Upgrading mx500, should I use 36v or 48v?

[rudyauction509]

I'm looking to upgrade my razor mx500 electric pit bike to lithium and a larger motor. I'm stuck between a 36v 1000w motor and a 48v 1000w motor. They are identical looking my1020 motors, and are a direct fit, I don't want to deal with new mounts. Either way the motor will be overvolted significantly, to 66v lithium and 100a controller. Which motor would give me better performance? The controller is programmable so I can limit actual current to a safe value. Also either motor will be geared to the same top speed, around 20mph. I'm mainly looking for good torque for light trail riding. Which motor would take more power without being damaged?

 

[Dauntless]

I think of tinkering with mine, my first question is what do I want it to do?

The my1020 as I know it is claimed to be 3000rpm at either claimed voltage, I'm really not sure there are two winds. So I wonder if it's actually 2,600rpm (At 800w) at 36v and 3,500rpm (At 1,000w) at 48v. Does that really mean it would be maybe 5,500rpm at 66v?

My first suggestion is to try the stock setup at 48v. There's a TEENAGER who's been marketing an adapter cable to add some RC batteries to them that gets rave reviews for the performance increase without spending hundreds of dollars. The next step is something I'm overdue for trying, the yk43 controller. http://tncscooters.com/index.php?route=product/product&path=41_76&product_id=188 You could try out your 66v on the original motor. If you still want a new motor after that, use the yk43 with the 48v motor. I think you might be happy before you get that far.

 

[rudyauction509]

I'm currently running it on 44v, it's quick but doesn't have the hill climbing torque for the trails I like. The motor is 500w and I'm afraid I'll burn it out at 66v. Both motors I'm looking at claim 1000w at 3000rpm, and have different current ratings. They are the ones sold by monsterscooterparts.com. I know 48v usually means more torque vs 36v but the 36v would spin faster and be geared lower. The motors are the same price so I'll get the one best suited to my needs.

 

[rudyauction509]

In my research I found that the 36v motor on 66v may not handle the centrifugal force, so I'm going to have to use the 48v motor. I'm going to modify it for forced air cooling by opening the holes in the ends and ducting a server fan to blow air through the inside of the motor so I can push 50 amps through a 30 amp motor without overheating it, but which will give me the torque I need for trail riding.

 

[dirkdiggler]

I've got two of these mx500 motorcycles. One I switched the motor to a 80-100 turnigy. Runs on 6s at good speeds, but the motor is unsupported on the sprocket end. So far it has worked great for my kids. I haven't had any issues with it, the chain seems to stay in place. Plenty of torque and should be even better on 12s.
The other I used that 60v controller and kept the stock 36v motor. That ran great for a few months and the neighbor kid smoked the motor riding in the dirt. I wasn't around (except to yell at him after he brought it back smoking!) to see how hard he was riding it. He's a punk so probably abused it. To replace that blown motor I bought the Alibaba express brushless version.

I changed out the motor sprocket to the old one. Now the bike does wheelies on command. Motor fits close to the original. If I were you I would put your money into the Boma motor.

 

[Quinc]

I just picked up another MX650 and looking to mod it. What did you end up going with and how do you like it? Have you looked into the hub motors at all? I am thinking it would be fun to have a hub motor in both front and rear.

 

[Dauntless]

I'm curious about batteries. There's no room. Ueah, lipo would for more in the little space.

I'd like to hear from the OP, maybe Digs could come back too.