Message from the Forum Moderator The 48 Volt 1800 Watt 4400 RPM motor, speed controller, and other parts are available at ElectricScooterParts.com: https://electricscooterparts.com/motors48volt.html https://electricscooterparts.com/speedcontrollers48volt.html A complete ready to kits for the MX500, MX650, and SX500 are also available at ElectricScooterParts.com: https://cart.electricscooterparts.com/store/Search.aspx?searchTerms=razor+MX500+and+MX650+dirt+bike+modification+kit |
Original brushed 650w motor 9 lbs 1.1oz, 134mm L, 107.7mm Diam, 11.9mm shaft Diam.
New brushless 1500w motor 8 lbs 4.7oz 134mm L, 107.4mm Diam, 11.7mm shaft Diam
Original ESC (electronic Speed Controller) 13 oz
Brushless ESC 1 lb 2.4 oz
Overall the new system is about half a pound lighter
The sprocket on the original motor swapped directly on the the brushless motor with no modifications and was a perfect fit so I ran with it. One point to notice is that from the face of the stock motor to the middle of the sprocket was 14mm. From the face of the brushless motor to the middle of the sprocket was 16mm. This was resolved by putting a 2mm washer in between the face of the motor and the motor mount thereby holding the motor back such that the sprocket was in the original position. You'll notice there was a 10mm difference in length so on the backside I needed 8mm spacers to make up the difference. A combination of a spacer and a washer was perfect. Ace Hardware had them. The mounting holes were identical to that of the original motor and the original bolts were long enough that they could be used so the swap was easy. The new ESC is a bit larger but will still fit in the existing location. I placed it up where the 3rd lead battery went as I'm not using that area.
I picked up 2 Controllers as the good folks here at Electric Scooter Parts were kind enough to shoot me a personal email when they saw what I was doing. They accurately noted that if I only got the 48v controller it would likely have a cut off around 36 volts and not allow me to do much testing at 36volts for direct comparison to the stock set up. THANKS GUYS. It was only $45 more to add a 36v controller. Cost was $325 before I added the 2nd controller.
Results will be posted as we get a chance to get it out and tested. Should be over the next two days.
Mounting
Brake lever are aluminum compared to stock as plastic. They are also slightly closer to the handles making them a little better suited to smaller hands of younger folks. Throttle has a voltmeter on it and accurately shows the voltage. It also requires the key to be turned for it to work. The many wires on the controller are clearly marked and can also support brake lights, turn signals, a charge port and something that says 'double speed'. Not sure what that is. There are no instructions.
I installed a volt, watt, current and capacity meter that I bought on Ebay seperately. It fit nicely into the what looks like a gas tank. I'm using a GPS from Eagle Tree to get the speed readings. It holds the highest speed reached so it's not necessary to look down while riding.
Test results
The stock 12v batteries fully charged are 14.4v per battery or 43.2v fully charged. We removed and replaced with 10 cell Lithium Polymer batteries which are 42.0v when fully charged.
With original motor and controller in a small park nearby with a long gentle slope of not more than 1 or 2 degrees we recorded the following and repeated for the new motor and controller.
Original motor
16mph uphill at 22A
17mph downhill at 17A
New motor and 36v controller
18mph uphill at 27A
20mph downhill at 21A
We attempted to run another test with 11 Cells using a combination of the 10s cells just used so partially depleted. Would normally be at 46.2v fully charged but likely around 44volts here. The controller would not arm so we couldn't run it. This controller states 36v or 48v at 500W. My guess is that 44 volts was near the cut off for the 48v set up. Four 12volt lead acid batteries fully charged would be 57.6v so it's reasonable to assume I was in the cut off range. We've replaced the 36v controller with the 48v controller and it arms at 11 cells so we'll test it (may cut off quickly as voltage drops below cut off point) at 11 cells (46.2v), 12 cells 50.4v and possibly 13 cells (54.6v) depending on the current and watts we see in 11 and 12 cell testing. Don't want to over do it.
THanks for posting Jamie, that's some interesting stuff you have going on there.
I believe these are final results until I either change a sprocket or learn how to use the "Double Speed" connector lead from the controller. Tony is looking into it but his supplier is out until the end of Chinese New Year.
Repeated here are the stock results with 10s lipo and the Brushless (BL) motor results on the 36v controller. New are the data from 11s, 12s, 13s and 14s LiPo with the 48v controller. All tests are off road in the grass with just a minor long consistant slope. We tested down the slope then back up.
Downhill runs Uphill runs
Initial battery voltage Current Speed (MPH) Current Speed (MPH)
Stock motor 42V (10s LiPo) 17A 17mph 22 16
BL motor 36v controller 42v 21A 20mph 27 18
BL motor 48v controller 45.5v 20 24 28 19
49.2v (12s LiPo) 21 25 27 21
52.6v (13s LiPo) 22 26 28 23
56v (14s LiPo) 24 27 28 23
With the brushless system you'll notice the current stays pretty steady at 27-28Amps on the uphill runs. I had a separate telemetry system showing me the current real time as the rider also read the built in meter. I noticed that the telemetry system showed the current would run just above 30 amps for a split second then was held below 30amps continuously. I'm assuming the controller is limiting the current going to the motor to 30 Amps. The torque is greatly increased over stock allowing steep uphill runs we tested in a different location.
More results
On 14s LiPo (58v) we managed 27mph on paved surface level to very slight uphill. This was after several test runs up a steep hill. Steep uphill speed results will be shown and compared with results compared to using the 89 tooth rear sprocket which should give a little higher torque and perhaps higher speed during hill climbs compared to the stock 80 tooth rear sprocket.
The "Double Speed" connector coming off the controller was attached to a handle bar push button ordered from the good folks here at Electric Scooter Parts (89mm sprocket as well). When pushing the button to connect the circuit the speed is cut roughly in half. It affects only the top end speed of 27mph being cut to 17mph. Interestingly it didn't affect hill climb speed at all as it was under 17mph at full power. We used this when our younger son wanted to try riding this bigger MX650 bike after having ridden the MX350. It was nice being able to limit the speed for him to give it a try.
More results
On 14s LiPo (58v) we managed 27mph on paved surface level to very slight uphill. This was after several test runs up a steep hill. Steep uphill speed results will be shown and compared with results compared to using the 89 tooth rear sprocket which should give a little higher torque and perhaps higher speed during hill climbs compared to the stock 80 tooth rear sprocket.
The "Double Speed" connector coming off the controller was attached to a handle bar push button ordered from the good folks here at Electric Scooter Parts (89mm sprocket as well). When pushing the button to connect the circuit the speed is cut roughly in half. It affects only the top end speed of 27mph being cut to 17mph. Interestingly it didn't affect hill climb speed at all as it was under 17mph at full power. We used this when our younger son wanted to try riding this bigger MX650 bike after having ridden the MX350. It was nice being able to limit the speed for him to give it a try.
With this 48v 1500 watt motor and stock sprockets my son is now able to get air off a hill that the stock motor/battery set up was lucking just to make it to the top, We did a few more tests on hills to see the difference between stock sprockets and switching rear sprocket from stock 80 tooth to an 89 tooth sprocket from electric scooter parts. While the difference is only about 11 percent and top end speed drop was 1mph the torque increase was huge. My son said he had to get into throttle slowly are start from a roll to avoid popping a wheelie. Soon he was learning to add throttle more slowly to avoid the wheelie. I hopped on and each time I took off with 3/4 to full throttle it popped a wheelie.
Test results in miles per hour. Anywhere a downhill is tested the stock sprockets are slightly faster. Anywhere there is an uphill requiring more torque the 89 tooth sprocket provide the extra torque to go a little faster. The 89 tooth sprocket requires adding 5 links to the existing chain.
Stock sprockets 89 tooth rear sprocket
Up sidewalk very slight uphill 27 27
Down same sidewalk 29 28
In park (grass/dirt) slight downhill 27 26
park slight uphill 23 24
Steep park uphill 10 meter from hill base 11mph 12
Steep park uphill start at base 9 10
The attached photo shows a run up the short steep hill. In the background you can see the incline of the sidewalk where the speed test was run up and down. Ran about 100 meters on the sidewalk.
This project is awesome! I am a motorcycle parts dealer/repair/upgrade shop and we've been playing around with the razor stuff just for our selves (not for clients, we're not an authorized Razor dealer or anything). Sometimes it's really fun to put away the 400+ horsepower Hayabusas and hop on a little electric bike. I was thinking about doing something fun with the MX-650 I've been riding around, and I think this is it. I was thinking of something along the lines of a 48V 22ah lithium battery though since I have one laying around from an electric bike that was stolen while the battery was on the charger. Would love to see a run video of this little beast in action.
carlii
The test results in this forum post are relevant to the discontinued 48 Volt 1500 Watt 5300 RPM Boma brushless motor. We removed the links to the 1500 Watt 5300 RPM motor and replaced them with links to the 48 Volt 1800 Watt 4400 RPM motor. Please be aware the test results posted below will be close to but not the same when using the 48 Volt 1800 Watt 4400 RPM motor.
I posted elsewhere here that I had ordered the motor under a thread about hub motors. New thread for this.