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Razor dirt quad 24v needs more speed!

Hello I have a boy and a girl. The boy rides the razor MX300 Dirtbike and the girl rides the dirt quad. I ride my Bicycle with them on paved trails and the dirt quad is too slow. Is there a rear sprocket I could change out to get us more TopSpeed from the dirt quad. We don't need the extra torque to go off-road. I wouldn't mind getting a couple miles an hour out of the dirt bike either but the dirt quad needs the biggest boost in speed. What do I need to do to get the dirt quad over 15 miles an hour for the cheapest way possible? Veraval speed on the dirt quad would be great so the chances of flipping over while turning would be less likely
The Razor Dirt Quad has a 25 tooth motor sprocket, a 47 tooth rear axle sprocket, and 8mm chain. To increase the gear ratio for a faster top speed a smaller rear sprocket could be installed. We have 44 tooth, 38 tooth, and 36 tooth rear axle sprockets that fit the Dirt Quad.

Here are the gear ratios and top speeds with the stock 47 tooth sprocket, and also with a 44, 38, and 36 tooth sprocket.


The most that the speed could be increased using 8mm chain sprockets is by 3 MPH for a top speed of 13 MPH.

The MX350 has a top speed of 14 MPH so it would still be 1 MPH slower than it but it will be a lot closer to being the same speed than when it ran at 10 MPH.

The 25 tooth sprocket for 8mm chain on the Dirt Quad's motor is the only size 8mm chain sprocket that is available for that motor.

We do have sprockets for 1/2" x 1/8" bicycle chain that fit the Dirt Quad's motor however I ran a gear ratio calculation with the largest motor sprocket and smallest axle sprocket available for this chain size and only got a top speed of 10 MPH.


The Dirt Quad's stock chain has 74 links. If a 36 tooth sprocket is installed then a 68 link chain will be needed.

Here are chain size calculations for the original 47 tooth sprocket and a 36 tooth sprocket.


We sell the item # SPR-836F 36 tooth sprocket for 8mm chain on this page:

We sell item # CHN-800 8mm chain sold by the link and item # CHN-8ML 8mm chain master links on this page:

Please let us know if you have any questions.

So if I order the 36 tooth rear sprocket I need a 67 link chain plus the master link to make a total length of 68 links? Do you guys offer a variable speed controller? I found one online from a competitor of yours that claims It can give the motor 25-26v at full throttle and will add a couple miles per hour plus it's variable speed.  Do you have a controller that can match a claim? Is that claim even accurate?
The master link is not included in the chain size calculation because it is not considered to be part of the chain, so a 68 link chain plus a master link should be ordered.

All Razor Dirt Quad controllers are variable speed. Both the version 1-10 and 11+ controllers that we sell for the Dirt Quad are variable speed and they both have a 30 Amp maximum current output rating which is suitable for motor up to 500 Watts.

I have never tested the output Voltage of the original controller and compared it to a different controller so I can not confirm a claim that a different controller outputs more Voltage than the original controller.

I can tell by looking at the competitors controller that it is made by the same factory that makes our item # SPD-CT201C63 controller for the Dirt Quad version 1-10. This factory does not make 24 Volt controllers rated over 30 Amps so both of our controllers will have the same power ratings if they purchased the 30 Amp version of it.

One difference between our SPD-CT201C63 controller and their controller is that our controller works with the original version 1-10 throttle, and we had the factory custom make our controllers with the right connectors factory installed on them instead of us cutting the connectors off of a standard controller and soldering new connectors back onto it to fit the Dirt Quad.

We will not match any competitors claims however we can sell you the same controller that they are selling which is our item # SPD-CT201C63. This controller will work on version 1-10 using its original throttle, and will work on version 11+ if a version 1-10 THR-52 or THR-52R throttle is installed along with it.

Please let us know if you have any questions.
So I'm think you don't think or don't know if the competitors or your own speed controller would produce any gains with my quad. They are Basically the same as the stock one. Do you guys sell a 36v overvolt kit for my dirt quad? The competitor has one for $109 With a battery and a new controller a new charger and wire harness.
We would not sell a kit like that $109 one because adding a new battery to a used battery pack and mixing different ages and brands of batteries together is something that we strongly advise against. If a battery pack was made with different ages and brands of batteries then the Voltages of the individual batteries in the pack would become continuously more unbalanced as the battery pack was being discharged and recharged, which would cause some of the batteries to be overcharged and others to be undercharged. Overcharging and undercharging batteries damages them and significantly lowers their lifespan. We recommend to only make battery packs from batteries that are the same age and same brand.

We do not have a 36 Volt overvolt kit for the Dirt Quad yet, however we do have 36 Volt plug-and-play controllers available for the Dirt Quad which are item # SPD-CT312C1 for version 1-10, and item # SPD-CT312C1-6 for version 11+. These controllers work with the original throttles and plug directly into all of the Dirt Quad's existing wire connectors. With these controllers the only other major parts that would be needed are a 36 Volt battery charger such as out item # CHR-36V1.6A3P, and a set of three 12 Volt 8ah or 12 Volt 9Ah batteries.

The existing battery pack wiring harness could be reused on the new batteries by cutting the wires off of the old batteries and installing 1/4" tab terminal crimp connectors onto the ends of its wires. The third battery could be wired in between the two batteries in the battery box with long jumper wires to reach it since it will be outside of the battery box. Here is a drawing showing how to wire the battery pack this way.


The blue and green wires in the drawing are only those colors to make them easy to see. These blue and green wires could be a different color such as black so they would blend in better with the ATV and not be so visible.

We could make the wiring harness in this drawing and include it with a kit made from the parts mentioned above if you are interested in buying a Razor Dirt Quad overvolt kit like that?
The chain and sprocket worked out perfectly. I got a 67 link plus the master and was able to remove the loud chain tensioner. I would guess at least 30% fast top end It worked out great thanks.
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I'll try to post another video but just know it was worth it
Great to hear that the smaller sprocket and chain solved the slow speed problem. Thanks for letting us know that it worked and also thanks for attaching the photos and video.
17.2 MPH It's now a 36 razor. New battery and controller
36 overvolted

Awesome, the Dirt Quad looks plenty fast now. That's a nice park that you have to ride it in. Thanks for sharing the videos.

I just ordered one of these and awaiting on shipment. Just wondering could I use 2 agm batteries to extend riding time? I know I put one on a John Deere power wheel and it would ride for at least a week before it needed charging, not that it was close to giving in only slowing down. I charged it manually on a trickle charger. Thanks for any help in advance and sorry to intrude not his forum, didn't know who to ask or where
These are batteries from a hover round power chair if that makes any difference.

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