Tiny 1kW Electric Bike Motor

[@justuslm]

When it comes to the motor getting hot, remember that drone motors are designed to have what's essentially an overpowered cooling fan blowing directly onto them at all times...

[@pterodox123]

Just add a prop to this design!

[@h3Xh3Xh3X]

Also the ebike motor has a lot more metal mass to dissipate the built up heat

[@borislipschitz2740]

My first thought, on the first seconds of watching the video was literally "this thing is gonna smoke itself to death at anything near 1kW without that prop". Guess it did better than i thought it would.

[@tychormthorp]

@@pterodox123 clutch fan style, maybe put a small prop on the end of the spindle? Transverse mount?

[@jakubzelenak330]

surely you could just add a small funnel at the front of the bike to divert some air to go right next to the motor to cool it, no?

[@snjert8406]

I'm actually impressed at the fact that the motors didn't immediately combust, especially the second one. Wow.

[@3ala2Aldeen]

I did short 0.8 mm copper wire to a led acid battery, it glow red but still one piece If you wondered why I did that I needed to burn the isolation of the wire 🤣

[@toolbaggers]

@@3ala2Aldeen stop stealing copper wires

[@R.Daneel]

Agreed. This is damn-near a commercial for those motors.

[@leonordin3052]

More impressive that the esc didn't burst

[@jakegarrett8109]

@@toolbaggers He might have been electroplating something with the copper.

[@DoRC]

Something that you didn't mention that's important to consider is that you're probably losing 20% of that power to drive train losses going through that much reduction. Also the drone motor is designed to have a constant stream of airflow on it from flying through the air and the propeller. I bet if you double the size that motor again at a fan to it you really have something.

[@GigsTaggart]

20 seems high. chains are close to lossless and belts are like 95%.

[@jeremoisde9928]

Yeah you have Sommething, unless you go uphill and the Motor Burns😂

[@ChatNoirLe]

From the multiple stages you lose 15-25% depending, a GT2 belt is about 95%, while a chain is better if in perfect setup and condition, or a bunch worse if else.

[@DoRC]

@@GigsTaggart that depends. The faster the belt is moving the greater the loss. You've got one stage moving extremely rapidly and other stage behind that plus the chain. The 3D printed pulleys are probably a bit less efficient than Mass manufactured ones due to the additional friction of the layer lines etc. I was figuring around 8 or 9% for the fastest stage another 5-6 for the next stage and then a few percent for the chain. Youve also got six or so rubber sealed bearings in there which are going to cost a percent or so each. By those numbers 20% is actually generous.

[@DoRC]

@@ChatNoirLe dont forget about six or so rubber sealed bearings at around a percent each.

[@Onespica]

Never expected such a small motor to output such insane power. Cool video!

[@GewelReal]

0 torque tho

[@bozzalnw5357]

this is why EVs better than ICE

[@GewelReal]

@@bozzalnw5357 electric engines* EVs suck with their god awful batteries

[@bozzalnw5357]

@@GewelReal thank for info. but who asked?

[@walnutkraken9430]

@@bozzalnw5357Do you get tired of hearing clown music when you type?

[@Maxzillian]

Arguably one of the biggest issues is none of these power ratings are accompanied by a duty cycle. Just like comparing the tractor to the GTR, the 1000w hub motor can handle that peak power demand for much longer durations than the drone motor. Still, it's absolutely hilarious to see such a tiny motor do all that work. Nicely done!

[@mhenlopotter1612]

Yup that motor is impressive asf!

[@drkastenbrot]

The drone motor power rating is continuous, but its measured with a prop attached. At that power and size it would have airflow around 150-200mph, staying at a equilibrium stator temperature of around 60 celsius. Drone motors are designed to be as light as possible, and they can get away with it because of that airflow.

[@srck4035]

@Hash Frowns it's 100 percent with a prop on

[@Maxzillian]

@@drkastenbrot It would be interesting to see a new pulley printed with an impeller to help draw some air through the motor, but at the end of the day it's asking a lot from some dubious ratings.

[@drkastenbrot]

@@Maxzillian the only smart thing would be using a motor appropriate for the application. rc boat motors are similarly power dense but they use watercooling to get rid of the heat. much easier to provide than 100+mph of air and the torque is also more appropriate for driving a bike.

[@Amy_A.]

A big part of drone motors is that they need the cooling from the drone blades to keep from overheating. I wonder if you could get it functioning more long-term if you added some kind of cooling fan, either directly on the motor like a drone blade would be, or as an external fan directed through the coils. Fun video, thanks for making it!

[@asandax6]

Or building some heat sink to drain the heat.

[@pe5erbarnes]

@@asandax6 a heatsink is difficult, because the outside of the rotor is spinning. The only bit that doesn't spin is the inside and the base, which isn't a lot of area to add a heatsink to

[@enginerdy]

The other aspect is that the data sheet is probably lying, giving peak power instead of continuous

[@Chuckiele]

maybe liquid cooling :D

[@diodazelena3330]

still would burn out, in drone the motor is always spinning with maximum speed because there is basically no inertia, but on bike the acceleration is very long and hard and when not spinning at maximum speed, the air volume generated by fan is severely decreased. Also i seriously doubt, that these small motors are rated for this output power in continuous S1 cycle.

[@NicholasRehm]

Ahh yes, the age old drone motor sniff test. Never fails to indicate that something's not quite right

[@elknackebroto7447]

well if a fuse or w/e part of electronics blows there is a very distinct smell

[@OGSumo]

I’d know that smell anywhere: Magic Smoke!

[@elknackebroto7447]

​@@OGSumo this is what u call the smoke in u momas room after she used that weird glass pipe right

[@RoySATX]

I call that the "Touch and Sniff" method. If either your finger or nose gets burned something is going wrong!

[@03056932]

@@elknackebroto7447 it's the insulations on the coil

[@Johny40Se7en]

Cool idea. Consider adding an aerodynamic duct to channel air through the little electric motor. So the faster you go, the more air it'll get over it, maybe add a little Noctua fan to it too. Should be fine 😉

[@Kimoto504]

Cooling is definitely what's needed but passive cooling won't be enough, as seen here. They'll need some sort of impeller to force air through the motor. On drones they have the props but that's under a far, far lighter load and there's no structure obstructing air flow like on the bike. Having a good impeller pulling air through the motor and kicking it out is probably the most effective approach here.

[@Johny40Se7en]

@@Kimoto504 That's where the brilliant Noctua fan comes in. They move a lot of air and are damn near silent too =)

[@yatzeegamingop]

@@Johny40Se7en You need watercooling for this motor to work properly. These motors heat up soooo much even in proper use.

[@Johny40Se7en]

@@yatzeegamingop A watercooling system would add unnecessary weight though, and copper does corrode, so you'd have to add a heatsink that was attached to the water cooling set up and make sure the copper doesn't get wet. Again though, it would just add complexity to it. Just having a duct made of carbon fibre or even aluminium, then perhaps a 60mm Noctua fan to force air through the motor would be ideal.

[@yatzeegamingop]

@@Johny40Se7en Dude, i am saying even 85mph of ram air is not enough to cool the motors on my racing drone at full power. Why won't you try to understand it ? It's not a 150W cpu, it's a freaking 900W motor. Or better yet, use a hub motor. Like how it was intended. Also inrunner brushless motors have watercooling jackets used in ground vehicles. Tom was just stupid in using an outrunner.

[@StuffMadeHere]

If would be awesome if you built a little bike dyno to see how much mechanical power you're actually getting out. Might actually be worthwhile with all the bike propulsion projects you get up to 😉 EDIT: On second thought, you could EASILY retrofit a bike power meter to do this. Check out powertap hubs. You could build one into a little drum for dynoing anything with a wheel...

[@courtneyconaway3091]

We know what project you’ll be spending the next few months on now

[@vintyprod]

I want a collab of you two

[@MrYrodz]

I can't believe you still have time to watch KZbin.

[@TreyShawn42]

I wonder what you would do to add your own spin on an E-bike!

[@vintyprod]

@@TreyShawn42 wife mode

[@noahagnew6517]

A long while ago I did the math and it was cheaper to use 50 drone motors than one large motor for a car. Never really thought of what would happen. Good to know

[@ziad_jkhan]

Would love to have a look at how you arrived at that conclusion

[@Thewall6110]

If they're at retail price then probably, as you are paying for brand name car parts vs cheep drone motorcycle

[@tysemilicia3931]

There’s no way because how could u possibly set that up, there would be so many gears and stuff that something would have to go wrong, plus syncing them up together would be near improbable aside from the battery and wiring situation

[@tacct1kk715]

Definitely not

[@xaytana]

@@tysemilicia3931 Using encoders and a bit of logic could sync them fairly nicely; though all the motors would be mechanically synced across the set, if you send an identical pulse to each motor it should work as is, you'd just lose efficiencies to disparities in the individual motors as varies in manufacturing would cause this. As for how to have a 50 input single output setup, I'm not really sure, typically planetary gearboxes with motor-driven planets and a held carrier is a good way to link 3+ inputs, but 50 is a bit ridiculous; though with the size of drone motors, maybe a stack of planetaries could work, say 7 motors on one planetary and 7 planetaries into a final planetary, it's only 49 motors but I don't think a single motor would make a huge difference, considering that the sun is typically freespinning as the ring has more versatile use, the sun could be missing for all the system cares, a planetary of this design isn't too far outside of what could be probable. It'd take up quite a bit of space, but so does a proper EV motor at scale. It's not practical at all, and the gearset would massively offset cost benefits, but if someone was crazy enough to attempt a system like this, it would be theoretically probable within this setup that minimizes the amount of gears each motor interacts with. Alternatively a serpentine belt could be feasible, but would probably experience too much friction to be practical, but could also nicely interface with the output more directly; though it'd be interesting to see a double-sided belt and have motors replace idlers, which could minimize friction, damn near cut friction components in half even, as you'd otherwise need a lot of idlers to ensure a proper amount of contact on each pulley in the setup. Again, not practical, but not theoretically improbable. I almost want someone to test it, especially the serpentine belt method, just to show how gloriously stupid the idea is. But this also doesn't explore the nightmare that the driver board would be, that itself would have to be its own rabbit hole of stupidity.

[@ToastyMozart]

You can definitely tell the motors were designed for different applications. Quadcopter motors like that are built for high speed power rather than low-end torque, expect a *lot* of airflow for cooling, and aren't really meant to be running at max output for extended periods of time.

[@Repair_Been]

It burns the wires because it produces extreme polarity changes in the coils with high rpm's as those (around 700 rpm is 100-120,000 (Hz) polarity changes, that is equal to induction heater, with 30,000 rpm that is rocket cooker).

[@homemade_madness]

Yes! i always love it when you combine bikes and stupid ideas!🤣🤣 worked pretty good for such a small motor tough!

[@dontreadmyusername6787]

The power to mass ratio of the motor is ridiculous...

[@nathantron]

You should try using 4 of those motors in a star belt tensioned configuration and see how a distributed load could handle it. You might be able to get the gearing a bit closer to perfect too.

[@DJRCMACH]

this exactly, reduces friction could be run bearing on rotating shaft compound belt reduction and better torque for the real world effects of friction.....and simply 4kw would be more appropriate for load because you don't tow caravans with Fiat 500's

[@Der_Fussel]

Kinda a good idea but then you could just get the standard e-bike motor if we are talking about the size ^^.

[@fkthewhat]

I had a more rudimentary thought of ‘I wonder if multiple motors distributed somehow could work’ and I’d be keen to see it too!

[@PowerScissor]

I can't even guess how many times I've been holding one of my racing drone motors wondering if I could power my bike with it. After some quick gearing calculations in my head, I think nobody has the time to do that...and BAM, here's the exact video!

[@ezrarichardson279]

Haha!

[@ejirokporon5942]

Only Tom would be crazy enough to try oit such mind bougling ideas. I love it.

[@tysemilicia3931]

The motor is way too small

[@TarmanTheChampion]

His channel and ideas make for an extremely entertaining KZbin watching experience!!

[@justinr9784]

"You need one of those little bobbins there sitting up there like that" - British Engineers

[@a.p.2356]

The coolest part about this isn't that a teeny little drone motor can power an e-bike (briefly); the coolest part is that with a motor that tiny, you could absolutely figure out how to hook several up at the same time. That would keep the temperature down a bit by virtue of not having to run it absolutely balls out all the time, and it would make that thing go like a stabbed rat.

[@balasmj]

What a marvelous idea 👍👍

[@lukerobinson3983]

Exactly what I was thinking whilst watching pack 4 together 2 on each side and it could be pretty impressive and still very light

[@kingmasterlord]

can you say extruded aluminum cable drive exo suit?

[@JTordur]

Then you could just as well get a bigger motor

[@lukerobinson3983]

@@JTordur I think it would still be lighter than the equivalent power

[@hz8711]

I think you should add more drone motors to the point where it beats the original ebike, and compare the price of parts used after that. Great video, thank you!

[@loddude5706]

2 wheel drive? Rim mounted ring gear . . . how many motors CAN you fit per wheel? : )

[@CouchPotator]

also compare the weight!

[@dontreadmyusername6787]

I had the same thought and in addition to that adding more drone batteries can result in increased range since they are light and small

[@anthonyrstrawbridge]

Yes, I agree because I'm just too lazy to do so myself. I like the idea of exploring motor rpm and torque without the use of a speed controller. Using switches and hard wiring three motors in differing wiring schemes for example: S1 3M Series, S2 2M Series, S3 1-2-3 Parallel. It would also be interesting to observe the voltage drop of series wired motors in comparison with increasing bus voltages. It worked well for traction motors on locomotives. Quite frankly I like the idea of not needing a speed controller but it would also be interesting to experiment with.

[@ljadf]

I had the same thought, if one motor can do that, two might actually beat the hub motor, and a small fan might then be enough to cool them down.

[@wrathofsocrus]

The starting current is going to be much higher than it would ever encounter on a drone. It would likely last longer if you pedal up to speed before applying throttle. Given the power losses through the drivetrain vs a direct drive hub motor, comparing the power draw of each motor doesn't tell the whole story. The race at the end was more informative than simply listing peak current draw. Great video!

[@rennethjarrett4580]

That was part of my concern/idea, but they should have put a slip clutch on that motor, or one of the belt/gear wheels so when peddling you are not spinning that motor super fast.

[@HaloWolf102]

This would likely be a speed bike, not a recreational one. A recreational one would include very high torque, and low speed. Because people don't like going up hills.

[@remirms2239]

Indeed, with a proper starter though, you could limit this issue greatly.

[@Geniusinventor]

How about using 2 or 3 drone motors that will Split the Load and make it go even faster or make it accelerate faster

[@remirms2239]

@@Geniusinventor That won't really make a big difference, plus you'll need some sort of reduction mechanism then, which will make it quite a bit more complex. Easier for him to have a chip in there that spreads the current over a longer time, like how they do it with starters on AC electromotors.

[@nicholasittzes7224]

Now you need to add a 1KW cooling fan to keep it cooler! 😂

[@Gosuminer]

Awesome experiment. I suspect the problem lies more in the ESC than in the motor itself, because drone ESCs are designed to reach a given speed, not just to apply power. So with such a big inertia of a bike plus rider the motor is commanded to reach a target speed which it cannot achieve for several seconds. Also, drone motors are designed to run only one second on full power because by then the drone will be accelerated and the props unloaded.

[@54l68l65l20l47l61l6D]

probably get a lot more air cooling on a drone too

[@chrisbraswell8864]

Probably way off on gear ratio need another 4 to 1 or about.

[@jakegarrett8109]

Depends on the motors efficiency mostly. If you get a really efficient one, they don't heat up much (example, you may measure 1000w from one, and 1050w on another for the same output, and if that output is 990w mechanical then one is going to be heating up 6x faster and may burn out while the other will run till the bearings wear out without over-heating). Its impressive just how much a few design changes affect those motors, and modern race motors are probably nearing the limits especially when you compare to the older generation (flat magnets, multi-strand coils, bigger magnet to stator gaps), its a HUGE difference. Yes I test motors until destruction, measuring mechanical efficiency, case temp, current and torque curves, thrust efficiency with different props etc. I've been testing motors to destruction just for fun before I ever was paid to do it (that's not my primary job, just one of them). I will say you can also change the timing on pretty much any ESC within the last decade, so if you're having issues with that most of them you can change just listening to beeps and inputting throttle to program, or if they are 32 bit then new flight controllers can usually do a flash passthrough.

[@venasanev]

Are there ESC made for this task? Or one has to go on a limb to design one?

[@jakegarrett8109]

@@venasanev They sell them in any size you want. Want them water cooled? Buy a model boat ESC. Want it power limiting? They've got those too. ESC probably won't even be very warm, they have extremely tiny ones that run 4 motors at about 60 amps (each) that are less than an ounce. The thing that gets hot is the motor. Like I said above, all of them allow changing parameters like startup/advance timings, some allow braking levels etc.

[@tims8524]

These motors normally operate at high RPM. The back-EMF generated at high RPM sets a dynamic limit for coil current. At low RPM/high torque, the coil current is not self-limiting - and unless the controller is programmed to limit current draw, your motor will burn

[@tomaszwota1465]

But isn't it still running on high RPM when the throttle is in full deflection? Otherwise what are the gears for?

[@someonespotatohmm9513]

@@tomaszwota1465 When the bike is going yes, but not when it is standing (nearly still). The other issues is that it is not mounted on a drone blasting plenty of cool air over the motor, which the designers assumed would be the case.

[@randomguydoes2901]

@@tomaszwota1465 it has a total of one single gear and the only way to switch is to get off and replace one of the sprockets

[@tomaszwota1465]

@@randomguydoes2901 I'm not talking about that. I'm talking about the gearwheels that are there to "reduce" the RPM and "increase" torque. I get that there's one "gear" or "speed", or however you'd call it. I may be stupid, but I'm not blind. I just don't necessarily know the right terminology. ;)

[@tomaszwota1465]

@@someonespotatohmm9513 that air cooling aspect I didn't really take into consideration, but I guess you're right. Do you think this would be the dominant issue with this unorthodox application of the second motor? I mean, it may be 1000W (or thereabouts) but that's still a lot of torque that it needs to speed up a bike and a chunky rider on it.

[@ssj3gohan456]

Fun fact: early e-bike motors used to use this kind of arrangement. They had pretty tiny outrunner motors (but configured differently to deal with high startup current - also way better cooling) and a 1 or 2-stage reduction gear, often planetary, to the casing. But as it turns out, once you factor in sufficient allowances for cooling, enough metal to transfer the forces between the axle and spokes and all that, they weren't *that* light. Typically around the 1.5kg mark for a 250W motor. These ended up going out of fashion because of the noise. Used to be commonplace though, I'd say about 50% of pre-2010 e-bikes used this arrangement.

[@nathansgreen]

So if you wanted the lightest possible setup, make something like this with a temperature sensor kill module to keep the motor from burning up.

[@parth_sisodiya]

kzbin.info/www/bejne/goa5o6JpnL2gfJY

[@luminousfractal420]

I wonder if anyone's tried solenoids as pistons? They can pack a hell of a lot of force into a tiny thing.

[@pieterveenders9793]

I was going to mention, if they wanted to try and make their e-bike work with a brushless outrunner they should have used a planetary gear, after all they easily do between 1:50 and 1:100 in a single step and produce massive increases in torque for it. Plus the planetary gear would fit rather nicely in the hub of a bicycle wheel.

[@feilox]

Thanks for the info. I was wondering where the small motors and extra gears went? now with the new single hub motor e-bikes china has been mass producing. I suppose they are def. more efficient. My only question is why dual motor bicycles don't go nearly twice as fast?

[@dhanushkumar9347]

Keep all the 4 motors of the brone ...boom🔥 u clocked 400MPH ..insane❤️‍🔥

[@TedBackus]

as a kid, i had a bike, that had a electric motor on it, & it worked amazingly well. this was in 1985, im certain you could do it easily with modern tech. the one i had, was a traditional bike, with a normal pedal driven chain, but the electric motor was mounted above the front tire. it had a lever, that when you pushed , it would lower the drive wheel which was directly mounted on the motor, onto the front tire. it worked very well

[@bet8467]

Did it have enough torque?

[@chrisrathjan1501]

In my experience drone motors are rated using phase amps while ebikes use battery amps. Short duration peak pulse vs RMS continuous or average power. Would have been interesting to see how much battery power they were each using.

[@zaxmaxlax]

Its peak current(60s) according to the manufacturer. Theres no away that tiny motor with tiny wires can sustain 50Amps.

[@deadmantwen]

​@@zaxmaxlax once the load is going motors draw less amps. so at max speed or finishing acceleration they're not pulling 50 amps to keep going.

[@erikd6124]

@@zaxmaxlax motor W and Amps aren't realiably. They aren't measured the same. The weight of a brushless motor is a better indicator of its actual power, then it's specified watts and Amps ratings. Then comes the kv and V of course too

[@zaxmaxlax]

@@erikd6124 The datasheet tells pretty much anything you need to know.

[@neilcollins5224]

Torque to speed.

[@AlexanderBurgers]

Brushless RC motors can typically run at somewhere between 3 to 5 watt per gram, depending on the efficiency and duty cycle and cooling. An actual 1kw motor would therefore be more in the range of 200 to 333 gram, or more. This 40 gram motor would realistically be a 150-200 watt motor. Like you said, it's the electrical rating, perhaps they just figured short circuit current * battery voltage = power or something, or just claim bigger numbers because bigger number = sell more units. A slightly bigger RC motor can totally power an e-bike without melting. :)

[@KoeiNL]

Considering how many amps these things pull the rating can be accurate. The ESC's that control these motors can be like 50A (with higher burst) and use 6S battery packs (22.2V nominal voltage), so if you go full throttle and pull over a 1000W. And you need those kind of ESC's, because if you don't they will just go up in smoke. You can also easily figure out how much watt they are pulling by just seeing how long it takes to run down xxx mah on your battery. Remember, these motors have 5" cooling fan sitting on top of them in use and are on an object traveling somewhere in the region of 120-160kph. Still I wouldn't run that at full power for long ;). Here is a short video that really shows what kind of insane performance you get from these motors: kzbin.infoIZ091JnsDAs

[@LuLeBe]

@@KoeiNL I think you can't just measure battery usage because that's an average, acceleration takes mich more power. And the power requirements for these short periods can be quite insane but they can't keep that up for longer. If they had continuous 1000w that would also mean around 100-200w of heat output, that can't be cooled without a fancy heatsink. I have some RC cars, they have 120A 6S ESCs so up to 120*25=3000W and obviously the RC car doesn't empty a 5000mah battery within 2.5 minutes. The batteries also couldn't handle the load if it was continuous.

[@skeezixmccat]

I'd love to see a bike powered by an 8s Xmaxx power system 🤣 I bet the bike could do wheelies lol

[@KoeiNL]

@@LuLeBe Doh, of course it can't run at 1kW until the battery is drained. But the peak power hits 1kW no problem, and because of the fans and the speed the thing is moving at the heat is less of an issue than on RC cars where the engine isn't getting direct airflow and reaches lower speeds. Battery would be something like 6s 2200mah with a 40C constant rating. That's 88A continuously. so a little over 1900W continuously with much higher peaks. You are probably looking at about half of that as an average when flying freestyle or racing which would result in an empty battery in 4 minutes (you will never completely drain it of course).

[@diymaster101]

No going to lie that motor is really powerful my god I never expected it to be that good

[@jasons2562]

That little motor getting so hot was dealing with A LOT of constant drivetrain load/resistance too which is compounded by how fast it spins and has to spin the various connected belts, gears etc. I think that is a very different constant load than it would experience on a drone especially when starting at lower rpm's on the bike to get it moving.

[@Skywalker8510Too]

Plus on a drone it’s got an oversized cooling fan strapped to it

[@AmirSaboury]

This is one of the coolest thing I've seen in a long time! Good work!

[@robinson4470]

How did you reply 2 days before it was posted?

[@AmirSaboury]

You can join his patreon for early access: www.patreon.com/tomstanton

[@0m1d]

There are better and cooler projects in KZbin you just have to have time to watch and research.

[@robinson4470]

@@unnamed47 ahhh that's right

[@jasonpatterson8091]

Very interesting. :-) My immediate thought when you said you were going to use a 1kW drone motor for an ebike was that it would cook itself. Even if it's 90% efficient it's still got to dissipate 100W of power as heat, and in such a small package without a spinning blade actively cooling the thing, it literally must get really hot really fast. I honestly didn't think it would last long enough to get going on the road (which kind of happened with v1), so I'm glad to be proven wrong on that count.

[@niravapurv4578]

I dont think you got that right. I am not 100% sure, but I have read articles on eficiance of Electric cars Vs hydrocarbon/fossil fuel cars. And as i understood it the excess heat is basically the lost energy. A fossil fuel car is very less efficient(about 33%)(/67%is lost and is transformed to basicaly heat), therefor it generates heat. So a lot of the energy when burning the fuel in the pistons go directly to heat and is not helping to move the pistons. Newer cars thend to be more efficient those generating less heat. Electric cars have ofc a different system where electronmagnetic energy is used to generate circular movements that connects to the wheels... where some energy also is lost while transporting electrisity and also when charging, the energy lost in the process of moving the wheels on a electric car is very less(about 10%is lost and transeforms to heat)... thats why the engine creates less heat and electric cars tend to be very cold in the winther. Its the same on wolfram/glowing bulbs (dont know the right word in english) ... the energy lost in these bulbs are around or more than 90%, thous they get realy hot, while a buld witch use light emittind diods (led) has an efficiency of 50% or slightly better.. so they are many many times more efficient and create much less heat. Its very probable that the reason the small engine gets so hot is that the size of the engine is not ideal for how much resistance the engine will get when trying to move this bicycle the momentum inside the engine needed with this bicycle is higher to acctually get it to move than what you need in the engines of the drone.. its almost like you trying to drive a car on to high gear... thats why it moves slower and more energy is just lost and generates more heat than thrust although the engines can use same amout of watts, they are still designed to move a more heavy object (the bicycle) or a more light object (the drone). The engines in the drone is actually spinning in the air... so engine gets less resistance to get a very high rpm.

[@niravapurv4578]

sorry, i read wrobg in your messag, i read 1000w as heat in instead of 100w.. ofc you are right.. if engine is electric and use 1kw.. the exsess energy is normaly around 100w (10%) tho i think it will be higher in this case depending on several factors like the gearing.. if this ebgine can work in a rpm area ideal for it.. and if the engine is strong enogh to handle this load/resistance.. according to different physical factors its likely that it will not opperate optimaly and lost energy to heat will be higher than normal.

[@BruceS42]

For such extreme gearing, have you considered using a worm gear? That would only work one way, but for taking a very high-speed input and producing a much more manageable output, it should be good. Anyway, fun video, and well considered project. I look forward to more.

[@americansongdog]

Just as a thought you can run 2 motors through a gearbox together to drive a belt. At that point you can either extend the lifespan of the movers or add another reduction for more consistent performance. A better heatsink would also do you wonders on those usually air cooled moters. A water jacket would be super cool to see

[@tech_universe1218]

Had the same thought after watching the video. Maybe another video trying it out would be awesome

[@imperialsecuritybureau6037]

Yeah as they’re made to be used with a propeller they’re designed with the expectation of LOTS of cooling being available… mounting a fan on the shaft (if there’s still room after the pulley) will help a lot with the temperature and performance. And yes a geared system would be great. There could be 4 or more arrayed around a central gear (>4 pinions driving one gear) and it wouldn’t take up too much room if done right. That would make for an impressive machine… but would require 4 ESCs as well. Still, pretty cheap way to do things!

[@imperialsecuritybureau6037]

Also the watercooling is an option on larger motors of this type, from the 6384 (63mm dia, 84mm long) up I believe, I.e. the 80100, 83100, 12090, 120100, 154120 etc.

[@SodiumSyndicate]

all of that is expensive, heavy, unreliable and inefficient compared to a simple hub motor@@imperialsecuritybureau6037

[@aozoraaoi3745]

but you add more step = add more loss.enegy

[@Skyentific]

Drone motor has PEAK power 1kW, and E-bike motor has RATED power 1kW.

[@TomStantonEngineering]

True, but the drone motor is rated to 1kw for 180 seconds, which I thought would give the ebike a decent competition considering it only takes a few seconds to get up to speed. Riding up a hill continuously would be another story haha

[@krotson6767]

The drone motor would be useful to arm yourself with an additional heat sink. In its natural working environment, the rotor blade cools the entire engine. Thanks to this, it has a lot of power all the time, and not only when someone is not using it intensively. A simple solution would be to use a planetary gear instead of this type of gear ratio. And when it comes to the speed test, you would have to count the motor pull of the electric bike to calculate the gear ratio for the drone motor. Then the fight would be fair. It also seems to me that apart from the mechanical damage to the coils of the drone's motors, the neodymium magnets were also demagnetized. Neodymium magnets do not like high temperatures, so the bike's power could have been lower for that too. But I am not a specialist in demagnetizing neodymium magnets. I would fix what needs to be done and make another movie about it. Regards.

[@jakegarrett8109]

Often you'll see very little loss until complete destruction, once it gets that bad you'll instantly notice it. Source, I burn a LOT of motors both for fun and professionally (and yes I measure the efficiency decrease after abuse). There is a small amount of drop, but its pretty negligible for most applications.

[@felixiaccarino8399]

i always wonder if i could do a 5km/h vehicule with tiny motors and lots of torq, and few motor baterys. can be?

[@krotson6767]

@@felixiaccarino8399 Yes, and it's best to use a planetary gear.

[@felixiaccarino8399]

@@krotson6767 any other advice other than the planetary? im from an overexploited country so resources are limited here

[@krotson6767]

@@felixiaccarino8399 Ordinary belt transmission should also work. The planetary gear can be found in the screwdriver in the garbage can. If the screwdriver motor, not the gear, has burned before. What oppressed country are you from?

[@TheFurious74]

And still when you look at this motor size... That's impressive! Such a tiny thing can pool a man on bike at 30 km/h!

[@TremereTT]

it's like Super Sport motorbikes. these tiny engines are basically used up in a few years because 10000 rpm are just not a sustainable thing.

[@alanrowe8233]

Love the fact that you have given it a go, very impressed with the sheer small-ness of the motor and it actually drives a human along! I notice you have 'skinny' tyres and a flat, smooth surface. Being a keen cyclist and being very aware of the leg-power needed at times, I dare say the motor would go 'phutt' if you had a hill and some more drag on the tyres! but keep up the experiments, fascinating to watch.

[@alexmin4752]

@will b IMO, it's not the motor that's lacking. Even if we assume the motor is EXTREMELY bad and has efficicency of 50% (which is atrociously low) you're still left with 500 watts. Meanwhile, all electric bikes in Europe have measly 250 watt motors (due to regulations) and they are still quite fast. What you need is a better reductor and torque delivery mechanism. Use a planetary reductor made of steel instead of plastic pulleys and belts, add a small propeller to cool the motor and it will run fine. Also, since the power vs RPM curve of such motors has a stark spike near to maxRPM, you'd want to connect the whole assembly in the same way as mid-drive ebikes are made so the motor could benefit from adjustable gears ratio (with the derailer). If you manage to keep it running at high RPM the bike will be fast as hell.

[@iandavidson99]

Would've been nice to have had a power meter inline to see out how much power the ebike and the drone-motor ebike were *actually* pulling

[@toolbaggers]

Watt meters for testing the drone motors are actually pretty cheap.

[@genioee]

@@toolbaggers Sadly, as tom indicated this can give you only an estimate. The mechanical power would be interesting - you'd have to measure the output torque and velocity. But using some sort of drag-race can give a rough estimate of these quantities (at least in comparison, due to friction and weight...).

[@ClappOnUpp]

Actually, if you got that bike going with the wheel spinning 30,000 RPM, you would still be going around 800 mph slower then the se 71.. you would, however, be traveling at about the same top speed as the f-22 Raptor 😅

[@paddycunningham5011]

A few times in the video the chain split-link is visible and you have the split pin(the springy bit) on backwards, this would encourage it to release and fly away when the chain rubs against something. Love the engineering behind this project, keep up the good work :-) If you're ever over in Ireland we could do with some ideas on how to finish our trike project with a 110Hp 2.0Hdi automatic fitted :-D

[@GRBtutorials]

I think part of the reason the first motor didn’t work well is that drone motors are sensorless, so it needs no sensors, but it doesn’t work well at low speeds, making it stall, which resulted in the coils burning out. You could try with a sensored motor (with a corresponding sensored ESC), but those tend to be larger and more expensive.

[@cebruthius]

Don't these rely on the airflow from the propeller for cooling?

[@XLR8bg]

​@@cebruthius I wonder how much airflow they get from the propellers, considering the blades usually start outside of the perimeter of the motor. I have an Air 2 drone and above the motor are the two 2 pins that hold the 2 blades of the propeller.

[@cebruthius]

@@XLR8bg Induced airflow I'm pretty sure

[@wtfiswiththosehandles]

Nah, it was moving with no stalling/cogging, so it was fine. Windings were burning because of high sustained current. That motor can do 1000W only for short periods, with such thin wires and low voltage it is not designed to survive operating at actual 1000W for any longer period of time.

[@YolandaPlayne]

Dude didn't even inflate his bike tires, he's not going to understand you.

[@Exyvia]

Love this, definitely plausible to make this work, stacking 2 motors with decent cooling would make a compact solution.

[@mikemackenziegrieve]

I gotta say I'm curious how well 2 motors would fair heat wise too.

[@natandirt]

or like 50 of em, would be the same size as normal ebike motor lol

[@nicholasaudia4245]

I've been stuck wondering if I can get a decent simple gearing with a chain driven slipper clutch mounted up to a diy e bike to hit around 140mph

[@Flanesgourmetsofiniel]

You shouldn't do that even if you could

[@tex4217]

@@Flanesgourmetsofiniel Ratio

[@idonthaveskill5054]

I'm no engineer or anything, but I feel like this could be used to maintain speed once you get there as opposed to starting from a dead stop. I'd assume it would put less stress on the motor that way

[@oadka]

Exactly! its way more economical than a ebike motor!

[@casper2501]

@@oadka I would treat this motor as little helper while im doing most of the job while moving in desired speed, this small motor is good for keeping speed, but not for starting to get moving.

[@BrightBlueJim]

Which works until you try using it to go up a hill.

[@RSpudieD]

Nice! That's impressive considering the size of the motor. I like the look of the belts and gears, too!

[@NeilStainton]

Great video Tom. It would be wonderful if you would do this experiment again using a 300g outrunner with approximately 15 times lower KV. You could get rid of the gearbox increasing the efficiency for probably the same weight. I think that would actually be an improvement over the hub motor, which actually is a brushless motor built into a planetary gearbox.

[@Eden_M]

The hub you see in this video is a direct drive hub, gearless.

[@boarattackboar]

Funny thing is, if you keep making optimizations like this you'll just end up with a standard ebike eventually

[@hinno95]

everyone talks about the cooling fan of a drone. But you guys didnt pedle at all. Just pedel a little and it wont get so hot from starting up.

[@ahaveland]

Tom, I tried to do this 6 years ago with a 400 kv X5 outrunner motor rubbing against the rear tyre - it worked for about 2 mins before burning out. Heat dissipation is a problem! Thereafter I got a proper hub motor which can deal with a lot more continuous power! I took the motor apart, photographed the windings and rewound the coils and works as good as new. Took a few hours though! If it gets too hot it could destroy the magnets, and that's a bit more difficult to fix.

[@heavyweather]

275 kVi 22,0 Volt ~ 6000 rpm). Diameter of the roll is 51 mm (circumference~ 160 mm)

[@DavidBrown-wh3nk]

Really like this one. Those tiny motor power ratings always had me wondering "what if?" Very cool to see

[@jimmysyar889]

Same. Always wanted to see someone do this. It should in theory be just as good

[@spammy3164]

@@jimmysyar889 although with the extra gearing you do introduce lots of friction and power loss so would always be less

[@phizc]

Also, the first drone motor coat around 25 USD, while the hub motor is probably more like 150-200 USD. Would be interesting to see how good it could get if money is wisely spent maximizing perf and cooling with an equal budget 🤔. DIY or BUY? 😃

[@JWQweqOPDH]

Ignoring special discounts/deals, the hub is superior because of the combination of less battery use (due to less heat and noise energy waste), higher mud tolerance, and not needed replaced often. The people who make the hubs could just as easily make smaller motors like the one on the video, but choose not to.

[@Blox117]

the only drawback for a hub motor is the increase in weight. but even a mid drive system has a significant weight penalty by adding chains, gears, and attachment hardware.

[@cinemoriahFPV]

Those motors are $14

[@dushyantpathak5564]

Bro you make it possible i was laughing hard after the first attempt like your cameraman hats off to your hardwork

[@artytomparis]

There are some amazing things happening with the motors that are used in electric skateboards. I ride an electric pedal bike and often see people going up hill on electric skateboards at a decent speed.

[@marsbase3729]

We have alien technology. 😜

[@ianmangham4570]

I fly up hills on my ebike and I'm 117kg, I have a 1000w rear motor and I put 55v through it at 30 Amps 👍🇬🇧 just over 1500w

[@Eden_M]

The average e-bike controller is limited to 250~500w, e-skates are in the thousands. Using a Vesc on my e-bike with "Field Weakening" I reached 60km/h on flat road and 40~45km/h uphill, with a standard 500w hub motor, it got the system pulling 2000W at 48v, without any overheating.

[@ted_van_loon]

@@marsbase3729 have you been at chicken hole base?

[@johnwest7993]

I almost hit a curb in my car the first time I saw an electric skateboard racing up a hill on the sidewalk beside me. It looks sooo weird.

[@Reddesertsteelcorporation]

I already know that he's gonna somehow get this to work

[@Hippida]

I remember a few years back, Tour de France started to use equipment to discover electric engines, typically hidden in the pedal crankshaft. So, it seems possible to use a fairly tiny engine to assist. As for using a tiny engine to do most of the propulsion on the other hand.... yeah, it would need much more raw torque

[@joejoejoejoejoejoe4391]

Considering the budget of some of the teams, and what's at stake, I presume that they could buy far more sophisticated motors, and use a planetary reduction gear box. Perhaps mount the motor in the downtube, just under the water bottle to use it to dissipate the heat.

[@xxportalxx.]

@@joejoejoejoejoejoe4391 I mean swap out the enamel on the windings with a higher temp polymer or ceramic and you'll already be able to push it harder longer. Next use flat ribbon conductors instead of cylindrical wires to reduce skin effect loses and winding errors (most cheaply made coils will have messy windings that actually reduce efficiency). There's probably more expensive rare earth magnet varieties that can hold a stronger magnetic field, and lighter/stronger metals like titanium to make the stator/rotor from. Higher quality bearings would probably contribute as well.

[@joejoejoejoejoejoe4391]

@@xxportalxx. If you have a really big budget, you could have silver windings. My thoughts of placing it under the water bottle was because they use thermal imaging cameras to detect them, you could put some ice in the water to offset the heat. I'm not sure you'd want it too powerful, it would draw attention too much.

[@xxportalxx.]

@@joejoejoejoejoejoe4391 oooo silver windings is an excellent addition, not even that expensive really, I use silver power straps at work actually (granted at my work money is no issue lol).

[@joejoejoejoejoejoe4391]

@@xxportalxx. Instead or round wire, could you use square wire for them, very carefully hand wound? I guess not much of an advantage over foil. Perhaps pole pieces with slots in ( like a stepper motor ) might increase the tourque, but require a very high frequency, which would be limited by the inductance of the laminations, unless it was used only like a stepper motor at low speed, and went over to use the pole pieces as one at high speed, in some stepper motor/BLT motor hybrid.

[@brackcycle9056]

When it runs at full speed on the drone , it generates back EMF limiting the current. When its tuning slow when the ebike is moving off , no back EMF so massive current . Also the drone , isn't putting a Kw into the motor continuously , or drone would go skyward quickly. If you knew the drone weight you could calculate the actual hovering power & compare that to the cycle acceleration power & see how much you torched it.

[@fernbear3950]

That's super fun! I wish I could have seen a "with pedaling" top speed as well. And a temp sensor with an auto cutoff would be nice too! I think it's really nice, too, because you can have a little boost for hills in a commute and such where you don't want to get your suit sweaty, but don't have to carry around a full battery/motor assembly at all times.

[@Bikes_N_Adventure]

A slightly larger drone motor and I'm sure it would only be better!

[@Vic64Y]

What's impressive it's the fact that, yes, such micro motor... It works! And, we have to keep in mind that such tiny drone motors are designed to be cooled with a continuous flow of air coming from the propeller.

[@nikostalk5730]

the gears did work, not a motor

[@Descalibrado_]

does the heat comes from the amps that passes through the coils? or they heat up from the spinning alone?

[@Vic64Y]

@@Descalibrado_ From Quora: In general, DC motors tend to get hot when they’re under a heavy load and drawing a lot of current. The more amperage is flowing through a wire, the more waste heat will come off of it, and this applies just as well to the coils inside a motor.

[@Descalibrado_]

@@Vic64Y so the heat is from the electrical resistance of the high current In thin wires, thank you a lot!

[@akiramiller9025]

​@@Vic64Y brushless motors are ac but controlled by pulsed dc

[@craigcarmichael5748]

Even if all else was equal and even if the drone motors wouldn't burn out, the two sets of linkages would lose some percentage of the power, while the e-bike motor is direct drive - no transmission losses. So more power in the drag race, longer battery life. Nice builds, nice tests, nice video!

[@kevinburke6743]

Don't reinvent the wheel! Bolt your slim small motor onto the side of an 8-10speed in hub gearbox. Use 1st, 2nd & neutral as normal & 3 to 8-10 as speed gears. You may have to reconfigure the twist grip & electronic shifter! Alternatively instead of mounting in the back wheel. Put a front sprocket with the correct No. of teeth for your purpose! You can always go up or down a tooth or two, to suit. That way you can have a STD fixed or freewheel at the rear.

[@Divyesh_Sinha]

If there was a way to achieve that 80:1 ratio without any transmission loss Then it would have performed quite similar to the hub motor Cause the hub motor literally has no transmission loss If you calculate the power loss on your gearing and add it up to 1kw and use a drone motor of that value It should be pretty equal to the hub motor

[@MCsCreations]

Damn! That's pretty surprising indeed, Tom! 😃 Fantastic work!!! Now imagine one of those big 30+ sized motors! Anyway, stay safe there with your family! 🖖😊

[@modelnutty6503]

might be fun with a loose/unused 1500kv 3650 w 5mm output shaft here. could be done with standard available pinion+spur gears to keep it simple. the size and fairly low rpm/volt might be close enough to appropriate. with 3S or 12v about 18k rpm free spin, calculate reduction for 16k rpm 18 mph. -because if you were pedaling 18 mph is pushing pretty hard!

[@MCsCreations]

@@modelnutty6503 Exactly!

[@ColinTimmins]

Honestly that was a really cool experiment. I wonder how far a person can go with the idea of specifically making a small lightweight motor for making an E bike from any bike. Fun stuff. =]

[@Channel-tr1hx]

looks like not using a reduction gear in the big motor is a wast of mass. probably using 4x lower kv and something like 1:20 ratio would be optimal in terms of motor weight to torque

[@Vok250]

Eskater do this all the time. The key is to move fast enough to keep the motor air cooled, to buy reputable brands, and to use the right gear ratio. Lower KV ratings usually work better too.

[@markuspetersen6072]

Thanks for making this video. I was always wondering if a huge gear reduction would make it possible to use tiny motors to power bigger machines irl. Not just on the paper.

[@ImhotepBE]

ohh yes...its possible.. I have seen the big structure(water treatment plant) run by very small motor with huge gear reduction...I think motor was about 3-4kg (no more then 1,5kW ) and gearbox+reduction box about 300-400kg... the whole structure (big frame) about 1-1,5k kg.. and this frame was running in the water.... so yes, its possible :)

[@techguy5601]

@@ImhotepBE Same concept as a servo motor.

[@RGIIIBOXING]

It's a waist of time" They will burn. Up even with 5//6 of them...We did the same thing with our bike using a Hoover board motor" 250w on both sides...one lasted a almost 2 months..the other motor almost a week more" Then we got a 750w set up" and it's been good for 6 months and still going...we went on and got a 2000w brushless motor kit and we're going to set it up in a few days"

[@ririfiri3243]

It is possible but there's more losses on gearbox so people usually don't do that unless needed

[@Buciasda33]

Gear reduction means friction. A huge gear reduction can overpower a motor. I think there's a lego channel where you see small lego motor lifting 100kg or something.

[@TranceFur]

Would be cool to try this with other RC motors. Like maybe a 4274 size Hobbywing motor that’s meant for 1/8 racing trucks. You could run up to 22V batteries, and that bike would probably fly, haha!

[@alphaadhito]

Well, you can see the original Tom Stanton DIY ebikes waay back then uses that kinda RC motor haha

[@BloodxSoulZ]

some are even rated for 8s Lipos as i know edit: Ive searched and found BL motors for 1:5 RC cars that are rated for up to 12s Lipos... so 44.4V rating/50.4V fully charged. It said 5.5A consumption at idle. ~275W without resistance? 650kV which still is 33k rpm with the 12s. There is no rating for stall current so i dont know the max. consumption. Without gears it should have somewhere between 180 to 300N torque

[@OnlyUglytroll]

Dude... I have been watching your vids... you are great. I love how you approach things

[@jasonpeace1991]

Right Tom its time to combine two of your projects to get the tiny motor to work.... It's flywheel time Yeap spin up the flywheel you had using the tiny drone motor then use that as a boost for the bike

[@ur_quainmaster7901]

That's... a really fun idea! Would pair well with the low duty cycle of such a small motor.

[@llejk]

I think it would be really cool to find some low rpm high torque motors (maybe from 1:10 RC trucks? ) and design a 2WD bicycle. I have a front driven ebike, and i love how it tracks on sandy paths like beaches or even climb when i coordinate carefully with pedaling.

[@EagleFPV43]

This is what i was thinking, rc cars have motors that are larger in size and with much more torque but run on the same batteries

[@markvermaat652]

Great vid. This is how inventions are done. Experiments, improvements, building things. Love to see this

[@kenromaine2387]

The RC Drone motor is designed to run in an extreme airflow to cool the motor. The prop wash over the motor when on a Drone will keep the motor cool.

[@AJ-Palermo]

I wanna see this with four motors! And perhaps gearshifting would help with the overheating issue

[@timehunter9467]

I was waiting for something to burn, I’m amazed at how “well” it did for a tiny motor!

[@christeschke9844]

stack 4 of them around one gear to gain 4x torque for those starts. Also will benefit spreading the cooling. You could also mount the motors not on the gearing, so tensioning the chain will not effect shaft strain on the motor.

[@UNKNOWNPERSON-kk9kd]

The graphic of the bike moving past the SR-71 made me smile. BTW: You're riding on the wrong side of the road, son.

[@johnrobholmes]

You went about this logically by starting with gear reduction needed. These sort of projects were very common 10 years ago on the endless sphere forum. The biggest issue is the thermal mass of the small motor and small flux gap area. It can go from ambient to 100c in seconds. From experience, you need a motor that's about a half kilo to have enough thermal mass. Still undersized, but with proper gearing and top speed would be pretty reliable

[@Eden_M]

Bro! The classic 80100 outrunner belt drive e-bikes were monstrous, I've been wanting to build one for years, with the right voltage/gearing, the speed you can get out of the 80100 is unlimited!

[@johnrobholmes]

@@Eden_M endless sphere has so much ebike history

[@michielshub]

Nice video and it also shows how complex these mid-mounted e-bike drive trains must be to handle all that torque, peddling, free weeling, etc.

[@theleader4532]

7:18 it sounds like a mosquito 😁

[@ronniepirtlejr2606]

Imagine if that bike head 2, 3 or even 4 of these Motors. How efficient would they be?

[@3DPDK]

I have that same 1000 watt hub motor. It can "sink" 1000 watts but the motor controller that comes with it is throttled to 750 watts, Many third party 1000 watt controllers are also capped at 750 watts. (some can be reconfigured by a software override) 28 to 30 MPH on that hub motor is typical, but by default it never receives more than 750 watts. This is one reason the hub motor barely feels warm - you are only using it at 75% power - helps the motor's windings last longer.

[@themoss7115]

Impressive! But if you count in gearing as the part of the system, I bet the classic e-bike motor would win on overall efficiency.

[@tonyhoff86]

Super cool. This would be very interesting to see how it works as a pedal assist system rather than full on electic scooter mode. It would be interesting to see if the drone motor could take the edge off of pedaling into a headwind or up a large hill while coming in at a much reduced weight to a hub motor.

[@modelnutty6503]

by driving directly to the largest front sprocket (one way bearing at output) it could be pedal assist, and be making use of the rear spindle/cluster. 15-18-21 speed mountain bike would have 10-12-14 gears available like that. it does need a bigger motor to start with, maybe 1500kv 3650 size.

[@DianneStudio]

amazing video .. wish to see to put a fan for the motor can change how much hot it can reduse.cheers

[@msamour]

Next on the channel, can we power this 8 ton bulldozer with 4 drone motors? Stay tuned and find out!

[@jaystarr6571]

LOL. Then...Can we power a Nuclear Submarine with an electric toothbrush motor?

[@fromthepeanutgallery1084]

Great work. Fun. Sounds like a mosquito as it passes. 8:00

[@MrCameraJunkie]

Ever thought of using a drone motor to spin up a flywheel, and have the flywheel power the bike? Great video

[@joblessalex]

Cannot believe that you can get that to move anything haha. With a triple the size motor, you could probably make a reliable bike.

[@waynenewberry1032]

Fun trial- I know its late, but modeling fan blades into the first pulley would help with cooling.

[@danwei41]

You actually built what I had in mind for long time! Awesome to see it working! Seeing that poor motor be like "I keep a blue flag hanging out my backside" :)

[@hinova77]

You are a real engineer. Actually no need to huge engine for bike in real.

[@scottrich976]

There are some of those motors with a fan milled into the end bell. Still Going to get hot but will aid the cooling

[@BuilderBasti]

I'd strongly advise putting some type of casing around pulley systems with such high rpm in the future. You don't want a belt to hit you in the groin (or worse, head) going like 300mph

[@olmstead25]

I have always wondered about doing this. I thought it would be best to use a motor designed for a electric helecopter though as the case is designed with a fan to help cool the motor.

[@ChemicalArts]

I think this warrants the use of the unit of measure: miles per burned-out-drone-motor. Also, headphone warning!

[@genioee]

Dear sir, I would argue that nothing warrants a unit measure containing any of the imperial cooking pan diameters. But the km/motor coil burnout I like :)

[@Reaperman4711]

6:05 Now imagine that instead of going with a slightly larger drone motor for more torque and less rpm, you used one the size of, oh I dunno--a hub motor? 😜 Still, worked better than I expected, for sure. 👍

[@YourLocalRailfan]

With Tom Stanton anything is possible

[@w-4258]

It seems like Ye'old friction mount on the back wheel would be good for this. You could also engage / disengage like the old dynamos used to do.

[@ruslbicycle6006]

There was a very interesting kickstarter that was claiming to do this about 5 years ago, mounted under the BB, and having a software controlled engagement, battery in the water bottle cage. beautiful concept, I don't know if it ever got made (I doubt it) They were asking about 700 euro for the bare bones delivery tier. I always felt a little tempted by the concept, promising to be the easiest ebike conversion to a regular bike. Maybe one day it will be practical.

[@sargfowler9603]

A lower kV motor might help here. Something like 200kV rated at 4Kw or so. You could then run it below power on a lower voltage and hopefully avoid overheating. You wouldn't need as much gearing. Talking of which, what was the RPM of the motor on the high speed run? Also add a fan to force air over the motor via a ducting of some sort. A great idea though!

[@heavyweather]

That's how it is done and it works without cooling. That are good stats. Add-E uses 275 kV , 22,0 (~ 6000 rpm) for their direct drive (wheel). The roll on the outrunner is 51 mm in diameter (circumference ~ 160 mm). That's a reduction of 13 on an 18-622 wheel.

[@BrettLipton]

Tom, have you considered trying it with 2 motors to reduce the stress and increase the total torque and power?

[@bismuth7730]

Brett, have you considered he could have just gotten a motor twice as big instead?

[@XavierBetoN]

Sorry I had to rewrite my comment! I initially said you could use tires as if it's a 29" cog but due to mud and tire wear issues, I gave a second thought on the idea. What if you could use rims instead? Go with disc brakes, remove the V-Brake, and 3d-print a multi-piece gear at the side of the rim where normally brakes touch. Motor will less likely to get wet and there will be no additional tire wear. Now, you could also use silicon rubber wheel instead of a gear at the shaft of the motor, hence eliminate the need of 3d-printing a 29" gear. I'm an engineer myself and working on a similar project. My only issue is to find proper ESC for my project lately, which you solved that one out. You might work it out before me if anything. Goodluck!

[@XavierBetoN]

You could also use v-brake levers as a clutch to disengage the motor when unnecessary to increase the free-wheel experience