Hey guys, so I’ve been trying to conseptualize why hub motors have so much less torque than pulley driven setups. If you had a 200kV motor, and use a reduction ratio of 2:1, wouldn’t it preform the same as a 100kV motor with a 1:1 ratio?
What limits hub motors? Is it the fact that they have a tough time dissipating heat? Why do they usually have much lower amp limits than outrunners?
Worst part about the hub motors imo. Is the fact of urethane slippage. Most in part due to heat. That’s why you should run with higher voltages to use less amps and less heat.
It us not all hub that have urethan slippage, Hummie hub don’t slip… but the heat reduce the power. Also, Jacob hub have enough torque that they can trow you to the ground. IMO hub motor are the future, but the product available on the market have not been design for speed and torque in mind, they are the first generation of there kind… wait for 2017 
More volts in a motor won’t keep it cooler
I’ll be selling hub motors with the most power before 2017. While info isn’t forthcoming about what exactly would make the @onloop motor the most powerful it’s a safe bet they won’t be when they come out (Variables being stator size, magnet strength and temp ability, and airgap width) They also won’t have the biggest (NSK)bearings. Or the fewest parts that are solid steel (1140 and 1020 steels) with no little screw holding the motor together. Or the cheapest price. Or a lifetime warranty on the mechanical parts sans bearings.
why more volts won’t keep it cooler? is it because then the motor needs to be lower kv so thinner wires and more resistance?
less kv doesn’t always mean more torque, depends on copper content. higher reduction gearing helps the motor get to speed and prevents heat from building up as fast as direct drive setups like hubs. Also note that hub motor are outrunners as well.
I agree with @Hummie. It has been my experience that higher voltage means less amps but doesn’t mean less heat. Guess it’s not just amps alone that cause heat.
So if you had a pulley setup with a 1:1 ratio and a 100kV motor, and a hub motor with the exact same specs; are the only factors that give the pulley setup an advantage urethane slippage and heat dissipation?
If so, then the new Enertion heatsink hangar should go a long way towards fixing that, and his motors would have the same performance as a pulley setup. Or is there something I’m missing?
I’m looking forward to it. My next build is a dual hub motor build, 12s4p.
Might not be until summer tho, the CGT 2-1 cost me a damn lot, got the Trampa build on its way, preordered two BBv2 (stupid I know, sold one already, still waiting for my 2nd one, preordered the 2nd one two months ago)
I hear promo for Hummie Hubs here. We dont know the Enertion ones yet, but being sold with the Raptor they will back it for 12 mth at least. It it fails within that time its covered and you would think if you had any problems it would occur in that time. How many of your Hummie hubs are coming back after 12 months, Bet you wont be telling us that.
will you wouldn’t have a gear and pulley setup with a one-to-one ratio. If you still have gearing reduction then it would be better for torque then Hub Motors
You do know power is provided from the battery…
BEST ELECTRIC SKATEBOARD MOTORS FOR SPEED & TORQUE | MOST POWERFUL DIRECT DRIVE MOTORS 2019
Energy provided by battery. Power by motors and esc
You need to be selling battery & esc with your hubs so you can make some legit claims.
Motors have a power rating. A higher rating (assuming it’s legit) is a more powerful motor. You’d need a battery and esc that can put out what the motor is capable of but still a motor can have a power rating of its own. Happens all the time. @Dedbny I haven’t had a return yet. Everyone but one person who bought them is on the forum and I’m hoping to hear any negative feedback.
I suppose what I’m actually curious about is why hub motors are less efficient, is it only because they have trouble cooling? If this is the case doesn’t a power rating for a hub motor have to reflect a hub motors cooling ability?
Generally, efficiency of a motor is proportional to the heat generated and a bunch of other factors. There is more emphasis on heat generated because urethane is a poor conductor of heat. Power rating of a motor is somewhat dependent of its cooling ability if you compare a 2000 W motor and a motor from a Tesla Models S P100D. Although these are two different motors, the construction of it factors more into the efficiency. If you were to build a frictionless less motor that generates no heat. The motor is limit by how much current it takes before it self destructs.
I’d be interested to see some data comparing hub motor vs satellite motor range for routes that are mostly flat vs routes that have a lot of hills. I love the simplicity of hub motors, but when you live in a city that is built mostly on hills, they just don’t really seem practical.
