Bafang 750w Motor Upgrade

YES, probably might be superfluous! ;-) Please, set all your other impressions aside. ;-)
Math, it's always just math. An increase in voltage (48V-52V) is not necessarily an increase in Amp hours (Battery Capacity).
I agree with ... As posted above:
Basically, Volt = top speed (Higher Voltage = Increased TOP SPEED) 48V (54.6V fully charged) to 52V, not so much.
Ampere = torque (More TORQUE = EASIER CLIMBING, and gets to top speed QUICKER) What YOU WANTED!
I will add: Amp Hours = RANGE (How long your battery lasts ... capacity)

IMHO: Increasing your controller amperage will reduce your range, but produce greater torque, with a very slight increase in top speed.
If you can live with the decreased range of the 35 Amp controller and your current battery, great. In order to increase your range you will need a battery with more Amp Hours. 48V or 52V, pick one.

A Formula for you: Volts(Battery) X Amps (Controller) (not amp hours) = Watts

Example: My Sondors MXS - 48Volt (battery) X 25 Amp (Controller) = 1200 Watts (power delivered to the motor) At 100% Full throttle or PAS set to100% Here's some What If Numbers:
52 Volts X 25 Amps = 1300 Watts
48 Volts X 35 Amps = 1680 Watts
52 Volts X 35 Amps = 1820 Watts
Simply plug your numbers in the above formula to see the results of any planned changes or current settings.

You have many choices available to you , depending on your preferences. I would probably NOT upgrade the motor or battery until they die. To increase the range of my Sondors (750 Watt) MXS, I run a dual/parallel battery setup. Each is 48Vx17.5 Ah. I run one battery until it's nearly depleted, then engage the second battery. Twice the fun. For easier hill climbing (I pedal), I swapped out my factory 48T chainring for a 42T and will soon be changing my 14T-28T freewheel for an aftermarket DNP 11T-34T one. That should let me cover almost any situation I come across. Good luck.

Also excellent; thanks very much for your input!!!
 

AHicks

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Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
What that math is not accounting for is the motor's ability to get rid of heat. Sure, you can feed it more power to get increased performance, but the question will soon become how long you can expect the motor to maintain that higher performance prior to it melting down. THAT'S how a motor's true wattage rating is determined. How many watts can it handle on a constant basis - without a meltdown.

On a temporary basis, such as climbing a short steep hill, then allowing a cool down period prior to repeating that climb, you can cram a LOT of power into a motor, and get a LOT of performance from it. Stuff like that is done frequently. You just need to be aware of the fact that motor is building heat internally pretty quickly....

Also, increasing a controllers amperage rating is only going to result in decreased range if/when you are using that additional amperage. Otherwise it's a complete non event. For instance, if you are running 10 amps through the stock Rad controller, and 10 amps through the Bolton controller, your range will be the same. From a practical standpoint, the difference will be when you point the bike up a hill. There, the increased amperage available from the Bolton controller will increase climbing performance.
 
What that math is not accounting for is the motor's ability to get rid of heat. Sure, you can feed it more power to get increased performance, but the question will soon become how long you can expect the motor to maintain that higher performance prior to it melting down. THAT'S how a motor's true wattage rating is determined. How many watts can it handle on a constant basis - without a meltdown.

On a temporary basis, such as climbing a short steep hill, then allowing a cool down period prior to repeating that climb, you can cram a LOT of power into a motor, and get a LOT of performance from it. Stuff like that is done frequently. You just need to be aware of the fact that motor is building heat internally pretty quickly....

Also, increasing a controllers amperage rating is only going to result in decreased range if/when you are using that additional amperage. Otherwise it's a complete non event. For instance, if you are running 10 amps through the stock Rad controller, and 10 amps through the Bolton controller, your range will be the same. From a practical standpoint, the difference will be when you point the bike up a hill. There, the increased amperage available from the Bolton controller will increase climbing performance.

Thanks. This sounds closer to my initial guess-timation; that the physically larger "true" 750W motor has more windings, maybe uses heavier gauge copper, and can therefore probably handle higher currents for longer periods without overheating. What I did not fully understand is how this difference relates to the rated torque of the motor itself -- i.e., independently of the controller/battery that it is connected to -- and again more specifically why the stock RPB motor and the larger upgraded motor are both spec'd for 80nm of torque. However I am just going to accept on faith that the upgraded motor will in fact deliver more torque (for whatever reason).

Thanks again for everyone's input.
 
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Here is a link to an article reviewing test results of various ebike motors. It contains rated vs. actual measured specs.



My guess is the Rad motor is 500 watts nominal / 750 watts peak. This means it will run continuously at 500 watts for perhaps days/weeks/months without issues or at up to 750 watts continuously for maybe 15-60 minutes before it overheats and permanent damage is done. Timeframe is pure speculation on my part.

The “true” 750 watt motor may use a thicker gauge wire and have more windings yielding a more robust device. It may run continuously for days/weeks/months at 750 watts without issues and perhaps 15-60 minutes at 1000 watts before overheating and damage occurs. However, it appears the upgraded motor fits into the stock motor housing, so I worry about heat dissipation a bit at high wattages also.

Both can probably handle much higher wattage for a few seconds of instant acceleration followed by a cool down period before being subjected to such a high load again.

I personally would not go to the higher output controller without upgrading the motor also. I think that will eventually lead to an overheated and damaged stock motor if used regularly in a hilly area or to accelerate rapidly as a standard practice while biking.


Good luck in your pursuit of the perfect motor and enjoy the ride also! - RangerDave
 

AHicks

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USA
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Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
Another way of looking at running the smaller motor on the Bolton controller - IF - you manage to smoke it, who cares? You are out nothing more than if you had replaced the motor with the bigger one to begin with, other than maybe the walk home with a smoke trail (from the burnt motor) following you
 

Timpo

Well-Known Member
Not trying to hijack this thread, but has anyone tried Bafang G062?

This looks like a bigger brother of Rad Power / Bolton's Bafang G060.

It has 85Nm, also high revving 400rpm.
So it's superior to G060.

BAFANG 48V 1000W Hub Motor RM G062 Bafang Electric Bike Hub Motor Fat Bike  Freewheel Electric Bicycle Rear Motor Ebike| | - AliExpress
 
Not trying to hijack this thread, but has anyone tried Bafang G062? ...

Interesting. One immediate concern is whether this motor is seamlessly swapable with the existing case of the stock RPB motor? -- i.e., without having to re-lace the rear wheel spokes. A second concern is the connection to the motor controller -- i.e., whether it is "plug-and-play" or requires a custom cable. These are among the benefits of the Bolton/EBW motor -- they don't require special skills/tools/parts to install on the stock RPB bikes.
 

Timpo

Well-Known Member
Interesting. One immediate concern is whether this motor is seamlessly swapable with the existing case of the stock RPB motor? -- i.e., without having to re-lace the rear wheel spokes. A second concern is the connection to the motor controller -- i.e., whether it is "plug-and-play" or requires a custom cable. These are among the benefits of the Bolton/EBW motor -- they don't require special skills/tools/parts to install on the stock RPB bikes.
The G062 will more than likely require re-lacing as it has different external casing.
Not sure about the connector, looks slightly different?

4
 

AHicks

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Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
Thanks for posting Tempo. I keep seeing mention of a 1000w Bafang, but you don't see much info about it or anyone using it in production bikes.

For my purposes (no interest in speeds over 20mph), the higher rpm rating is of concern here. Low speed ratings = more grunt/low speed torque. When the motor is wound for speed, the grunt is sacrificed. Kind of like a cam in a 4 stroke engine. You can have outstanding torque available at lower rpm, or you can have one that makes a bunch of HP at higher rpm. But you can't have both....

More relevant maybe, is the fact that the MAC motors are available with differently wound armatures for different applications/owner preferences. They're available with 6, 8, 10, and 12 turn windings. More turns = more low speed torque. Fewer turns = more speed. Their 12 turn motor is commonly accepted as having the most torque available anywhere - until you get into the mid drives anyway. -Al
 

theemartymac

Well-Known Member
A couple of points:

Bafang over-rates their torque by a country mile. It's been independently tested on a few sites. They also seem to rate the best "possible" performance for the motor, not the actual performance with a bundled controller. The builder chooses the controller to use and the firmware profile to include, but they don't control the companies torque ratings. That's all Bafang marketing. And also why simple upgrading the motor won't necessarily give you the full potential of the new unit unless the controller and firmware are matched, as others have mentioned previously.


And the overvolted batteries (e.g. 52V on a 48V motor), don't necessarily give any more range. They do keep the supplied voltage above the ideal threshold (+48V) for longer, so they 'seem' to give more range at peak torque, but they drop off just as fast at the end. They also have a higher low voltage cutout, so they can't be run down as far as the lower voltage battery. That's why many builders offering the 52V battery as an upgrade option aren't really adding much if any extra range to their estimates.

And I can attest that it's easy to overheat a bafang 750 hub. I'm a big guy, and I can fault mine on any hill over 7-8% if I run too slow for more than 4-5 minutes. If I keep my speed above 10kph, I'm pretty good for any of the hills I encounter (<5min climbs). My 1000w Ultra mid-drive is the solution to the hills around here, as it's absolutely unstoppable.
 

Timpo

Well-Known Member
A couple of points:

Bafang over-rates their torque by a country mile. It's been independently tested on a few sites. They also seem to rate the best "possible" performance for the motor, not the actual performance with a bundled controller. The builder chooses the controller to use and the firmware profile to include, but they don't control the companies torque ratings. That's all Bafang marketing. And also why simple upgrading the motor won't necessarily give you the full potential of the new unit unless the controller and firmware are matched, as others have mentioned previously.


And the overvolted batteries (e.g. 52V on a 48V motor), don't necessarily give any more range. They do keep the supplied voltage above the ideal threshold (+48V) for longer, so they 'seem' to give more range at peak torque, but they drop off just as fast at the end. They also have a higher low voltage cutout, so they can't be run down as far as the lower voltage battery. That's why many builders offering the 52V battery as an upgrade option aren't really adding much if any extra range to their estimates.

And I can attest that it's easy to overheat a bafang 750 hub. I'm a big guy, and I can fault mine on any hill over 7-8% if I run too slow for more than 4-5 minutes. If I keep my speed above 10kph, I'm pretty good for any of the hills I encounter (<5min climbs). My 1000w Ultra mid-drive is the solution to the hills around here, as it's absolutely unstoppable.
ok? so if you think your Bafang 750W (G060 I assume?) isn't heavy duty enough, why don't you just get a G062 1000W rated motor?

You can be our guinea pig and report back 😁 👍

 

Timpo

Well-Known Member
Thanks for posting Tempo. I keep seeing mention of a 1000w Bafang, but you don't see much info about it or anyone using it in production bikes.

For my purposes (no interest in speeds over 20mph), the higher rpm rating is of concern here. Low speed ratings = more grunt/low speed torque. When the motor is wound for speed, the grunt is sacrificed. Kind of like a cam in a 4 stroke engine. You can have outstanding torque available at lower rpm, or you can have one that makes a bunch of HP at higher rpm. But you can't have both....

More relevant maybe, is the fact that the MAC motors are available with differently wound armatures for different applications/owner preferences. They're available with 6, 8, 10, and 12 turn windings. More turns = more low speed torque. Fewer turns = more speed. Their 12 turn motor is commonly accepted as having the most torque available anywhere - until you get into the mid drives anyway. -Al
well I guess if you're not interested in higher rev, it doesn't make much sense I guess. :confused:
 

theemartymac

Well-Known Member
ok? so if you think your Bafang 750W (G060 I assume?) isn't heavy duty enough, why don't you just get a G062 1000W rated motor?

You can be our guinea pig and report back 😁 👍

Lol, I thinks it's just fine round town, so I don't need to upgrade now that I've learned it's shortcomings. I've kitted that one out for errands and grocery runs around town.

And the 1000W Ultra mid drive is 100% the right solution to my fat ass for the coastal hills! It's my work commuter and long-distance explorer. ;-)

But I do think I'll swap in a new motor and controller on the hub bike one day, but after I wear this one out and at least get a ways off the warranty period. Don't hold your breath for that DIY thread. lol
 

AHicks

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Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
Lol, I thinks it's just fine round town, so I don't need to upgrade now that I've learned it's shortcomings. I've kitted that one out for errands and grocery runs around town.

And the 1000W Ultra mid drive is 100% the right solution to my fat ass for the coastal hills! It's my work commuter and long-distance explorer. ;-)

But I do think I'll swap in a new motor and controller on the hub bike one day, but after I wear this one out and at least get a ways off the warranty period. Don't hold your breath for that DIY thread. lol
You mentioned your weight in another note somewhere. So you know, we're both in the 300 club. Just wanted to share that the mid drive Bafangs are not the only answer for guys our size when it comes to hills. The MAC 12t is rated at 110nm or so, and the GMAC's are just a little less. These are both high quality hub drives with PLENTY of power to climb about anything paved with our "plus" sizes aboard. Downside with the MAC's is that you have to build/convert a bike on your own. For some unknown reason, very few production bikes use them. Just an FYI. -Al
 

Timpo

Well-Known Member
You mentioned your weight in another note somewhere. So you know, we're both in the 300 club. Just wanted to share that the mid drive Bafangs are not the only answer for guys our size when it comes to hills. The MAC 12t is rated at 110nm or so, and the GMAC's are just a little less. These are both high quality hub drives with PLENTY of power to climb about anything paved with our "plus" sizes aboard. Downside with the MAC's is that you have to build/convert a bike on your own. For some unknown reason, very few production bikes use them. Just an FYI. -Al
MAC is used by Juiced for their HyperFat and HyperScorpion models.

GMAC have been used by HillEater and WattWagons.
 

AHicks

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Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
The cable entry is from the side , not thru the center axle. How you install that is anyone’s guess.
Nice catch on the cable exit. I hadn't noticed that. Pretty great feature actually, allows for the use of much larger wire for example, not to mention a much stronger axle. Install is easy. If you look at the closeup it's easy to see there's a spacer the axle disappears into. That would prevent the cable from becoming pinched.

It's too bad they didn't set up a torque arm arrangement like MAC did. Maybe we can look forward to something like that later.