Cost-Benefit Comparison: Lower Cost and Higher Power Electric Bike Motors

[Mike leroy]

This article investigates whether Neodymium motors have the potential to double peak torque at half the cost of traditional eBike samarium cobalt motors. Neodymium is about half the cost of traditional ebike Samarium Cobalt magnets. Neodymium magnets are also lighter. See this thread about the risk of insufficient glue used in some neodymium motors.

Repeat after me, "Neodymium". A tongue twister! NeoWhat? NeoNazi? NeoJumper (EasyMotion)? NeoDummy? NeoDada? No, articulate Swahili very sloooowly and deliberately. NeoDimwit? NeoFascist? Huh? NeoDone!

I give up, pronounce for my twisted tongue, Google. I have an ear ache from straining so hard.

Oh, you don't say. More accurately, you pronounce better than me!

Currie Tech uses neodymium magnets in some of their high torque motors, 42Nm nominal, 96Nm torque from 750W, 36V. Compare with 75oW, 40Nm nominal, 50Nm peak, Polaris Aapex. The iZip Express generates almost twice the peak torque, which is a huge improvement. My rule-of-thumb is 5Nm for each percent grade at my weight (175 pounds) at wobble speed (9mph). So, I expect the iZip Express could climb the steepest hills in my area (20% grade). I estimate the Aapex could only push me up the slightest hills (10% grade) at wooble speed.

1. MOTOR: Exclusive Currie Electro-Drive® 750W Hi-Torque DC Neodymium Magnet Motor
2. MOTOR SPECIFICATIONS: 96 Nm Peak Torque, 42 Nm Rated Torque, 750 Watts
3. BATTERY: EV Rated Rechargeable Lithium-ion Cells In Power Pack with Advanced Power Management System 36V20Ah 720Wh

The 4000W HPC motor weighs 15.9 lbs. The 6000W neodymium motor weighs 16.9 lbs. A 50% increase in power for an 8% weight increase, or one pound. The Sm-Co 3500W Revolution Sport weighs 79 pounds, which is only suitable for local commuting.

I would buy a 50 pound, geared, 1000W neodynymiun HPC Revolution, which would allow me to take the bike on Amtrak trips.

The 79 pound Revolution has a Sm-Co motor that is seven pounds heavier than the 1000W motor. The 36V, 26Ah battery for the 1000W motor only weighs 9.5 pounds. The 78V, 26Ah battery weighs 13.5 pounds. The 11 pound battery and motor difference would bring a 1000W HPC Revolution down to 68 pounds. Without the battery, a 1000W Revolution would weigh about 58 pounds. A new motor might even bring the weight close to 55 pounds. Very close to my goal!

I like many features about the $9000 HPC Revolution. I especially like the swingarm because the rear wheel weighs about 35 pounds, or about half of the total weight. Neodymium will cut the weight significantly .

Take a look at the 68 pound, neodymium-powered iZip express; 95Nm torque for $2800! In my mind, the iZip is a better deal, pound for pound.

In passing, each Toyota Prius contains 2.2 pounds of Neodymium magnets.

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I write articles in my spare time from the comfort of my iPad and bed. I will update this post as I learn about neodymium motors. Check back frequently. The content changes daily for the first week.

 

[Racingkyle]

My questions-
They have a geared and non geared striker motor. The non geared one is much higher power, so which one should I get?

Do either of the geared or non geared striker motors have neodium magnets?

Will the geared and non geared motors be able to go 45?

 

[Mike leroy]

Kyle,

My understanding is geared motors are OK under 1000 to 2000 watts. Over 2000 watts, geared motors are not recommended. I will find the reasons for you, as I do not recall them now.

To reach 45mph speeds, gearless.

I cannot find the exact info about motors with neodymium magnets. I only know the 5000+ watt motors also have that option. I believe the reason is higher voltage, e.g., 90V.

The striker motors are probably wound differently that the other two HPC motors. The same magnets are probably used in all three motors.

Suppose you want to buy two wheels for the same bike frame, which I plan to. You need to make sure the controller and battery can handle the same voltage for neodymium and traditional motors.

 

[Racingkyle]

Kyle,

My understanding is geared motors are OK under 1000 to 2000 watts. Over 2000 watts, geared motors are not recommended. I will find the reasons for you, as I do not recall them now.

To reach 45mph speeds, gearless.

I cannot find the exact info about motors with neodymium magnets. I only know the 5000+ watt motors also have that option. I believe the reason is higher voltage, e.g., 70V.

The striker motors are probably wound differently that the other two HPC motors. The same magnets are probably used in all three motors.

Suppose you want to buy two wheels for the same bike frame, which I plan to. You need to make sure the controller and battery can handle the same voltage for neodymium and traditional motors.

So I would defiantly go for a fearless striker hub motor for these reasons.

More torque for hills means it will accelerate faster, do you agree?

I need hill climbing ability.

I don't want low a low wattage motor.

How can we figure out which motors have neodymium magnets? Is there a difference? Can I choose which motor I can get with the revolution?

 

[Mike leroy]

So I would defiantly go for a fearless striker hub motor for these reasons.

More torque for hills means it will accelerate faster, do you agree?

I need hill climbing ability.

I don't want low a low wattage motor.

How can we figure out which motors have neodymium magnets? Is there a difference? Can I choose which motor I can get with the revolution?

Kyle,
The fastest motor is the Black Lightening, not the Striker. Unfortunately, the acceleration info is missing. Acceleration is generally correlated with voltage. So, you want the Striker with the highest voltage. The Stryker has higher torque, which is probably due to motor windings.

Yes, the HPC Revolution is modular, so you can configure the Revo to suit your tastes. Provided the controller and battery are compatible voltage, you should be able to swap wheels with different hub motors. At least, that is what I plan to do. I want two motors; a light, low-power and a second heavy, high-power version.

I think neodymium is no new that the info has not yet made it to the web site. I have a feeling the 90V system is required for neodymium motors. Only the 5000+ watt motors offer neodymium as an option, according to today's web page.

 

[Racingkyle]

Kyle,
The fastest motor is the Black Lightening, not the Striker. Unfortunately, the acceleration info is missing. Acceleration is generally correlated with voltage. So, you want the Striker with the highest voltage. The Stryker has higher torque, which is probably due to motor windings.

I believe the HPC Revolution is modular. Provided the controller and battery are compatible voltage, you should be able to swap wheels with different hub motors. At least, that is what I plan to do.

I think neodymium is no new that the info has not yet made it to the web site. I have a feeling the 90V system is required for neodymium motors. Only the 5000+ watt motors offer neodymium as an option, according to today's web page.

You are right and wrong. The acceleration isn't only dependent on voltage. It depends on how much power the magnets/weave have to move you. I'd imagine that the striker is fast but takes a while to get going. I wouldn't want to be switching wheels all the time, so I think I'll contact hpc.

 

[Mike leroy]

You are right and wrong. The acceleration isn't only dependent on voltage. It depends on how much power the magnets/weave have to move you. I'd imagine that the striker is fast but takes a while to get going. I wouldn't want to be switching wheels all the time, so I think I'll contact hpc.

If you look at the different motors, the power (watts) goes up with voltage. Watts = Volts x Amps.