Instructables

how to speed up, get longer range on your Razor MX500-MX650 Dirt Rocket Electric Motocross Bike??

 battery upgrades?, power adjustments?

Picture of how to speed up, get longer range on your Razor  MX500-MX650 Dirt Rocket Electric Motocross Bike??
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PaulS31 month ago

I just added a 4th battery and I see a considerable difference, Is there any way I can change the 11 tooth sprocket to a 16 tooth sproket, that will give me a lot more top speed. please advise...and where can i get one.

-DOUG-2 years ago
You can overclock the motor by going over 36 volts with the batteries If you simply add a new battery to the 3 old ones, they have a way of buring out quick, so you want all new. Longer range just means either/or more batteries and/or larger amperage batteries. You will have to figure out where to put an additional battery, larger batteries, etc. This could cost over $100, over $200, etc., depending how you go. You'll need a new 48volt charger, too. Might be $45 with the shipping.

The problem with the controller/esc is that it might not simply pass the additional electricity through. I have 3 of those things but haven't tried to hop them up. With the CurrieTech scooters there's an exposed archwire in the esc that you layer some solder on it and it'll carry more juice, I don't know if this will work with the Razor. The MX500 and the MX650 use the same esc, so the 650watt motor would work just fine if it replaced the 500watt. Whether you can successfully overclock either motor without replacing the esc I can't say, but a new controller of sufficient capacity can be had under $100 including the shipping.

If you put a smaller sprocket on the back, haven't seen prices maybe $25 with shipping, you have to take links out of the chain with a $20 breaker, or you put a pinion in front , maybe $25, with one more tooth without touching the chain, either will make it faster top end but not as quick responding. I recommend this to coincidence with the power upgrade, but not without it.

If you spend maybe $250 with shippig for a new 1,000watt 48volt motor and a 1,000watt, 48volt/20amp controller, you get results. If you go brushless for more money, you get better results. Either way you might have some figuring to do over mounting that motor properly. You still need the charger, etc. Face it, this is expensive.

Oh, hey, aren't we getting up close to the cost of something new? When I played with my CurrieTech and turned the near useless 350watt into maybe a 450-500watt, it cost the replacement of the bad battieries, use of a different charger I had, a small amount of work, meaning a cost of not much. Improvement, not much. What you're wanting to do might cost what you paid for that new. If you've rode both the MX500 and the MX650, you realize that you barely notice a difference. I want to say you won't get the results worth what you'll spend.

Unfortunately, there's a gap in the market where the 650watt Razor leaves up and the more powerful big bike pick up. If Razor or someone else with these smaller bikes offered a companion bike at 1,000watts with slightly larger wheels there would probably be quite a market, but noone is offering one.

Maybe if you could find a suitably sized Honda or Yamaha or Chinese bike, CRF80 etc., with a hammered piston in the 2 cycle engine you could pick it up cheap, someone would buy the engine for parts, you put a 1,000watt or larger motor on there, everyone is happy. You might even be content doing this with a BMX bike that is dual suspension, such as those XGames bikes you could have used for $50.
Re-design4 years ago
You need to get more capacity in the batteries to get more range.  You might change the gearing but that will reduce the accleration and may actually cause a reduction in distance traveled on a charge.  If you can replace the motor with one that is more efficient you would get more range.