Just add a prop to this design!

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

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.

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

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?

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

I’d know that smell anywhere: Magic Smoke!

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

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

@@elknackebroto7447 it's the insulations on the coil

0 torque tho

this is why EVs better than ICE

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

@@GewelReal thank for info. but who asked?

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

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.

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

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

@@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.

@@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.

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 🤣

@@3ala2Aldeen stop stealing copper wires

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

More impressive that the esc didn't burst

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

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

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

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.

@@GigsVT 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.

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

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

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!

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.

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

but you add more step = add more loss.enegy

Did it have enough torque?

Haha!

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

The motor is way too small

Yup that motor is impressive asf!

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.

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

@@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.

@@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.

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

​@@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.

@@XLR8bg Induced airflow I'm pretty sure

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.

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

Or building some heat sink to drain the heat.

@@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

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

maybe liquid cooling :D

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.

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

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

I want a collab of you two

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

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

@@TreyShawn42 wife mode

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

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

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

Definitely not

@@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.

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

also compare the weight!

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

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.

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.

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.

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.

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

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

@@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.

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

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

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!

What a marvelous idea 👍👍

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

can you say extruded aluminum cable drive exo suit?

Then you could just as well get a bigger motor

@@johntordurkviltsevdal8214 I think it would still be lighter than the equivalent power

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

@@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.

@@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

@@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. ;)

@@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.

probably get a lot more air cooling on a drone too

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

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.

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

@@lilvenaz 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.

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

​@@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.

@@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

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

Torque to speed.

How did you reply 2 days before it was posted?

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

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

@@unnamed47 ahhh that's right

@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.

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.

ukposts.info/have/v-deo/hIWHpqVqno6ep2g.html

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

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.

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?

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.

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: ukposts.infoIZ091JnsDAs

@@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.

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

@@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).

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.

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.

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

@@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...).

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.

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

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

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

@@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?

😂

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

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

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

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

the gears did work, not a motor

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

@@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.

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

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

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.

@@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.

@@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.

@@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).

@@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.

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!

@@modelnutty6503 Exactly!

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

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

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

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

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

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

We have alien technology. 😜

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

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.

@@marsbase3729 have you been at chicken hole base?

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.

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.

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.

Those motors are $14

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

Hasn't he had this issue before? I'm not even a regular bike rider anymore, been 25 years since last and I know that pretty basic requirement.

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

Exactly! its way more economical than a ebike motor!

@@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.

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

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 :)

@@ImhotepBE Same concept as a servo motor.

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"

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

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.