Help choosing a bike upgrade

[Gecko6090]

Hi folks!

I have an Ecoride Ambassador X AXS H-9 bike that I love - back hub 60nm motor, 16 Ah battery, quiet ride, cadence sensor, AVS back rack system and a front backet.

The trouble is that I have a new place of living on a very steep hill and the bike just can't make it up the slope, so I'm looking to upgrade it just for that one factor alone. I've been searching for a couple of weeks now and the main issue I seem to run up against is that unless it's a conversion Bafang BBS02B 500W motor, all performance motors are torque-based.

Maybe I am missing something, but a motor that makes you work harder in order to give more power to help you climbing a hill is counter intuitive to me - the entire point of a motor is to help me do less work, not more. For this reason, all torque sensors are out for me - which is quite strange because this is the way the entire ebike industry is going. What am I missing here?

Otherwise, could anyone help me with my bike search? The list is essentially all requirements my Ecoride meets, but with a more powerful motor:

• 80nm torque
• Removable battery
• Battery lock
• Battery 16 Ah/576 Wh or better
• Cadence, not a torque sensor
• Very quiet motor
• AVS back rack system
• excellent hill assist for walking up
• Front basket or flat rack
• 60,000kr tops

Happy to listen to any suggestions - much thanks in advance.

 

[stancecoke]

Maybe I am missing something

Yes, you are missing, that you can set the amplifying factor on a torquesensor system. So you will be able to get full motor power with very little personal effort. You don't have to switch between the levels all the time to adjust your speed, just ride as you would do without a motor.
As far as I know, the BBS02 is the last middrive, that has no torquesensor. But the new ones are with CAN Bus, so it's more difficult to adjust the settings to your individual needs.

The To7 motors can be set to simple PAS levels by the display, so you can try both modes and choose your favourite.

To7motor - Mid Drive Motor

Designed to harness the full potential of the bicycle’s gear system, mid-drive units optimize power distribution for a more efficient ride.

to7motor.com

 

[fill]

Google suggests your bike uses a 36v battery/control system.. you could upgrade that to a 48v battery/controller to provide you with upto 33% more torque with the hills too. Find a dual voltage torque sensor input controller and you can still use your current battery too for less demanding trips or the return down hill leg of longer trips??

 

[stancecoke]

Google suggests

You should not trust in Google, but in physics.
The torque only depends on the motor current, not on the voltage. The motor current is set by the controller. So to get more torque, you need a controller that allows more motor current. The higher voltage only helps for more speed, not for more torque.

 

[E-HP]

You should not trust in Google, but in physics.
The torque only depends on the motor current, not on the voltage. The motor current is set by the controller. So to get more torque, you need a controller that allows more motor current. The higher voltage only helps for more speed, not for more torque.

Torque depends on power. Current or voltage increase will increase torque.

 

[E-HP]

Hi folks!

I have an Ecoride Ambassador X AXS H-9 bike that I love - back hub 60nm motor, 16 Ah battery, quiet ride, cadence sensor, AVS back rack system and a front backet.

The trouble is that I have a new place of living on a very steep hill and the bike just can't make it up the slope, so I'm looking to upgrade it just for that one factor alone. I've been searching for a couple of weeks now and the main issue I seem to run up against is that unless it's a conversion Bafang BBS02B 500W motor, all performance motors are torque-based.

Maybe I am missing something, but a motor that makes you work harder in order to give more power to help you climbing a hill is counter intuitive to me - the entire point of a motor is to help me do less work, not more. For this reason, all torque sensors are out for me - which is quite strange because this is the way the entire ebike industry is going. What am I missing here?

Otherwise, could anyone help me with my bike search? The list is essentially all requirements my Ecoride meets, but with a more powerful motor:

• 80nm torque
• Removable battery
• Battery lock
• Battery 16 Ah/576 Wh or better
• Cadence, not a torque sensor
• Very quiet motor
• AVS back rack system
• excellent hill assist for walking up
• Front basket or flat rack
• 60,000kr tops

Happy to listen to any suggestions - much thanks in advance.

Can you provide the name of a street in your area that you consider steep? Everyone’s idea is different.

 

[Zambam]

Can you provide the name of a street in your area that you consider steep? Everyone’s idea is different.

I'd be interested in what tools you use to check steepness by street name.

 

[docw009]

This bike cannot climb the hill? I don't have a feel for what 60 nm motor, but then all those motor specs are from marketing people. My first thought is that's a small motor with a 36V battery and maybe a 14A controller. Maybe 500w peak.

Controller is in box under the pedals? Could swap in a bigger controller and buy a 48V battery. Then 1000W peak would there and a steady 500 watt possible. Still, can't promise that the motor won;t melt on your hill.

 

[E-HP]

I'd be interested in what tools you use to check steepness by street name.

HeyWhatsThat Path Profiler

Compute elevation profile for an arbitrary path

www.heywhatsthat.com

You just zoom in on the street or trail and map points to show the grade, elevation gain, distance, etc.

 

[stancecoke]

Torque depends on power.

Power is the result of torque and rpm.
The torque is only depending on the motor current. That's one of the basic motor equations.

https://www.maxongroup.com/medias/sys_master/8798985748510.pdf

 

[E-HP]

Power is the result of torque and rpm.
The torque is only depending on the motor current. That's one of the basic motor equations.

two examples of doubling power, one by doubling current, the other by doubling voltage. Voltage increase provides better torque advantage in the real world, if you need torque to accelerate while in traffic. (no torque advantage at 20mph vs 70% advantage).

 

[Gecko6090]

Can you provide the name of a street in your area that you consider steep? Everyone’s idea is different.

Hey, it is Branta Liden in Lerum, near Gothenburg, Sweden. The website pretty much shows a 0 to 60m climb and that doesn't sound too far off from reality.

Here is the google maps link, and the initial steep slope is right when the street branches off. The local police, firemen, and garbage trucks refuse to come up the hill due to its steepness (according to the municipality anyway).

Thanks everyone for your replies - it's a lot of new information, and I am reading through it.

 

[stancecoke]

two examples of doubling power,

We are not talking about power, but about torque.

with upto 33% more torque with the hills too.

Of course with a middrive you can scale the torque with the gear.

 

[E-HP]

Hey, it is Branta Liden in Lerum, near Gothenburg, Sweden. The website pretty much shows a 0 to 60m climb and that doesn't sound too far off from reality.

Here is the google maps link, and the initial steep slope is right when the street branches off. The local police, firemen, and garbage trucks refuse to come up the hill due to its steepness (according to the municipality anyway).

Thanks everyone for your replies - it's a lot of new information, and I am reading through it.

If you check the box for "show grade" on the right of the tool, it will display the grade between each point. Fortunately, the hill is a fairly short climb, so heat will be less of an issue than a longer steep climb.

We are not talking about power, but about torque.

Of course with a middrive you can scale the torque with the gear.

We're talking about increasing voltage vs current, and both increase torque.

 

[E-HP]

Fortunately, your hill is fairly short in distance, and the steepest section looks to be around a tenth of a mile. This is much better with respect to heat concerns, since you just need a short burst to make it past that section. You may even be able to do it with a better battery, since the stock battery is probably sagging voltage a lot in that section. Do you have a way to monitor voltage while riding? If you could see what the battery voltage looks like before the steep section and what it looks like while climbing it, it can tell you where you need to beef up your system.

 

[Gecko6090]

> you just need a short burst to make it past that section.

That's exactly right! I also checked Map Elevation Calculator and the elevation change seems to be way less, just about 20m in a very steep, short section.

> Do you have a way to monitor voltage while riding?

I'm not sure. Have not messed with this yet, and I don't know how to get that information from the cycle computer. I'll look around, any tips are welcome - it is a SPINTECH C3 cycle computer.

 

[stancecoke]

We're talking about increasing voltage vs current, and both increase torque.

No. The motor torque is only defined by the motor current. Simple formula:

torque = motor constant * motor current.

Absolutely no voltage term in this formula.

 

[E-HP]

The torque is only depending on the motor current.

Please explain why torque increases without increasing current.

 

[stancecoke]

Please explain why torque increases without increasing current.

Which working points do you compare?! I don't understand what you want to tell me....
You can't fool physics

The only situation where higher voltage helps is, when the voltage is too low to push the wanted motor current into the windings against the BEMF.

 

[E-HP]

Which working points do you compare?! I don't understand what you want to tell me....
You can't fool physics

In this example, at 15mph. Torque is directly proportional to power:
57.7/33.6 = 1.72
1079/629 = 1.72

Not motor current: 51.1/30.1 = 1.7
or battery current 22/22 = 1

Can you explain why the higher voltage system produces 72% more torque at 15mph?

 

[stancecoke]

Because the controller cuts the battery current. Of course you have to allow a higher battery current with less voltage to get the same power.

Torque is directly proportional to power:

Power = motor current * motor constant * speed (*2Pi)

Tell me why a basic motor equation should not be valid?

 

[E-HP]

Because the controller cuts the battery current. Of course you have to allow a higher battery current with less voltage to get the same power.

Power = motor current * motor constant * rpm (*2Pi)

Tell me why a basic motor equation should not be valid?

So in the real world, the higher voltage system provides more torque, all else being equal.

 

[AdR]

I agree with stancecoke, motors can have max torque based on the current and still put out zero mechanical power

 

[E-HP]

I agree with stancecoke, motors can have max torque based on the current and still put out zero watts of power

Can you explain why when only increasing voltage, torque increases?

 

[stancecoke]

That's just due to the current limits the controller uses, nothing to do with the voltage.
Execept the situation described in #19

What is so difficult to accept, that the torque only depends in the motor current and nothing else!?