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Quote from: springer03 on February 13, 2021, 09:22:58 AM
OK, I have another question, I've been reading and trying to understand the relation of the number of strand bundles to torque and speed.
If I understand correctly the 750w (6) will have a slightly higher top speed and lower, low speed torque?
And the 750w (7) will have slightly higher low speed torque?
I ask because I live in a area with a lot of steep hills and I have some nerve damage in my legs and don't have a lot of strength for hard pedaling.
I have the 2020 Radrover (26 inch Wheels) and my wife has the Radrunner Plus (20 inch wheels) Which if I understand correctly it
is better on hills than the 26 inch wheels.
If having the (7) strand version would be a little more helpful on inclines I'll just install the (6) on her bike and order The (7) for mine.
I guess what I'm asking is, will the (7) be better on hills and will the (6) be faster?
Will the (7) have a better 0 to 20mph time? The (6) have better 20+ acceleration?
Thanks!
Quote from: Altema on February 12, 2021, 06:58:16 PMQuote from: JTK77 on February 11, 2021, 12:08:29 AMController is the 35 amp version sold by Electro Bike World and Bolton. Display is the usual KT-LCD3. Wheel size is set to 23 inches, actual wheel diameter is 22. 23 was the most accurate according to GPS. Wheel speed is 351.592, which makes the motor RPM 1757.96 because of the 5x gear reduction. I erred in the last post, and looking back through my notes the voltage was 54.0, not 58.3. The Radmini would require less effort due to the smaller diameter wheel, perhaps that's why it was pulling 200? By 23 mph, it was barely, and took a while getting there. If there is no limiter in the Rad motor, then the rating is 32.55 kV.Quote from: Altema on February 10, 2021, 06:07:36 PM
I'm using 52 volt batteries, and did my test with a near-full charge of 58.3 volts. Would the cutoff when hitting the no load RPM be that sudden? The motor pulls around 1500 watts at 20mph, then drops to 200 watts at 23? I'm just asking because the behavior seems odd.
What controller and display do you have? What wheel size setting and max speed setting? What exact when speed rear wheel of the ground and full throttle (and what voltage at that moment on display)? Any marking on the motor casing from Bafang?
Speed of 23 mph on Rover requires ~500w of power...so you need quite heavy pedaling effort (~300w) at 23 mph?
Typically 5 to 7 mph from peak power speed to no load speed.
Quote from: Altema on February 10, 2021, 06:07:36 PM
I'm using 52 volt batteries, and did my test with a near-full charge of 58.3 volts. Would the cutoff when hitting the no load RPM be that sudden? The motor pulls around 1500 watts at 20mph, then drops to 200 watts at 23? I'm just asking because the behavior seems odd.
Quote from: Altema on February 10, 2021, 07:39:01 AMQuote from: JTK77 on February 10, 2021, 01:59:33 AMUnderstood on the bundles. I've had three different controllers on this particular Rad motor, and the no load speed is 40km even if set to 70km. You can watch the power being throttled above 32km regardless of controller, so that makes me think the motor has an RPM limiter.Quote from: Altema on February 07, 2021, 01:42:47 PMQuote from: JTK77 on February 03, 2021, 10:31:33 AMJust to be clear, the windings on both motors is single strand solid core copper. The Rad kV cannot be determined because the internal limiter prevents the motor from reaching it's natural freewheel RPM.
Yes. Multistrand winding enables more copper fill. That's why the G060.750 can have thinner coil strand but still faster kv (in this case).
In overall the efficiency increases little but this is mostly beneficial in terms of fewer watts wasted in overheating as copperlosses. The difference naturally increases with more power used and is further effected by the increased copper temperature (increase in R).
I had the 750+52v+35A setup few years back but now running vented G062.1000 at 60v 40A..and going soon to custom 45-50A sinewave and custom 60v 24Ah 150A BT battery.
What controller are you using for your new setup? I'm keeping my eye out for a sinewave controller instead of the cheap trapezoidal wave controller like I have now. It gets the job done and put 1600 watts through the stock Rad motor for 600 miles, but the noise and lack of efficiency still annoys me.
Yes, the strands are single but every "turn count" is made of bundle of these wires (bundle is "multistrand").
The speed limiter is in the controller. On stock one you can set speed to 40kmh and change wheel size to min and then test no load speed calculating back to correct wheel size. With LCD3 or LCD8h you only need to play with wheel size is no load speed is more than 72kmh (I have currently just over 80kpm with current setup)
The new controller kit is custom KT version. The idea is cost effective Plug n play kit for 48v to 60v batteries. Will be verions for G060 (z916 motor cable) and G062 (L10 motor cable). Battery connection 10awg with xt90. PCB will be conformal coated.
Your controller sounds interesting, so let me know if you start selling them. I always prefer the XT90, and use the sparkless version for batteries. My rack battery came with the mid size Anderson connector, which I feel is inferior and bulky. I could not find a panel mount version of the XT90, so I had to use the XT60 for accessory connections to the rack battery.
Quote from: Altema on February 07, 2021, 01:42:47 PMQuote from: JTK77 on February 03, 2021, 10:31:33 AMJust to be clear, the windings on both motors is single strand solid core copper. The Rad kV cannot be determined because the internal limiter prevents the motor from reaching it's natural freewheel RPM.
Yes. Multistrand winding enables more copper fill. That's why the G060.750 can have thinner coil strand but still faster kv (in this case).
In overall the efficiency increases little but this is mostly beneficial in terms of fewer watts wasted in overheating as copperlosses. The difference naturally increases with more power used and is further effected by the increased copper temperature (increase in R).
I had the 750+52v+35A setup few years back but now running vented G062.1000 at 60v 40A..and going soon to custom 45-50A sinewave and custom 60v 24Ah 150A BT battery.
What controller are you using for your new setup? I'm keeping my eye out for a sinewave controller instead of the cheap trapezoidal wave controller like I have now. It gets the job done and put 1600 watts through the stock Rad motor for 600 miles, but the noise and lack of efficiency still annoys me.
Quote from: springer03 on February 06, 2021, 11:35:50 AMQuote from: JTK77 on February 03, 2021, 09:34:59 PMQuote from: fin_rad on February 03, 2021, 08:01:41 PMQuote from: Altema on January 20, 2021, 11:30:39 AM
The Bafang model number is RM G060.750.D 06
Rad controller limits the motor power. The Rad motor internal RPM limiter limits the speed.
Is there any stamps on the motor (inside or outside) where I could identify which model the motor is? Just being curious and interested in learning how the ebike systems work.
The meaning of Bafang model markings:
G060 = casing identification
750 = nominal rating
D = freewheel (DC = freehub)
(6) = winding identification (smaller is faster, no it directly equal to KV)
All Power versions within same casing series are swappable.
Rated model not possible to say what from casing as OEM customers can have custom labeling or motor core can ne swapped.
Rad has done both. In the past casing swap (+sticker) and nowadays custom labeling.
KV can ne identified by no load speed (wheel of the ground full throttle) If you have the throttle.
I just received this same motor RMG06 48V750W(6) from Bolton for my radrover 5 and had noticed the one Electric bike world sells is RMG06 48V750W(7)
would there be a noticeable difference in torque between the two? On hills?
I would have preferred more torque for hills, but would rather not return the one I already have if the difference is minimal and not really noticeable.
(I also do have the 35amp controller on order)
Thanks.
Quote from: fin_rad on February 03, 2021, 08:01:41 PMQuote from: Altema on January 20, 2021, 11:30:39 AM
The Bafang model number is RM G060.750.D 06
Rad controller limits the motor power. The Rad motor internal RPM limiter limits the speed.
Is there any stamps on the motor (inside or outside) where I could identify which model the motor is? Just being curious and interested in learning how the ebike systems work.
Quote from: Tony on February 03, 2021, 01:42:04 PM
I have the 35 amp Controller on order so I understand that should be a good improvement for the euro 250. I was thinking of adding the 750 motor as I would like some extra power for hills especially carrying some cargo. Top speed not really necessary.
Quote from: Tony on February 03, 2021, 11:50:39 AM
You think the proper 750 watt motor would be a noticable upgrade over the euro 250 model though ?
Maybe the euro model is a restricted 350/500 motor.
Quote from: Altema on January 19, 2021, 02:12:31 PM
I went ahead and bought the "upgrade" motor for my RadMini. It wasn't a need, and I bought it partly out of curiosity, but it provided a nice opportunity for testing and comparison.
If you spend any time on e-bike websites and forums, I'm sure you've heard the claim that Rad motors are not "true" 750 watt motors, and you need to buy an upgrade. This idea started in an online forum, then became popular through YouTube. Oddly, most opinions on this are based on looks, and while there are many things you can determine by looks, electrical specifications are not one of them. That being said, I do like the motor and will be keeping it. It's a high quality unit and worth the money, depending on your needs.
Side by side comparison
The Rad and upgrade motors do have some differences in design. Most notable is the magnet shell. This is narrower on the Rad motor, and wider on the upgrade. What does this mean? It means the shell is wider. What seems to throw people off is that the Rad motor has this empty space between the stator windings and the mounting plate. The upgrade motor does not have this space... or does it? It turns out the upgrade motor also has an empty space. It's just in a different location.
Although it seems the upgrade motor has bigger windings, in reality, it does not. The stator coils are the same size, as are the magnets.
The installation of the new motor itself went fine, with only one hitch: I was using a cast bit to remove the T-20 Torx head screws with anti-tamper pins, and the bit shattered. To avoid that, I purchased a forged Craftsman folding driver set, and used a butane mini-torch to soften the Locktite for the screws. The only settings changes required to the controller display was changing the speed pulse sensor (P2) from five to six.
Doing the math
I was a bit surprised when I could not get the motor specifications, so I had to do some testing on my own. Below are the results.
Stock Rad motor
Top speed: 23 mph
22 inch wheel RPM at 23 mph: 351.592
Motor RPM at 23 mph: 1757.96 (351.592 x 5)
Motor rating: 32.55 kV (approximate - electronically limited)
-------------
Bafang upgrade motor
Top speed: 27.4 mph
22 inch wheel RPM at 27.4 mph: 418.85
Motor RPM at 27.4 mph: 2094.26 (418.85 x 5)
Motor rating: 38.78 kV
The Rad kV rating is an estimate because it has a built-in limiter that starts reducing power electronically, so the motor is not free to reach it's natural RPM. The Bafang upgrade motor does not have this limiter, and this was one of the reasons I wanted to try it out. You can see the difference on the wattage being used at top speed: The Rad motor is only pulling a couple hundred watts at top speed, even though over a thousand watts is available, while the upgrade motor actually is pulling over a thousand watts at top speed.
Acceleration and hill climb tests
Tests with both motors were done on a RadMini 4 with dual batteries and a 35 amp controller, battery voltage at 54.3 volts, and the tires at 12 PSI. Performance would be better with more air in the tires, but since the first tests were done at low pressure, I kept them the same.
Original Rad motor 0 to 20 mph: 4.9 seconds
Bafang upgrade motor 0 to 20 mph: 4.9 seconds
Wait, what? You read that right, and I ran the tests multiple times. The motors had the same acceleration times. They are both a blast to ride with the 35 amp controller, with the Rad motor pulling ahead off the line and the upgrade motor catching it.
The hill climb test was a bit more subjective, but basically I drove up an absurd 28% grade berm for a freeway overpass. The Rad motor seemed to have a bit more low RPM torque, getting up without me touching the pedals. The upgrade motor had a little harder time, and although it made it, it was not as confidence inspiring.
In top speed, there was no comparison. The Rad motor can hit 23 mph if you change your settings, but the power starts being electronically reduced above 20. If you are already riding at 20 mph and go full throttle, the response is like "Well, ok, give me a minute" as it gradually gathers momentum on the restricted power. With the upgrade motor, it's prime time, and giving the throttle a full twist at 20 mph responds with the attitude of "Hold my beer!". Yes, it does top out at 27/28 mph because kV x voltage = RPM, but it gets you there decisively.
In conclusion, if you have off road or private areas where you can safely use the extra speed, the Bafang upgrade motor is worth every cent. If you need to keep it locked to 20 mph though, the Rad motor will do the same job and can handle the 1,600 watt power levels fine.
