1000w vs 1500w hub motor

[jr81212]

I have several builds experience. One 750w mid motor and several 1000w hub motors. I am generally satisfied with the performance of both Voilamart and Viribus as well as some unbranded kits I've used. I am considering a 1500w watt kit for my next project. Is it worth it? I have a battery that should be adequate, Hailong 48v, 20ah. I use the bike on a mixture of mountain gravel and two track. I am replacing a 1000w unbranded motor that died on me as I was flogging it up a very steep jeep trail. TYIA

 

[bananu7]

Were those geared or DD? A 1500W motor will typically be a DD motor, which has various funny implications going both into positives and negatives. That's likely going to be a bigger change than the rated power output.

 

[neptronix]

What you actually want is a motor that can handle more torque.

The smaller the wheel, the more torque.
The larger diameter the hub motor, the more torque.
This indicates to me that the ideal hub motor for you is probably a RH212 from ebikes.ca because it handles the low RPM situations better than most DD hubs since it has a larger diameter and more poles.

That motor would be 1-2lbs lighter than a regular 1500w motor, but still have higher low RPM torque which you need.
Whereas a regular 1500w motor would be way better at street duty because it can produce more torque in the mid to high range.

The other option of course is a mid drive, which is better for offroad duties with lots of variable grades..

 

[jr81212]

Were those geared or DD? A 1500W motor will typically be a DD motor, which has various funny implications going both into positives and negatives. That's likely going to be a bigger change than the rated power output.

It was a Direct Drive 1000w that failed.

 

[E-HP]

I have several builds experience. One 750w mid motor and several 1000w hub motors. I am generally satisfied with the performance of both Voilamart and Viribus as well as some unbranded kits I've used. I am considering a 1500w watt kit for my next project. Is it worth it? I have a battery that should be adequate, Hailong 48v, 20ah. I use the bike on a mixture of mountain gravel and two track. I am replacing a 1000w unbranded motor that died on me as I was flogging it up a very steep jeep trail. TYIA

If you're sticking with the same battery and voltage, the swap to a 1500W motor will only provide marginal performance benefits, mainly due to the higher power rating, which will allow it to withstand more heat when climbing. I'm assuming you're using Statorade if you're climbing steep hills with a direct drive motor. You should use a temp sensor if you're climbing so you aren't crossing your fingers and doing in blind.

Swapping to the RH212 would be an upgrade, but even then, sticking with the same voltage (and I assume current/controller) only provides marginal torque increases, mainly in the lower end.


Going to a higher voltage using the same motor, will provide a pretty significant torque advantage across the entire speed range.

 

[jr81212]

Th

If you're sticking with the same battery and voltage, the swap to a 1500W motor will only provide marginal performance benefits, mainly due to the higher power rating, which will allow it to withstand more heat when climbing. I'm assuming you're using Statorade if you're climbing steep hills with a direct drive motor. You should use a temp sensor if you're climbing so you aren't crossing your fingers and doing in blind.

Swapping to the RH212 would be an upgrade, but even then, sticking with the same voltage (and I assume current/controller) only provides marginal torque increases, mainly in the lower end.
View attachment 371264

Going to a higher voltage using the same motor, will provide a pretty significant torque advantage across the entire speed range.
View attachment 371265

Thank you! Very helpful!

 

[jr81212]

I

If you're sticking with the same battery and voltage, the swap to a 1500W motor will only provide marginal performance benefits, mainly due to the higher power rating, which will allow it to withstand more heat when climbing. I'm assuming you're using Statorade if you're climbing steep hills with a direct drive motor. You should use a temp sensor if you're climbing so you aren't crossing your fingers and doing in blind.

Swapping to the RH212 would be an upgrade, but even then, sticking with the same voltage (and I assume current/controller) only provides marginal torque increases, mainly in the lower end.
View attachment 371264

Going to a higher voltage using the same motor, will provide a pretty significant torque advantage across the entire speed range.
View attachment 371265

I am not familiar with a "statorade". As for temperature sensor, I only touch the controller an output wires to check for heat. I'd be interested in temperature sensor ideas. Thx

 

[neptronix]

Here's an example of what i mean about the dimensions of the motors mattering.



When you start climbing something.. the efficiency situation on the leafbike 1.5k versus rh212 flips.. the slower motor is not only going a little faster, but producing less heat while it's at it..



And as you can see, from a stall the slower motor is making a bit more torque per amp instead of more heat.

.. that's why i say this would be the best motor for off roading or hill climbing. The watt rating on the RH212 is a little deceptive.

And the smaller the wheel, the better, if you have a 29er, i'd downgrade to a 27.5" rear, using a slightly bigger tire at most. Notice i used a 26"?

Here's that same test with a 29".. notice that we go from overheating in 6.7 minutes to 4 minutes..

 

[E-HP]

I am not familiar with a "statorade". As for temperature sensor, I only touch the controller an output wires to check for heat. I'd be interested in temperature sensor ideas. Thx

The problem with hub motors is getting the heat out of the stator. Geared motors have no mechanism to do that, unless you fill them will oil. Direct drive motors with statorade provide a path for the heat to exit the motor, by bridging the gap between the stators and the magnets that are glued to the motor case. It makes a huge different when climbing steep hills and how long you can climb before melting the motor. You only need 10 ml max in most direct drive motors.

Statorade - Grin Products - Product Info

Statorade is a specially formulated ferrofluid that improves the thermal performance of direct drive hub motors. Just a small amount added to the motor magnets can double the thermal conductivity of the core, allowing the hubs to be driven harder and longer before risk of overheating.

ebikes.ca

Without it, you can touch a motor that's melting down inside, while the motor case may only feel lukewarm, and by the time the motor feels hot, it's cooked.

 

[neptronix]

Yeah statorade will about double the heat shedding capability of any motor.

You may or may not need it with a motor and wheel setup that's optimized for your conditions, versus what you had before.

 

[E-HP]

.Some of the motors modeled in the Grin Simulator have a few options. Stock motor, motor with Statorade, and motor with Statorade and hubsinks. Here's a standard wind 9C motor with and without Statorade, climbing a 6% grade. The motor without Statorade melts in 11 minutes, and the one with Statorade can just keep going, with a final temp of .>250C vs 123C. I don't like running over 100C, but the cooled motor should climb a long while before getting to 100C.

Motor Simulator - Tools

Our ebike motor simulator allows you to easily simulate the different performance characteristics of different ebike setups - with a wide selection of hub motors modeled, and the ability to add custom batteries and controllers and set a wide variety of vehicle parameters you'll be able to see...

ebikes.ca

11 minutes

 

[slaphappygamer]

Here's an example of what i mean about the dimensions of the motors mattering.

View attachment 371274

When you start climbing something.. the efficiency situation on the leafbike 1.5k versus rh212 flips.. the slower motor is not only going a little faster, but producing less heat while it's at it..

View attachment 371267

And as you can see, from a stall the slower motor is making a bit more torque per amp instead of more heat

.. that's why i say this would be the best motor for off roading or hill climbing. The watt rating on the RH212 is a little deceptive.

And the smaller the wheel, the better, if you have a 29er, i'd downgrade to a 27.5" rear, using a slightly bigger tire at most. Notice i used a 26"?

Here's that same test with a 29".. notice that we go from overheating in 5.7 minutes to 4 minutes..

View attachment 371273

Hey dude, was the last graph supposed to have the 29” tire? I don’t see that option was chosen.

Every time I look at the RH212, I want it. If I ever build a bike (or remove/burn my Shengyi) I’ll use this motor. I’d be traversing similar terrain to the OP and would definitely opt for statorade.

Also, the RH212 has a temp sensor built in. It’s very convenient to see the motor temp and the differences when ambient temp, or terrain, changes. I don’t stare at my temp, but I do note the temp a different points on my commute. Now I know the taxing areas of my commute and know when to back off the assist. Luckily though, I don’t really need to since I’m not trying to win a race.

 

[neptronix]

Hey dude, was the last graph supposed to have the 29” tire? I don’t see that option was chosen.

Fixed

Every time I look at the RH212, I want it. If I ever build a bike (or remove/burn my Shengyi) I’ll use this motor. I’d be traversing similar terrain to the OP and would definitely opt for statorade.

Also, the RH212 has a temp sensor built in. It’s very convenient to see the motor temp and the differences when ambient temp, or terrain, changes. I don’t stare at my temp, but I do note the temp a different points on my commute. Now I know the taxing areas of my commute and know when to back off the assist. Luckily though, I don’t really need to since I’m not trying to win a race.

I'm personally tired of heavy hub motors, but if i had to chose one, this would also be my pick.