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Razor Quad motor upgrade to 36v - parts question

I have converted the quad to 36v via battery and controller parts but we keep burning through motors. I put together a parts list and was wanting to know if everything looks compatible and if it will likely solve the problem. The only other question is whether or not to do the 65 tooth rear sprocket at a lower top speed or the 55 tooth one with a higher top speed. The quad is used extensively off road and going up hills. Here is the list (any suggestions on changing any parts including the motor are welcome too):


Item # SPR-2509C - 9 Tooth 10mm Double D-Bore Sprocket for #25 Chain

Item # MOT-36500X2500B - 36 Volt 500 Watt 2500 RPM Motor

Item # SPR-2565S - 65 Tooth Rear Wheel Sprocket for #25 Chain

OR Item # SPR-2555 - 55 Tooth Rear Wheel Sprocket for #25 Chain

Item# CHN-HD2560 - 60 Links Of Heavy Duty #25 Chain With Master Link - 15"

Item# CHN-HD25HL - Heavy-Duty #25 Chain Half Link


Thanks in advance!!


More details: Main rider is 35lbs but sometimes a 110lb rider as well. Very hot climate (95-105 degrees F in summer).

Just to be clear, the stock quad simply overvolted to 36v is fine in regards to speed and climbing ability (it could even be a mph or 2 slower and it would be fine). It is not that I need "more", I just need the motor to not burn up after a few weeks. Another detail is that a 2-3 hour ride once a week is not out of the ordinary at all.

We ran a gear ratio and top speed calculation using those parts and got a 13.43 MPH top speed with the 65 tooth sprocket and a 15.87 MPG top speed with the 55 tooth sprocket.



We feel that with a 35-pound rider both of these gear ratios will be okay for off road and going up hills that the overvolted motor is currently accomplishing. Whether they will be okay with a 110-pound rider going up hills depends on the degree of incline that the hill is. The larger the axle sprocket is the better the motor will do when going up hills with heavier loads. 


All of the parts in your list are compatible with each other. The only thing we are not sure about is the chain length because that can't really be determined until the new motor and sprockets are installed. You could always get what you think is more chain than needed and then break it down to the right size after installing the new motor and sprockets. 


Please let us know if you have any questions. 

I know you can't guarantee anything but it this setup (with the 65 tooth rear sprocket) something you'd feel fairly confident would last a while? Or would you recommend a bigger motor (i.e. the 36v 1000 watt one)? Or is motor wattage not really the determining factor here? 


FYI, I have 3 22ah batteries installed so the extra juice a 1000 watt motor would use isn't really much of an issue (it lasts 6+ hours now with the stock motor easily and it will never be ridden more than 2-3 hours without a charge).

The setup with 500 Watt motor and 65 tooth axle sprocket should last a very long time as long as the motor is not overheated. I do not feel that a 35-pound rider would overheat the 500 Watt motor under the riding conditions which you described but am not sure how the motor would be with a 110-pound rider going up steep hills. With a heavier load, the motor may run cool or may run hot depending on the steepness of the hill and how long the hill is. 


Installing a 1000 Watt motor would provide twice the amount of torque and power as a 500 Watt motor which would significantly reduce the temperature of the motor with heavier loads going up hills. A 500, 750, or 1000 Watt motor will proportionally consume as much power as it creates so with a relatively slow top speed such as 13.43 or 15.87 MPH its power consumption and drain on the battery pack will be low except when going up hills. 


As long as the hills are not too steep and too long then the 500 Watt motor should be fine, however, if the hills are very steep and very long then a 750 or 1000 Watt motor may be a better choice. 


Regarding the 36 Volt 1000 Watt motor with mounting base, it is currently sold out, however, it will be back in stock in around 3-4 weeks. We currently have the 36 Volt 500 and 36 Volt 750 Watt motors with mounting bases in stock. 


Please let us know if you have any questions. 

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