Motor power and acceleration

[Patton250]

Guys I’m sure this has been discussed ad nauseam and if you want to point me to specific threads that’s fine. The three main wheels I own and use right now are KS18XL this has the new 2200W motor, KS16X this also has the 2200W motor and the GW Nik+ and this has a 2000W motor. I know it’s blasphemy around here but I don’t really care about battery so let’s stick this discussion to motor power unless of course battery affects that.  I know that some of you guys are extremely smart and know these things inside and out so I’ve come to the right place to ask these questions. Of these three wheels I think the 18XL is the zippiest or has the best acceleration with the KS16X and GW Nik+ pretty close to each other. Does the motor power mean different things for different brands? Like the new MSX Pro has a 2500W motor. Does that mean this will be the fastest accelerating wheel on the market right now? Why is IM only putting a 2000W motor in the new V11? That’s the same motor they have in their V10 right? If that’s true can we expect the same type of accelerations and speeds from their newest wheel? Same with the KS S18. This has the same motor as the 16 X only now we have a larger wheel so I expect the S18 to be more sluggish and slower than the 16 X. Is this your assessments as well? In other words looking at these two new wheels with suspensions I don’t see how other than having the suspensions they will be any more spectacular than what’s already in circulation and in fact perhaps not as good at acceleration and speed. It seems the only new wheel coming out that will have more power and therefore more acceleration and speed is the new wheel that does not have suspension i.e. the GW MSX Pro. And if that’s not significantly better than the Nik+ or 16X as far as speed and acceleration goes then there’s really nothing new to buy this year except suspension on slower wheels. Does all this sound about right?

[Sai]

I guess they are aiming more for the mass market in terms of safety and comfortability? Ie the newest cars are not always the fastest. 

[Patton250]

12 minutes ago, Sai said:

I guess they are aiming more for the mass market in terms of safety and comfortability? Ie the newest cars are not always the fastest. 

I probably should have been more specific so I apologize. I don’t really care about top end speed. I’m not going to go 40 mph. But it is fun getting from 0 to 25 mph faster. Which of these motors combined with the new wheel will accomplish that the best? I guess that was the question.

[tudordewolf]

49 minutes ago, Patton250 said:

I probably should have been more specific so I apologize. I don’t really care about top end speed. I’m not going to go 40 mph. But it is fun getting from 0 to 25 mph faster. Which of these motors combined with the new wheel will accomplish that the best? I guess that was the question.

If you can't out-torque a wheel with your legs, you're not using its full power nor will more watts (or even just more torque) make you accelerate faster; it's more about how far the software lets you lean before it "throttles up" to bring the wheel back under you. Max wattage isn't acheived until you're at a sweet spot of high RPM's and high current draw.

You'll accelerate in any direction at a rate pretty much proportional to your degree of lean; but you have to "fight" the wheel to lean off of it, so it's more about the wheel's software and your ability to grip it with your legs and "force" it forward. If you're not over-leaning the wheel, then you're not maxing out its torque and therefore power. Extra watts is extra safety at high speed, but larger axle diameter (for thicker motor wires to carry more current ) and lower Kv motors (MSX Pro probably has the lowest with 2500 watts and a lower top speed than the MSX ) will offer you the most in the low-end.

 

Kv is basically how a motor is "geared", whether for RPM's or torque, (it is a little more complicated than that but the functional effect is, low kv = high torque less rpm's, high kv = low torque but more rpm's) It would be really cool for manufactureres to publish that figure about their motors, but I imagine it would confuse most people more than help, especially as a lower rating is often "better"

Edited April 26, 2020 by tudordewolf

[UniVehje]

42 minutes ago, Patton250 said:

I don’t really care about battery so let’s stick this discussion to motor power unless of course battery affects that

The motor does not produce any power, the batteries do that. The board regulates it and the motor is there to transfer it to rotation. The rating does not mean how powerful it is, just how much power you can put through it continuously without overheating it. Don’t think too much about that number. The peak power is much more in every wheel and almost never will you need more than 2000W for long time. 
 

48 minutes ago, Patton250 said:

Why is IM only putting a 2000W motor in the new V11? That’s the same motor they have in their V10 right?

Nope, not the same. It’s 2x bigger and 50% More power. A new in-house design and likely larger magnets. Just the continuous rating is the same.

And motor rating has nothing  to do with acceleration or zippy feeling. You can even have the same motor in different versions, you can get more rpm but with less torque or vice versa. But even that doesn’t affect zippyness that much. it’s mostly about wheel size and firmware. You will not get answers to your question before testing and even then it will be anecdotal as acceleration is a matter of how much you dare to lean. 

 

 

[Patton250]

11 minutes ago, UniVehje said:

The motor does not produce any power, the batteries do that. The board regulates it and the motor is there to transfer it to rotation. The rating does not mean how powerful it is, just how much power you can put through it continuously without overheating it. Don’t think too much about that number. The peak power is much more in every wheel and almost never will you need more than 2000W for long time. 
 

Nope, not the same. It’s 2x bigger and 50% More power. A new in-house design and likely larger magnets. Just the continuous rating is the same.

And motor rating has nothing  to do with acceleration or zippy feeling. You can even have the same motor in different versions, you can get more rpm but with less torque or vice versa. But even that doesn’t affect zippyness that much. it’s mostly about wheel size and firmware. You will not get answers to your question before testing and even then it will be anecdotal as acceleration is a matter of how much you dare to lean. 

 

 

Well this was an interesting post and I appreciate you taking the time. Basically you’re saying the answers to my questions are we don’t know yet. :-)

It does seem as though you believe these newer motors are more advanced and therefore have at least the possibility of being quicker to reach TopSpeed.

15 minutes ago, tudordewolf said:

If you can't out-torque a wheel with your legs, you're not using its full power nor will more watts (or even just more torque) make you accelerate faster; it's more about how far the software lets you lean before it "throttles up" to bring the wheel back under you. Max wattage isn't acheived until you're at a sweet spot of high RPM's and high current draw.

You'll accelerate in any direction at a rate pretty much proportional to your degree of lean; but you have to "fight" the wheel to lean off of it, so it's more about the wheel's software and your ability to grip it with your legs and "force" it forward. If you're not over-leaning the wheel, then you're not maxing out its torque and therefore power. Extra watts is extra safety at high speed, but larger axle diameter (for thicker motor wires to carry more current ) and lower Kv motors (MSX Pro probably has the lowest with 2500 watts and a lower top speed than the MSX ) will offer you the most in the low-end.

 

Kv is _basically_ how a motor is "geared", whether for RPM's or torque, (it is a little more complicated than that but the functional effect is, low kv = high torque less rpm's, high kv = low torque but more rpm's) It would be really cool for manufactureres to publish that figure about their motors, but I imagine it would confuse most people more than help, especially as a lower rating is often "better"

Any chance you can break that all down for dumb people that went to public school? lol :-)

[UniVehje]

17 minutes ago, Patton250 said:

It does seem as though you believe these newer motors are more advanced and therefore have at least the possibility of being quicker to reach TopSpeed.

Not really. I do believe the new motors are more advanced, but only slightly. There's not much they can do at today's technology. It's just magnets and copper coils. 

But motor (and especially the continuous rating)  is not the bottle neck for acceleration. I think you are thinking this too much like ICE cars. On cars you can compare the engine specs and see how it affects acceleration. The more horse power or watts it produces the faster you can accelerate if you have the same torque and gearing setup. On EUCs the motor is not like that, you have to look at the whole system. And, again, the motor is still not the bottle neck. 

To use car analogy: Let's say we compare 100 hp Toyota Corolla and 250 hp sports car. But on the Corolla you use first gear and on the sports car you use 3rd gear. I'm sure the corolla would get faster to 25 mph despite the smaller engine. Or you could compare them on the same gear but you could push the pedal on the sports car on 1/4 of the way. Same effect, the one pushed all the way down would win. 

On an EUC the motor, or the whole system from batteries to the motor through mosfets, can produce something like 4000-6000W peak power. But the bottle neck is gearing and leaning. These wheels don't really have gears or you could say they have only one gear. It's a direct drive so the wheel size is the gear. You could say that a bigger wheel is like using a higher gear. Plus you have to lean more on a bigger wheel, which brings us to the second bottle neck: throttle. The only purpose of the wheel is to keep you up, movement is a by product. It only wants to stay under you. If you shift your center of gravity forward, it has to move forward to stay under you. 

So let's say you have a 800W and 2500W motors and both are on same size tire. If you shift your center of gravity 10cm, both would accelerate the same. If you want the motor power to do anything, you have to lean more. There's no full throttle setting on EUCs. They give as much peak power as needed to catch your leaning until they run out of it. And when they run out of it, it's the battery voltage sagging that becomes the bottle neck, still not the motor rating. I'm not saying the motor has no effect, just that for your question there are many other things affecting it that you can almost forget the motor. 

The reason wheel size and firmware have bigger effects is that a good firmware can help you lean better (pedal softness and reactivity) and on smaller wheels you need to lean less to feel zippy. Plus the motor is working inside a smaller "gear" and thus has easier time accelerating. Remember, if you didn't face plant you could have accelerated even faster. You didn't go full throttle if the wheel could catch you. Get some pads to help you lean more and you don't need bigger motor. 

[tudordewolf]

46 minutes ago, Patton250 said:

Any chance you can break that all down for dumb people that went to public school? lol :-)

On a lower-power wheel, if I lunged forward with everything I had, I'd exceed its max torque and stumble forward off of it. On a larger wheel like an MS3+, I physically can't get it to do that. It makes a subtle sci-fi "bbwoOOO" sound and gets me to 20mph in just under 4 seconds, from a standstill. More torque or a higher wattage motor wouldn't get me there faster, because I'm the limiting factor.

You ideally want that to always be the case, or else you're in an over-lean situation and crashing, so the latest generation wheels tend to have pretty substantial torque overheads. This means the max torque/acceleration you experience is based on how much you are able to derive from the wheel. 

It is because of this weird equilibrium-based relationship between you and the wheel. It's not like a car where you can arbitrarily apply full throttle, it's like the gas pedal pushes back based on how hard the engine is working; you have to "push" the unicycle behind you to make it push you forward, and your ability to accelerate is based on how hard of a leg-press you can sustain against your wheel.

Watts consumed is proportional to rpms x torque. You won't hit max watts until you're relatively high in the rpm range, because the torque is going to be fairly constant throughout.

The manufacturer wattage numbers are describing the max it can reach, not the flat-out power output of the motor. This max is wherever the available torque falls below an acceptable safety margin, which doesn't happen until the wheel's top speed. 

It's very much like the power curve of an internal combustion engine; a 500hp engine can't produce 500hp at idle or even right after you hit the gas, that's the peak it reaches at a certain rpm.
 

Edited April 26, 2020 by tudordewolf

[Patton250]

1 hour ago, tudordewolf said:

On a lower-power wheel, if I lunged forward with everything I had, I'd exceed its max torque and stumble forward off of it. On a larger wheel like an MS3+, I physically can't get it to do that. It makes a subtle sci-fi "bbwoOOO" sound and gets me to 20mph in just under 4 seconds, from a standstill. More torque or a higher wattage motor wouldn't get me there faster, because I'm the limiting factor.

You ideally want that to always be the case, or else you're in an over-lean situation and crashing, so the latest generation wheels tend to have pretty substantial torque overheads. This means the max torque/acceleration you experience is based on how much you are able to derive from the wheel. 

It is because of this weird equilibrium-based relationship between you and the wheel. It's not like a car where you can arbitrarily apply full throttle, it's like the gas pedal pushes back based on how hard the engine is working; you have to "push" the unicycle behind you to make it push you forward, and your ability to accelerate is based on how hard of a leg-press you can sustain against your wheel.

Watts consumed is proportional to rpms x torque. You won't hit max watts until you're relatively high in the rpm range, because the torque is going to be fairly constant throughout.

The manufacturer wattage numbers are describing the max it can reach, not the flat-out power output of the motor. This max is wherever the available torque falls below an acceptable safety margin, which doesn't happen until the wheel's top speed. 

It's very much like the power curve of an internal combustion engine; a 500hp engine can't produce 500hp at idle or even right after you hit the gas, that's the peak it reaches at a certain rpm.
 

Thank you so much. I’m understanding this better. I guess what I’m hoping for that as 150 pound man I wish I didn’t have to lean and push so hard to make these wheels go faster. I wish there was a way to adjust that better. That’s why I’ve never been able to get my Nik+ to full speed. Once I hit 33 mph I just don’t have the balls at that speed to lean 45° and push all my strength down on the pedal to go faster. I don’t have to do that to get to 30 mph why do I have to do it to go faster?

1 hour ago, UniVehje said:

Not really. I do believe the new motors are more advanced, but only slightly. There's not much they can do at today's technology. It's just magnets and copper coils. 

But motor (and especially the continuous rating)  is not the bottle neck for acceleration. I think you are thinking this too much like ICE cars. On cars you can compare the engine specs and see how it affects acceleration. The more horse power or watts it produces the faster you can accelerate if you have the same torque and gearing setup. On EUCs the motor is not like that, you have to look at the whole system. And, again, the motor is still not the bottle neck. 

To use car analogy: Let's say we compare 100 hp Toyota Corolla and 250 hp sports car. But on the Corolla you use first gear and on the sports car you use 3rd gear. I'm sure the corolla would get faster to 25 mph despite the smaller engine. Or you could compare them on the same gear but you could push the pedal on the sports car on 1/4 of the way. Same effect, the one pushed all the way down would win. 

On an EUC the motor, or the whole system from batteries to the motor through mosfets, can produce something like 4000-6000W peak power. But the bottle neck is gearing and leaning. These wheels don't really have gears or you could say they have only one gear. It's a direct drive so the wheel size is the gear. You could say that a bigger wheel is like using a higher gear. Plus you have to lean more on a bigger wheel, which brings us to the second bottle neck: throttle. The only purpose of the wheel is to keep you up, movement is a by product. It only wants to stay under you. If you shift your center of gravity forward, it has to move forward to stay under you. 

So let's say you have a 800W and 2500W motors and both are on same size tire. If you shift your center of gravity 10cm, both would accelerate the same. If you want the motor power to do anything, you have to lean more. There's no full throttle setting on EUCs. They give as much peak power as needed to catch your leaning until they run out of it. And when they run out of it, it's the battery voltage sagging that becomes the bottle neck, still not the motor rating. I'm not saying the motor has no effect, just that for your question there are many other things affecting it that you can almost forget the motor. 

The reason wheel size and firmware have bigger effects is that a good firmware can help you lean better (pedal softness and reactivity) and on smaller wheels you need to lean less to feel zippy. Plus the motor is working inside a smaller "gear" and thus has easier time accelerating. Remember, if you didn't face plant you could have accelerated even faster. You didn't go full throttle if the wheel could catch you. Get some pads to help you lean more and you don't need bigger motor. 

Brother I really like how you broke that down and I have a much better understanding of how these things work. Thank you so much for taking the time to write that out.

[RetroThruster]

I share the same sentiments, I'm seeing around 1800 watts climbing my long steep driveway on my 16x traveling at just above walking speed (weigh 210 lbs) with what I feel is much effort, I'm hoping for a marginal increase in speed with my incoming MSP.

Edited April 26, 2020 by RetroThruster

[UniVehje]

55 minutes ago, RetroThruster said:

I share the same sentiments, I'm seeing around 1800 watts climbing my long steep driveway on my 16x traveling at just above walking speed (weigh 210 lbs) with what I feel is much effort, I'm hoping for a marginal increase in speed with my incoming MSP.

there’s a good explanation on that linked video by @RockyTop on why the MSP might not feel any easier. The whole thread is a good read. Get an MCM5 if you want to go up easier. Powerpads help with easier leaning also. 

 

Edited April 26, 2020 by UniVehje

[RetroThruster]

43 minutes ago, UniVehje said:

there’s a good explanation on that linked video by @RockyTop on why the MSP might not feel any easier. The whole thread is a good read. Get an MCM5 if you want to go up easier. Powerpads help with easier leaning also. 

 

I'm just wondering how much faster the wheel could go even with power pads, if I'm at 1800 watts now, how much more speed will I have at the full 2200?  I've seen that btw, its' a good description.  Maybe a 14" wheel is in my future, just not a fan of that 2.125" tire on the MCM5 and don't want to have to modify it to a larger one.

Sorry to the OP for hi-jacking this thread, I'll put the brakes on here.

Edited April 26, 2020 by RetroThruster

[UniVehje]

12 minutes ago, RetroThruster said:

I'm just wondering how much faster the wheel could go even with power pads, if I'm at 1800 watts now, how much more speed will I have at the full 2200?

Try and see. If you lean more it will have to go faster to get under you. It wont stop at 2200w but if you go for too long it will probably alert before melting. You can get momentarily up to 6000w. Remember to wear protection when experimenting with the wheel’s capabilities. If you don’t learn to lean better a higher rated motor will not help you. It’s still a matter of skill more than motor power. Try standing more forward on the pedals, squeeze the wheel and throw your hands forward. Bend on the knees rather that Michael Jackson pose. Have fun practicing! 😎

[Patton250]

22 minutes ago, RetroThruster said:

I'm just wondering how much faster the wheel could go even with power pads, if I'm at 1800 watts now, how much more speed will I have at the full 2200?  I've seen that btw, its' a good description.  Maybe a 14" wheel is in my future, just not a fan of that 2.125" tire on the MCM5 and don't want to have to modify it to a larger one.

Sorry to the OP for hi-jacking this thread, I'll put the brakes on here.

No keep asking. I’m hoping this thread is going to help me decide which of these 3 new wheels to buy first.

[Patton250]

33 minutes ago, RetroThruster said:

I'm just wondering how much faster the wheel could go even with power pads, if I'm at 1800 watts now, how much more speed will I have at the full 2200?  I've seen that btw, its' a good description.  Maybe a 14" wheel is in my future, just not a fan of that 2.125" tire on the MCM5 and don't want to have to modify it to a larger one.

Sorry to the OP for hi-jacking this thread, I'll put the brakes on here.

I never noticed it was harder to get a larger wheel up a hill. I’ve never experienced that at all. Of course I’m only got to play with hills a few times since I live in Florida and everything is flat here but I have had the chance to go up some pretty steep hills.