an RC brush-less motor securely to the frame isn't trivial.

>>1212105
well first of all how much torque can one of these put out at 10000rpm? you must be a fat fuck if you can't be bothered pedalling a bike so it will have its work cut out i guess.
second you have made a motorbike now, typically it will fall under motor vehicle legislation and you have a shit ton of hoops to jump through. ebikes get past this by making sure the motor only helps while you are actually pedalling rather than pushing for you. if you stop pedalling it cuts out.
how many batteries will you need, how much weight will they add and how long will they run for. never used a quadcopter but what is the run time about 10 seconds? sure its running 4 motors but the load is about 1/100 of pushing you and the bike up a hill.

>motor too hot.
you are getting fucking way ahead of yourself. put down the binoculars and concentrate on the problems right in front of you first. burn that bridge when you come to it.
>not enough low end torque
motors develop their maximum torque under stall conditions. if it doesn't have torque low down i have some bad fucking news for you...

>>1212159
>you must be a fat fuck if you can't be bothered pedalling a bike so it will have its work cut out i guess.

I like the hypocrisy of assuming everyone with an ebike must be a lardass, while not batting an eye at the fact that probably 95%+ of the population commutes in a car.

I'd be willing to bed that the average ebike owner is significantly less overweight than the general population.

>second you have made a motorbike now, typically it will fall under motor vehicle legislation and you have a shit ton of hoops to jump through. ebikes get past this by making sure the motor only helps while you are actually pedalling rather than pushing for you. if you stop pedalling it cuts out.

None of this is correct, at least as a blanket statement. In my state (California), they recently re-defined what an "ebike" is. As is the usual with California, they managed to take one step forward and then screw it up by overcomplicating it all to shit. Under 20mph, you're fine no matter what, but for some reason, they decided to make a distinction between pedal-assist and throttle-operated bikes that max out at 20mph.

There's no fucking difference in how they're regulated or where they can operate, there are just a separate definitions for them, because California.

20-28mph and it's legally an ebike if it's pedal assist only. I mean, they don't put a limit on how much assist it can provide, though. So you can basically just set the thing to 99% assist and have the pedals operate with no real effort, effectively turning them into a weird pedal throttle. But an actual throttle is not okay, because, again, California.


Point is, it can be a clusterfuck. Check your local laws.


Although, yeah, no, 45mph is well above legal ebike territory no matter where you are, at least in the US.

>>1212342

Anyway...this isn't a new thing. It's a somewhat popular solution to a relatively low-cost ebike. The main downside is that RC motors simply aren't as robust as a hub or mid drive motor coming in at 20-40x their mass. The high RPM also incurs some additional cost and efficiency penalties via extra gearing. Their lack of thermal mass means they're not tolerant of even brief overcurrent conditions. Unless you get an inrunner or other motor made for an RC car/boat, the motor's internals are usually exposed to dust and road dirt.

This can all be worked around, of course, but how exactly you go about it tends to differ heavily depending on what your bike frame and budget is like. You kinda just have to figure it out for yourself. The common solution is to just use them in a friction drive, with a knurled knob attached to the motor shaft and just pressed into the top of one of the wheels. Efficiency is shit, they wear our your tire, and dirt is an even worse problem, but it's cheap and easy.

Also, I'm either misunderstanding or your math is way off. 10,000RPM though a 2.2:1 reduction on a 26" wheel gets you 352MPH. Kind of stretching the use of "approximately" at that point.

Weight
Motors probably 25lbs-50lbs for what you want
Battery is also probably 10lbs if you want to go far.

>>1212105
The biggest rc motors do okay on little razor scooters.

It's the power to weight ratio anon. These little rc motors dont have a whoke lot of torque compared to the weight u tryibg to pull

Is cheaper and easier to just buy a shitty 1,000 hub motor kit off amazon for $160.

They work fine. I have done it. The lithium packs are high tho and between my fat and sla batts. It was a no go.

Alternates woukd be an rc assist at high rpms or a mid drive setup.

But dont let me stop u. Fuckin go nuts and report back if u want.

>>1212159
Nationally a bicycle is still a bicycle if:

2 or 3 tires

Wheels 14" diameter or more

1 brake horsepower or less gas motor

750 watts or less electric power

Must be able to be peddled.

That being said i found a chinese kit on amazon that is 1,000 watt bit has a cut down switch to 750 for on road use.

Gonna build a choper bike with pefs and a shitty unicycle welded to the forks with pedles i can barely reach and will never use.

Fuckem.

18 to drive is bullshit.

I am 16 and have a full time job. I dont want to drag my push mower all over town when i can tow it.

>>1212342
Fuck that shit. I would hide a cutoff switch to the throttle so if u get stoped its peddle assist. And never fake pedle unles going up hill.

My fuck comiefornia needs to break off and sink...

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>>1212345
>he doesn 352mph on his $75 walmart mountain bike.

Better stay in the right lane grandpa. I'm comming through!

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Modern bike cranksets have outboard bearings so the axle runs through the bottom bracket unobstructed. You could get angle drive gears tig-welded to the axle and install the motor in the downtube or seattube granted you had enough space and accessability in the tubing. that way you'd have damn near unnoticiable powered bicycle. They make a motor kit that works like this and it has been used as cheating in competitions already.

>>1212105
45 MPH is the main problem. I've broken enough bones on bikes to pass on this one. Trike maybe, but not on a standard bike. Highly recommend the recumbent trike style to keep the center of gravity lower.