What is bottlenecking me?

[stonestonestone]

So is it the Australian fat tire 20x4" tire folder? The readers here can't do much without knowing about the bike. Your RM G0C0.D is rated pretty low on torque, 32 nm, a lot less than what they usually put in a fat tire bike.

Where were you able to find the specs for the motor? Couldn’t find anything online

 

[harryS]

Where were you able to find the specs for the motor? Couldn’t find anything online

You never answered the question about whether it's that australian model, where the cops tackle illegal ebikes,

 

[PedalUma]

I agree. With the tough ones I will apply some heat before the oil. As the piece cools and contracts it seems to draw the oil in.

 

[stonestonestone]

You never answered the question about whether it's that australian model, where the cops tackle illegal ebikes,

@harryS It seems to be the same as that australia model- minus the tires. I gave a link to an israeli website with the exact bike

 

[stonestonestone]

What is the continuous amp rating of your controller? Your battery is sufficient. Your controller regulates the amps to the motor. More amps = more power/speed.

Finally got access to the controller, 48v Rated 6A, Max Current 13A

 

[stonestonestone]

While I prefer screw extractors, that's last resort. Cutting a slot with a dremel and using a flat bladed screwdriver works for some people. Those are just coarse screws in a cheaply tapped aluminum boss. Or get a new Phillips screwfriver with a sharp tip, give it a tap with a hammer to sink it into the soft screws, and see if you can spin them out while pressing hard against the screw. Hit them with some penetrating oil and let it soak in for an hour before trying to torque them out,

Dremelling a slot worked like a charm!

 

[Tom@WashDC]

Finally got access to the controller, 48v Rated 6A, Max Current 13A

Well that means you are running a "nominal" 288-300 watts which is about as weak as it gets. Cannot expect much from that combo.
I'm running 48V at 30 amps which is a nominal 1,440 watts, peaking at 1600.

 

[Chargeride]

Don't upgrade without checking the rating of the wiring and connectors to the drive.

 

[stonestonestone]

Well that means you are running a "nominal" 288-300 watts which is about as weak as it gets. Cannot expect much from that combo.
I'm running 48V at 30 amps which is a nominal 1,440 watts, peaking at 1600.

So a new controller with higher amperage would up my speed? How do I know which to buy, so that I don’t completely burn out my motor?

 

[Tom@WashDC]

So a new controller with higher amperage would up my speed? How do I know which to buy, so that I don’t completely burn out my motor?

Well, you don't.
You really need to know the max rating of your motor, and max temp rating. That being said, the ratings may be a good guide, but lots of riders pump more amps through the motor than they are technically rated for. The danger is in overheating any one of the motor components or wires depending on the load, and time under load. If I had to guess, you could go to a 12-15 amp controller, but that would be my guess, and I would risk it on MY motor. Get a controller that will allow you to adjust the amperage output, such as a 21 amp KT Controller. You will need a matching KT display.

First I would read this:

Futility of Motor Power Ratings

"There's no such thing as a rated watt!" Read here for why we don't advertise a simple power rating for the motors we sell. Also, have a look at our Youtube video where Justin talks about the power to propel bicycles in <a href="https://www.youtube.com/watch?v=ALde6zhLPs0">"School of Watts"</a>.

ebikes.ca

And this: https://ebikes.ca/tools/simulator.html

Paying attention to this:

• Overheat In: This is a prediction on how long it would take the motor to overheat (reach 150oC) from the starting temperature of the simulation, based on a comprehensive thermal motor model taking into account both the motor RPM and passing air velocity. If the motor has not had been thermally characterized in our wind tunnel, then it will say "Not Modeled" instead.
• Final Temp:This is a prediction of the motor core temperature after running for 2 hours at the current conditions for phase current, rpm, and velocity. The text will appear red if the final temp is over 150 oC. It is very common to run hub motors for short times at loads that cannot be sustained continuously, most steep hills are over in a matter of minutes rather than hours.

 

[stonestonestone]

Well, you don't.
You really need to know the max rating of your motor, and max temp rating. That being said, the ratings may be a good guide, but lots of riders pump more amps through the motor than they are technically rated for. The danger is in overheating any one of the motor components or wires depending on the load, and time under load. If I had to guess, you could go to a 12-15 amp controller, but that would be my guess, and I would risk it on MY motor. Get a controller that will allow you to adjust the amperage output, such as a 21 amp KT Controller. You will need a matching KT display.

First I would read this:

Futility of Motor Power Ratings

"There's no such thing as a rated watt!" Read here for why we don't advertise a simple power rating for the motors we sell. Also, have a look at our Youtube video where Justin talks about the power to propel bicycles in <a href="https://www.youtube.com/watch?v=ALde6zhLPs0">"School of Watts"</a>.

ebikes.ca

And this: https://ebikes.ca/tools/simulator.html

Paying attention to this:

• Overheat In: This is a prediction on how long it would take the motor to overheat (reach 150oC) from the starting temperature of the simulation, based on a comprehensive thermal motor model taking into account both the motor RPM and passing air velocity. If the motor has not had been thermally characterized in our wind tunnel, then it will say "Not Modeled" instead.
• Final Temp:This is a prediction of the motor core temperature after running for 2 hours at the current conditions for phase current, rpm, and velocity. The text will appear red if the final temp is over 150 oC. It is very common to run hub motors for short times at loads that cannot be sustained continuously, most steep hills are over in a matter of minutes rather than hours.

Thanks for the advice. I was trying to find a controller to fit the specs on aliexpress and got a little confused. Could you send a link for one, just so I know what I should be looking for?

 

[Tom@WashDC]

This should work: Controller with LCD3 or LCD8 Display. 48V, 12amps rated, 25max amps.
If you can find a KT Controler with a higher (rated/nominal) amp rating, you can go with that, as the display allows you to customize the amp output.

12 amp KT Controller

18 amp KT Controller

LCD8 Dispaly

 

[Slaphappygamer]

This should work: Controller with LCD3 or LCD8 Display. 48V, 12amps rated, 25max amps

KT Controller

That seller is legit. I got the same kit from them. I went with the LCH8, because the settings are easy to read and work with.

Since my controller is also in the frame, I measured the existing controller and went with the one with the highest max current and a similar physical size as my existing one. I then cut up some foam to the new controller dimensions and did a test fit. That way I knew, without a doubt, that the new controller would fit in the frame.

 

[harryS]

You're probably going to want a controller that fits in the compartment under the pedals. Since that's pretty much a generic frame, similar to my old Ecotric, the small 20A KT (hard to find) probably controller fits well and would do about 24-26 mph on 48V. I kept the 36V motor on my bike, and it topped out around 20 mph. I would typically ride at 12-14 mph.

If you ride like an adult, 20A won't melt the motor.



How good are your solder skills? And how does the motor cable connect to tour controller?

Most of these bikes have a molded 9 pin connector coming off the motor to allow taking off the rear wheel. Then that either goes directly into the controller or uses three bullets and boxy six pin plugs,

So it helps to know what kind of connectors you use when selecting a controller.

 

[stonestonestone]

Well I guess its time for me to replace the controller out of necessity...I lent my bike to a friend, and upon returning it, my headlights would turn on, but the bike and screen would not turn on... Opened up my controller and found this:

He said he rode around with another guy on the back of the bike! What a great way to burn out the board I guess?

 

[stonestonestone]

You're probably going to want a controller that fits in the compartment under the pedals. Since that's pretty much a generic frame, similar to my old Ecotric, the small 20A KT (hard to find) probably controller fits well and would do about 24-26 mph on 48V. I kept the 36V motor on my bike, and it topped out around 20 mph. I would typically ride at 12-14 mph.

If you ride like an adult, 20A won't melt the motor.

View attachment 171823 View attachment 171824

How good are your solder skills? And how does the motor cable connect to tour controller?

Most of these bikes have a molded 9 pin connector coming off the motor to allow taking off the rear wheel. Then that either goes directly into the controller or uses three bullets and boxy six pin plugs,
View attachment 171825View attachment 171826
So it helps to know what kind of connectors you use when selecting a controller.

Have a link to one of those small form factor, higher amperage controllers? Also, does it make a difference if its sine or square wave (and how do I check)

 

[stonestonestone]

How can I tell if

This should work: Controller with LCD3 or LCD8 Display. 48V, 12amps rated, 25max amps.
If you can find a KT Controler with a higher (rated/nominal) amp rating, you can go with that, as the display allows you to customize the amp output.

12 amp KT Controller

18 amp KT Controller

LCD8 Dispaly

These are a little too big for my compartment- I think I'm gonna go with this 36v-48v 20A 500w controller. Do you think this might be too overpowered for my 250w motor? (I could go down to this 17A option.) @harryS

 

[Slaphappygamer]

Really, without having the new controller in hand, the only way would be to get the measurements of the controller you are looking to purchase and cut cardboard to that size. Then see if it fits. Cardboard is convenient, but foam is better. I’ve seen people just cut a piece of wood to observe a test fit. Play dough would also work.

 

[Tom@WashDC]

How can I tell if

These are a little too big for my compartment- I think I'm gonna go with this 36v-48v 20A 500w controller. Do you think this might be too overpowered for my 250w motor? (I could go down to this 17A option.) @harryS

I'd go with the 17a model. On the KT controller you can modualte the power level (amps) going to the motor

 

[stonestonestone]

Really, without having the new controller in hand, the only way would be to get the measurements of the controller you are looking to purchase and cut cardboard to that size. Then see if it fits. Cardboard is convenient, but foam is better. I’ve seen people just cut a piece of wood to observe a test fit. Play dough would also work.

My previous controller fit pretty snug- so I'm only going with something that size or smaller