What is bottlenecking me?

stonestonestone

New Member
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USA
I recently bought a preowned Smartbike M3. I haven’t been getting the speeds I was expecting from the battery motor pairing though.
The battery is a 3 cell 48v 16ah.
Motor is a bafang 48v 250w (when I scan the QR code on the motor it says RM G0C0.D 11 F2VA110061).
Controller says Model:FR-TDN01Z, Engine Power 250w
I put the battery in my friend’s bike, which also has a 48v 250w motor, and he can zip up the hills at 30kmh, while I get about 14.
What could be holding me back? Aged battery? bad motor? need new controller?
Stuck scratching my head here.
 

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I recently bought a preowned Smartbike M3. I haven’t been getting the speeds I was expecting from the battery motor pairing though.
The battery is a 3 cell 48v 16ah.
Motor is a bafang 48v 250w (when I scan the QR code on the motor it says RM G0C0.D 11 F2VA110061).
Controller says Model:FR-TDN01Z, Engine Power 250w
I put the battery in my friend’s bike, which also has a 48v 250w motor, and he can zip up the hills at 30kmh, while I get about 14.
What could be holding me back? Aged battery? bad motor? need new controller?
Stuck scratching my head here.
Controller. Generally cheaper bikes are more expensive to maintain. Also check your programing of the display. If you are in Euro-Zone mode that would explain the sulkiness. Enter 1919 into the speed limit after double clicking and holding the 'I' button and then scrolling through the menus. Report back on the results.
 
Controller. Generally cheaper bikes are more expensive to maintain. Also check your programing of the display. If you are in Euro-Zone mode that would explain the sulkiness. Enter 1919 into the speed limit after double clicking and holding the 'I' button and then scrolling through the menus. Report back on the results.
The display is an APT 450U. the SPL (Speed limit) is set to 40 i can set it up to 45.
There are some other settings also in the PSd protected area that are not mentioned in the manual. CUL is 15 and HAL is 06 and theres ASS Hd6 and Hdp
 
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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.
 
I have no experience with that display and controller. It could be the AMPs setting or even a corroded or partial battery connection. I wish I had the answer for you. It reminds me of a guy who played a joke on his buddy by taking the number of PAS magnets in programing from 12 down to 6.
 
The only Google link for a Smartbike M3 is a 20" fat tire folding bike in Australia, As a class of bikes, those should reach 30km/hour on 36V, more on 48V. Check for disk brake binding or tire hitting the frame.
 
The only Google link for a Smartbike M3 is a 20" fat tire folding bike in Australia, As a class of bikes, those should reach 30km/hour on 36V, more on 48V. Check for disk brake binding or tire hitting the frame.
heres the link to the bike. no brake binding or tire-frame play
 
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.
cant get to the controller itself :( the screws are all stripped. ill see if i can check through retailer or bike model number
 
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. Way too small for the tire drag, in my opinion.

How are you getting top speed? With throttle or pedal assist?

There is probably a connector loop on the controller that limits what power this motor puts out, so you should think about getting those stripped screws off,
 
How steep are the hills? On a 6.1% grade, I found that a 750 watt Radrunner was producing about 500 watts, and a 500 watt Radmission produced about 350. Radpower's figures were the electrical power fed to the motors, not their mechanical output.

I believe a mechanical output of 250 watts is about 183 pound feet per second. Guessing your gross weight at 220, that power would lift your bike 0.83 foot per second. If my calculation is correct, 14 kmh is 12.75 feet per second. Lifting you at 0.83 feet per second at that speed would mean a 6.5% grade, as a rough estimate, ignoring rolling resistance and air drag.

I don't know how steep your hills are, but I think you may be getting 250 watts and your friend is getting more than 500.
 
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. Way too small for the tire drag, in my opinion.

How are you getting top speed? With throttle or pedal assist?

There is probably a connector loop on the controller that limits what power this motor puts out, so you should think about getting those stripped screws off,
I believe these tires are only 3”. Top speed with throttle (pedal assist adds a few kph extra). will work on getting to that controller
 
On smooth, level pavement with no wind, rolling resistance and air drag at 30 km/h would take a bit more than 250 watts. If your friend climbs even very gentle hills at that speed, he must be putting more than 250 watts on the ground.
 
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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,
 
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,
... 👍
 
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