50nm mid drive vs 50nm hub drive

mikecoin56

New Member
I am currently riding an Aventon Pace 500 which I am generally pleased with. A couple annoying features though have me now looking at a mid drive bike.

The Aventon is a 500 watt, 48 volt, 50 nm, 8 speed rear hub motor ebike that is capable of ascending every hill I've tried even with my 250 pound weight. Albeit sometimes slowly.

I dislike the abrupt on-off feel of the motor due to the cadence sensor and the inability to pedal constantly in PAS 1 without going 11-12 mph.

I also dislike that the assist doesn't start helping from a stop until a pedal revolution or so.

I do like the relaxed, upright riding style as I'm 63 with some health issues.


Looking at Trek mid-drive ebikes with the 2020 Bosch Active Line Plus motor and 50 nm torque (Verve+ 3).

Or a 2020 Specialized mid-drive ebike with Brose 1.2e motor and 50 nm torque (Como 3).

Would either of these two mid drives perform as well or better on hills as the Aventon?

Do I need to go to the Electra Path Go and it's Bosch Performance line motor with 65 nm torque?

Or the Specialized Como 4 with its Brose 1.3 motor and 75 nm torque?
 

Katysax

Active Member
I have the Specialized Como 4.0 and regularly use it to climb local mountain passes. It has power to spare. Recently my partner test rode the Como 3.0 and 4.0 and concluded that the difference in the motor was meaningful and worth the cost for the upgrade.
 

TMH

Well-Known Member
We can down to the conclusion that torque number is marketing hype.
I haven't read the referenced thread, but based on personal experience I don't agree with your conclusion. And that experience is based on a pretty apples-to-apples comparison - all mid-drives, similar wheel/tire sizes, similar bike weights, different motors from the same manufacturer, etc.
 

Timpo

Well-Known Member
I haven't read the referenced thread, but based on personal experience I don't agree with your conclusion. And that experience is based on a pretty apples-to-apples comparison - all mid-drives, similar wheel/tire sizes, similar bike weights, different motors from the same manufacturer, etc.
well what can I say, I'm speaking from experience too.

There's no way my ebike has more torque than my motorcycles.

50Nm? Seriously? I could be wrong, but I found it a bit unbelievable.
 
Last edited:

TMH

Well-Known Member
And... there is no way that your motorcycles are as light as your e-bike. Nor are the drive components on your motorcycle (wheels, tires, chain) nearly as light as those on your e-bike, so the torque of your motorcycle ICE is comparatively masked as compared to an e-bike. Plus electric motors make a lot more torque for their size as compared to ICE. Plus your motorcycle is not as dependent on having a high torque due to its huge (comparatively speaking) fuel tank as compared to an e-bike battery. yada yada

But what I actually said is that I don't agree with your conclusion that the torque numbers are only marketing hype. I can easily feel the difference between an e-bike which is marketed as having 60nm of torque, and one which is marketed as having 75nm of torque, both from the same manufacturer and in similar platforms. So whether or not the motors actually put out the specified torques is unknown to me, and is potentially marketing hype. But differences in motors marketed as having higher or lower torque, in my personal experience, are quite discernible and are more than just marketing hype. Maybe I just disagreed with the inaccurate blanket statement?
 

Timpo

Well-Known Member
And... there is no way that your motorcycles are as light as your e-bike. Nor are the drive components on your motorcycle (wheels, tires, chain) nearly as light as those on your e-bike, so the torque of your motorcycle ICE is comparatively masked as compared to an e-bike. Plus electric motors make a lot more torque for their size as compared to ICE. Plus your motorcycle is not as dependent on having a high torque due to its huge (comparatively speaking) fuel tank as compared to an e-bike battery. yada yada

But what I actually said is that I don't agree with your conclusion that the torque numbers are only marketing hype. I can easily feel the difference between an e-bike which is marketed as having 60nm of torque, and one which is marketed as having 75nm of torque, both from the same manufacturer and in similar platforms. So whether or not the motors actually put out the specified torques is unknown to me, and is potentially marketing hype. But differences in motors marketed as having higher or lower torque, in my personal experience, are quite discernible and are more than just marketing hype. Maybe I just disagreed with the inaccurate blanket statement?
That's exactly my point, motorcycles are a lot heavier.
Yet, with less torque, it goes faster and climb much better than ebikes.
On steep hill, ebikes with 50nm can barely climb without pedaling, yet motorcycle with 50nm of torque can climb and rev pretty fast on steep hill.

Also, if you look at the discussion on other thread, electric motorcycles are creating about the same (or less) torque than small ebike motors.
So those little Bafang or Bosch mid drive are creating more torque than much bigger motorcycle mid drive electric motors.

Yet motorcycle motors can carry a lot heavier loads.
 

TMH

Well-Known Member
I'm afraid that your analogy of a motorcycle to an e-bike is too much of an oversimplification to be accurate or to make your argument. Torque (a measure of rotational force) is only a single factor in determining a vehicle's functionality. Higher torque allows higher work (a measure of force over a distance). Power is a measure of how quickly work can be performed.

To differentiate between e-bikes and ICE motorcycles:

Torque may be similar, but
A motorcycle can work longer (apply the motor's torque for a longer period of time) since its energy supply (fuel in its tank) is much larger than the energy available in an e-bike battery (for example 1 gallon of gasoline has 124,000 Btu of energy content while a 1Kwh battery has 3,413 Btu of energy content); and
Power of a ICE motorcycle engine is so significantly higher than that of an e-bike (a 500 watt e-bike generates less than 1 HP, but your motorcycle generates 50, 80, 150HP?)

So arguing that an e-bike can't have anywhere near the same torque as your motorcycle (and therefore it is all just marketing hype) is inaccurate as you have only addressed a single measured factor in the entire system, and not the system as a whole.
 

Timpo

Well-Known Member
I'm afraid that your analogy of a motorcycle to an e-bike is too much of an oversimplification to be accurate or to make your argument. Torque (a measure of rotational force) is only a single factor in determining a vehicle's functionality. Higher torque allows higher work (a measure of force over a distance). Power is a measure of how quickly work can be performed.

To differentiate between e-bikes and ICE motorcycles:

Torque may be similar, but
A motorcycle can work longer (apply the motor's torque for a longer period of time) since its energy supply (fuel in its tank) is much larger than the energy available in an e-bike battery (for example 1 gallon of gasoline has 124,000 Btu of energy content while a 1Kwh battery has 3,413 Btu of energy content); and
Power of a ICE motorcycle engine is so significantly higher than that of an e-bike (a 500 watt e-bike generates less than 1 HP, but your motorcycle generates 50, 80, 150HP?)

So arguing that an e-bike can't have anywhere near the same torque as your motorcycle (and therefore it is all just marketing hype) is inaccurate as you have only addressed a single measured factor in the entire system, and not the system as a whole.
sorry for my ignorance, but what's ICE motorcycle?😑

Anyways, that's my point too, torque doesn't mean anything. (or torque doesn't mean everything)
If that's the case, you can't say 50nm ebike is weaker than 150nm ebike for hill climbing and hauling things.

So, maybe as you suggested, maybe horsepower is what counts.

Simply put, 400 lb motorcycle with mere 50nm of torque is a lot faster and stronger than 60 lb ebikes with 160nm of torque.
 

Scott Adams

Active Member
this is a bit of a thorny issue and manufacturers don't help when they release non-standardized numbers which don't include the torque value along the relevant range of RPMs from zero to no-load (top speed) at a given voltage

no doubt that marketing plays a role in what torque value is assigned to a motor as well

I'm not even sure if the torques are all measured at the shaft of the motor and without having been through any gears, or at what RPM

a motor with half as much torque, but produced at four times the RPM will be twice as powerful and so on

power = torque x RPM

work (or energy) = torque x degrees of rotation

gears function to trade torque for RPM, every time one goes up, the other goes down proportionally, so you can play with torque to no end using gears

in a better world, an independent tester (perhaps EBR if it weren't so expensive to do) would generate test numbers on a dynamometer, one from BionX was for sale after the recent bankruptcy...

what can be measured and recorded more readily, but with a bit of work and equipment, is the watt draw of the motor during operation of your bike

working backwards from the watts to the torque can then be done if you make some fairly safe assumptions about the efficiency curve of the motor and what gear your bike was in if it is a mid-drive, and also what gears are in the motor

as you guys pointed out, the hub motor can only hit it's efficiency sweet spot at a narrow range of RPM, while the mid-drive is decoupled from the wheel by the gears and can run closer to it's desired RPMs at a wide range of wheel speeds

if enough users ask for the information we need, one day we might get it!
 
Last edited:

EMGX

Well-Known Member
Personally I would stick with 70nm or greater, assuming that torque value ratings are equivalent across different brands, but I live in a very hilly area. I'm happy with my Yamaha PW-SE mid drive powered gravel bike which is rated at 70nm and thankful that it doesn't have less power when climbing steep roads. I don't use the "high" setting very much but I wouldn't want to be without the power that it provides for some situations. Even with that degree of torque I once stalled the motor pedaling hard when I turned on to a very steep short hill in too high of a gear. This with a very light (for an ebike) 40# bike, more torque might be a good thing with most bikes I see weighing 60# and up. Power delivery seems very natural and smooth to me.
 

TMH

Well-Known Member
ICE=internal combustion engine

Torque is a very meaningful measure of as it can show a comparative difference between 2 motors in how much work (for example, climbing assistance) one might be able to provide as compared to the other. But it is not the only important factor in an overall system. This addresses my point to your original claim to a new Forum member that " torque number is marketing hype ". This is an incorrect statement to make to someone who is attempting to learn more details about different e-bikes. So your statement above "(or torque doesn't mean everything)" is highly accurate.

My claim, and I stick with it, is that my experience has shown me that in 2 different e-bikes, of similar weight, drive type, tire size, etc. (note I am not comparing to motorcycles since I am comparing motors in similar systems) with differing motor torque specifications, I can tell the motor with the higher torque based on hill climbing performance. Higher torque is an important variable to consider. It is not just marketing hype.
 

EMGX

Well-Known Member
Some of the hills I've done on this bike which I would not want to ride (or could not ride) with a regular pedal bike.

20191213_122336.jpg



20200224_114231.jpg


20200215_114027.jpg
 

Timpo

Well-Known Member
ICE=internal combustion engine

Torque is a very meaningful measure of as it can show a comparative difference between 2 motors in how much work (for example, climbing assistance) one might be able to provide as compared to the other. But it is not the only important factor in an overall system. This addresses my point to your original claim to a new Forum member that " torque number is marketing hype ". This is an incorrect statement to make to someone who is attempting to learn more details about different e-bikes. So your statement above "(or torque doesn't mean everything)" is highly accurate.

My claim, and I stick with it, is that my experience has shown me that in 2 different e-bikes, of similar weight, drive type, tire size, etc. (note I am not comparing to motorcycles since I am comparing motors in similar systems) with differing motor torque specifications, I can tell the motor with the higher torque based on hill climbing performance. Higher torque is an important variable to consider. It is not just marketing hype.
Okay, I was not talking about internal combustion engine specifically.

I know you said you didn't read the forum, but I was comparing electric motorcycle.

Somehow, ebike can generate equal (or more) torque than electric motorcycle motors.
 

Timpo

Well-Known Member
Personally I would stick with 70nm or greater, assuming that torque value ratings are equivalent across different brands, but I live in a very hilly area. I'm happy with my Yamaha PW-SE mid drive powered gravel bike which is rated at 70nm and thankful that it doesn't have less power when climbing steep roads. I don't use the "high" setting very much but I wouldn't want to be without the power that it provides for some situations. Even with that degree of torque I once stalled the motor pedaling hard when I turned on to a very steep short hill in too high of a gear. This with a very light (for an ebike) 40# bike, more torque might be a good thing with most bikes I see weighing 60# and up. Power delivery seems very natural and smooth to me.
What does 70nm mean though?

That's as much torque as Harley Davison electric motorcycle.

It has what? Nearly 600 lbs and still pull harder and goes a lot faster on steep hill.

I know ebikes with 70nm torque are barely moving (if throttle only) on steep hill.. or moving very slowly
 

EMGX

Well-Known Member
What does 70nm mean though?

That's as much torque as Harley Davison electric motorcycle.

It has what? Nearly 600 lbs and still pull harder and goes a lot faster on steep hill.

I know ebikes with 70nm torque are barely moving (if throttle only) on steep hill.. or moving very slowly


What it means to me (based on experience with this bike) is that it is enough, but I wouldn't want less. I'm not concerned about comparing it to a motorcycle or car but if the numbers are equivalent across brands of ebike motors it seems to me to be a useful measure for comparison of similar bicycles.
 

Timpo

Well-Known Member
What it means to me (based on experience with this bike) is that it is enough, but I wouldn't want less. I'm not concerned about comparing it to a motorcycle or car but if the numbers are equivalent across brands of ebike motors it seems to me to be a useful measure for comparison of similar bicycles.
Ok so what you're saying is that Bosch 75Nm "might" be just as powerful or torquey as Bafang 160Nm motor?
 

EMGX

Well-Known Member
Ok so what you're saying is that Bosch 75Nm "might" be just as powerful or torquey as Bafang 160Nm motor?


Not at all. If the torque ratings are comparable across brands I would expect that a 160nm motor would deliver approximately twice the assistance than one with 75nm would at the same rpm.
 

Timpo

Well-Known Member
Not at all. If the torque ratings are comparable across brands I would expect that a 160nm motor would deliver approximately twice the assistance than one with 75nm would at the same rpm.
Okay, but it sounds like you're being a bit subjective in terms of "comparable" across the brand.

What bothers me the most, is that, when it comes to engineering, it has to be logical, objective and scientific.

The torque rating should not differ by whatever marketing plan they have.
The little tiny ebike motor can apparently create as much or MORE torque than a much bigger motorcycle electric motor.

These are scientific numbers. They should not be differing between brands to brand.

If Brand A claims the bike weighs 55 lbs, and Brand B claims the bike is 60 lbs, the scientific number dos not change between brands.
"Oh, but in reality, the Brand A actually weighs heavier than Brand B's 60 lb bike, it's just a marketing hype"
It wouldn't make sense.
 
Last edited:

AHicks

Well-Known Member
Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
Timpo, let's keep it simple. Let's assume electric motorcycles, and motorcycles in general, are rated differently than an e-bike. If you would like to figure out/discuss what that difference is, maybe start a new string on that topic?

I would agree that the advertised torque (nm) rating on bikes, all else being equal, is a big help when comparing one bike to another - especially when it comes to newbies trying to figure out what's going on.