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Razor e300 Mods

Hi there, I recently purchased an older e300. It has 2 new 7ah batteries. I wish to use it to commute to work which is approx. 2 miles. There are some hills and I weigh approx. 200 lbs.

I wish to upgrade it to suit my needs with the smallest amount of changes. I was thinking a larger 24V motor (500w??) and maybe a bigger rear sprocket, and bigger batteries. Would I need to change the controller or anything else if I did this.

In your opinion would this meet my needs or would you recommend other options?


Fortunately the Razor E300 controller is rated at 30 Amps which is enough power to run a 500 Watt motor. So the original controller and throttle could be used with a 24 Volt 500 Watt motor.

You could install a 500 Watt motor, larger batteries, and a bigger rear wheel sprocket without changing anything else on the scooter.

The size of the rear wheel sprocket and power of the motor will determine the scooters hill climbing ability. Installing a larger wheel sprocket and a more powerful motor is a sure fire way to get better hill climbing performance.

It is difficult to say exactly what size wheel sprocket will work best for the hills that you need to climb, however if the wheel sprocket that you choose does not provide enough torque to go up the hills that you need to climb, then an even larger wheel sprocket could be installed to lower the gear ratio. And if the wheel sprocket that you choose goes up the hills with ease then a smaller wheel sprocket could be installed to get a higher top end speed from the scooter.

Please let us know if you have any questions.

Thanks. Should these modifications do what I want it to do? I don't mind doing a bit of "kicking" on the big hills. Or should I be considering a bigger motor? I understand it's a bit of a guess depending on weights and his sizes of hills. Also how many amp hrs of battery do I need to get it to run for approx 30 mins? . 500w divided by 24 volts = 21 amps. Does that mean I need 21 amp/hrs of battery to run for an hour? At the moment I have the 2. X 7amp/hr batteries which together at 24 v still give me 7amp/hrs.... Sorry it's a few yrs since school...
Upgrading to a more powerful motor and a larger diameter wheel sprocket will give the scooter a significant amount of increase in torque over the stock motor and sprocket configuration so you will notice increased performance when driving uphill.

In my experience no matter how much power an electric scooter has, I always wish that it had a little more. So if I were to modify an electric scooter, especially for hill climbing, then I would choose the bigger motor and controller.

Battery Amp hour (Ah) ratings are calculated for a 20 hour period of time. So a 21Ah battery will provide 1.05 Amps of power for 20 hours. The capacity of a battery lowers the faster that it is discharged, so the same 21Ah battery will not provide 21 Amps for 1 hour, it will provide fairly close to that though.

Hills drain batteries very fast, so in your case with either a 24 Volt 500 Watt or 1000 Watt motor I would recommend to install 22Ah batteries for a 30 minute ride time. 15Ah batteries would also probably do the job depending on how much of the 30 minute ride time the scooter was traveling uphill. A 500 Watt motor at full throttle will draw less power from the batteries than a 1000 Watt motor at full power will when traveling uphill, so the size of motor that is used will affect the scooters run time.

Please let us know if you have any questions.

Ok thanks. I have been offered another razor motor. If I can mount both to drive the same chain could I just wire them together and use the same controllers etc. Thanks
Yes you could. We have a guide on how to wire one throttle to two controllers on this page:

Please let us know if you have any questions.
I'm wanting to do a similar project, I go 3 miles to town and 1 is steep
downhill, then need to go back up. I don't have a huge need for speed
so I want to change the rear sprocket to maybe 80 teeth?
Then upgrade to the 500w motor, is that a direct bolt in?
I realize I'll need to change the chain to fit the larger sprocket.
And then I'll buy the largest batteries I can find.
What part numbers do you recommend?
I might also want a variable speed throttle as well, PN:


We have not modified a Razor E300 scooter with an 80 tooth wheel sprocket before so I do not know if there would be a clearance issue or not. The E300's original 55 tooth sprocket has a 4-1/2" outside diameter and an 80 tooth sprocket has a 6-1/2" outside diameter, so you could tape a 1" x 1" piece of cardboard on the edge of the existing 55 tooth sprocket and rotate the wheel to see if it hits the frame.

I found a photo of the E300 scooter's rear wheel and frame and it looks like there is plenty of room for a 6-1/2" sprocket, however I would verify that it fits the frame to make sure before ordering the 80 tooth sprocket. This photo also shows a 500 Watt motor with mounting base which is the same size as our MOT-24500X2500B motor that is partially bolted onto the E300 scooter's frame.

Our 500 Watt motors are larger than the Razor E300's original 250 Watt motor is and the sprocket to mounting base holes are different lengths also, so it is not a direct bolt in, as can be seen in the photo above.

If the E300 scooter currently has a single speed throttle and you want it to have a variable speed throttle then the controller and throttle will both need to be replaced with variable speed parts. Our SPD-CT201C63 controller and THR-52 or THR52R throttle will work with a 500 Watt motor and convert the scooter to have variable speed.

Please let us know if you have any questions.

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