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Razor mx500 (mildly modded monster)
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Discussion Starter · #61 ·
Electric scooter parts dot com sells both sprockets. Can get a 9 10 11 or 12T for the motor, and the rear the biggest is a 72T, and then a 64T
It's funny you mentioned sprockets because as it turns out I came across an imod scooter for 20 bucks and turns out they have a larger rear sprocket than the mx line, so I retrofitted it to an mx650 I came across (the one in borrowing the chain from currently) and ordered a new chain so hopefully it fits, would be cool to see how much it helps torque on the stock mx650! Pretty sure it's a 72 tooth but I haven't counted yet.
 

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Discussion Starter · #62 ·
I just counted and it's an 88 tooth rear that came off the imod... I had to count it twice to be sure my eyes weren't deceiving me!
 

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Discussion Starter · #64 ·
Yeah for sure! If it yields expected torque gains without sacrificing too much top end this could spark a pocket mod sprocket swap trend hahahaha!
 

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Discussion Starter · #65 ·
And I think it looks way cooler too
160910
 

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Yeah for sure! If it yields expected torque gains without sacrificing too much top end this could spark a pocket mod sprocket swap trend hahahaha!
I have seen threads where people have gone one tooth smaller in the front or six teeth bigger in the rear and have gotten both an increase in top speed and more torque and more run time seems the stock gear ratio is meant for a 65 lb Rider
 

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Discussion Starter · #67 ·
I have seen threads where people have gone one tooth smaller in the front or six teeth bigger in the rear and have gotten both an increase in top speed and more torque and more run time seems the stock gear ratio is meant for a 65 lb Rider
How interesting! Well now I'm really excited to see how it pans out!
 

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What's your poison? Mine is 40:1
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My buddies lithium 24 volt 500 watt has stock gearing, we're going to put a bigger one on the front to see if we can hit 30, then back it off one tooth to a 10T. Should be interesting.
 

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Discussion Starter · #69 ·
My buddies lithium 24 volt 500 watt has stock gearing, we're going to put a bigger one on the front to see if we can hit 30, then back it off one tooth to a 10T. Should be interesting.
How's the torque on that? Is it comparable to overvolting a 36v 500w to 48v? I know the top end is there but I'm curious about the low end...
 

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So much better than stock. Plenty of takeoff but I'm sure you're 48 volt has more. Every time you jump 12 more volts, things just get more crazy. LOL.
With the stock gearing and overvolted 24 volt motor, it climbs Hills, it'll go through grass easy etc. My son has a mototec 36 volt 1000w bike, stock setup, geared really low. That thing takes me through grass like nothing better than the mx500. Top speed is geared for about 18 with me on it and 19 with my kid.
 

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Amps are what give you torque.
Voltage is what gives RPM

These types of electric motors are lacking RPM and not torque the reason why they lack torque in the stock form is simply because the SLA battery Bank cannot provide enough amps to feed the motor

On take off they can draw up to 30 burst amps is why I recommend a 50 amp BMS a 30 amp BMS will only provide about 25 amps before it starts having problems.
 

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Discussion Starter · #72 ·
Good to know! I wasn't sure exactly how that all panned out in laymen terms but it makes sense now and kinda makes me want to build a 36v system with 24v 500w motor and modded speed controller just to compare it to my build
 

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Good to know! I wasn't sure exactly how that all panned out in laymen terms but it makes sense now and kinda makes me want to build a 36v system with 24v 500w motor and modded speed controller just to compare it to my build
Definitely want to see the comparison.
 

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Amps are what give you torque.
Voltage is what gives RPM

These types of electric motors are lacking RPM and not torque the reason why they lack torque in the stock form is simply because the SLA battery Bank cannot provide enough amps to feed the motor

On take off they can draw up to 30 burst amps is why I recommend a 50 amp BMS a 30 amp BMS will only provide about 25 amps before it starts having problems.
Proof was with my buddies overvolted 24 volt 500 watt started life as SLA and the 12ah just would not allow more than a quarter throttle before it chattered. Then we installed a 10 amp hour lithium, plenty of juice. But that motor keeps pulling more than 30 amps, he keeps blowing the fuse after every third or fourth ride. The BMS is is a regular discharge at 25A, maximum instant is 40A. Gonna install breaker. But it really needs a bigger battery.
 

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Discussion Starter · #75 ·
Proof was with my buddies overvolted 24 volt 500 watt started life as SLA and the 12ah just would not allow more than a quarter throttle before it chattered. Then we installed a 10 amp hour lithium, plenty of juice. But that motor keeps pulling more than 30 amps, he keeps blowing the fuse after every third or fourth ride. The BMS is is a regular discharge at 25A, maximum instant is 40A. Gonna install breaker. But it really needs a bigger battery.
Yeah those lower amp hour batteries seem to come with lower bms ratings for some reason... kind of a buzzkill
 

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Proof was with my buddies overvolted 24 volt 500 watt started life as SLA and the 12ah just would not allow more than a quarter throttle before it chattered. Then we installed a 10 amp hour lithium, plenty of juice. But that motor keeps pulling more than 30 amps, he keeps blowing the fuse after every third or fourth ride. The BMS is is a regular discharge at 25A, maximum instant is 40A. Gonna install breaker. But it really needs a bigger battery.
The individual cells have a C rateing which directly correlates to their amperage discharge rate cheaper cells have a lower discharge rate you're ready made battery packs have a BMS to match the cells discharge rate and prevent them from being discharged too quickly causing them to vent most smaller packs don't have cells lined up in series parallel they just have them lined up in series for voltage for this reason you will need to purchase cells that have a higher C rating because you have less rows of cells...

Go with Panasonic 18650 cells they are the same as the ones they use in the Tesla cars and have a much higher individual discharge C rating then the Chinese no name junk cells then you can use a BMS with a higher amperage discharge rate.

If you find yourself tripping the BMS or close to tripping the BMS in ready-made packs eventually you definitely will have a fire ( hoverboard style )
 

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Yeah I know Panasonic cells are really good, but unfortunately I am probably never ever going to build my own pack. I just don't have the time. This pack works really good for my buddy's bike, 40/25 I thought was really good for a 36 volt 10 amp hour battery. I've seen 36 volt 14 amp hour batteries with 30 / 15 discharge. As long as I know I'm buying 18650 cells we'll be good, his pack is 10 series 4 parallel.
I bought hoverboard packs that I hook in parallel a Razor Pocket Bike, or overvolted and running 24mph with a 47T rear sprocket. Not as impressive as I wanted but the lithium packs alone at at 3 mph. The lead acids just were not keeping up at all.
For stock rebuilds that I flip I will use lead acids but otherwise lithium for everything else.
So far I've been enjoying the pre-made packs. Even if some crazy reason they only last one year, it was well worth the money over lead acids for run time and ease charging.
But I'm sure two or three years will be a pretty good assessment. That 10ah on my buddies is over a year old already.
 

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Discussion Starter · #78 ·
The individual cells have a C rateing which directly correlates to their amperage discharge rate cheaper cells have a lower discharge rate you're ready made battery packs have a BMS to match the cells discharge rate and prevent them from being discharged too quickly causing them to vent most smaller packs don't have cells lined up in series parallel they just have them lined up in series for voltage for this reason you will need to purchase cells that have a higher C rating because you have less rows of cells...

Go with Panasonic 18650 cells they are the same as the ones they use in the Tesla cars and have a much higher individual discharge C rating then the Chinese no name junk cells then you can use a BMS with a higher amperage discharge rate.

If you find yourself tripping the BMS or close to tripping the BMS in ready-made packs eventually you definitely will have a fire ( hoverboard style )
You sir, are a trove of knowledge!
 

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Discussion Starter · #79 ·
The chain came in so I was able to try out the 88 tooth rear sprocket on the stock 650... and while it's nothing to write home about I did notice it doesnt seem to work as hard going up hills or accelerating, so that's good. If the customer goes through with the overvolting and speed controller modding like we've discussed then it'll be a torque beast for sure!
 

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Yeah I know Panasonic cells are really good, but unfortunately I am probably never ever going to build my own pack. I just don't have the time. This pack works really good for my buddy's bike, 40/25 I thought was really good for a 36 volt 10 amp hour battery. I've seen 36 volt 14 amp hour batteries with 30 / 15 discharge. As long as I know I'm buying 18650 cells we'll be good, his pack is 10 series 4 parallel.
I bought hoverboard packs that I hook in parallel a Razor Pocket Bike, or overvolted and running 24mph with a 47T rear sprocket. Not as impressive as I wanted but the lithium packs alone at at 3 mph. The lead acids just were not keeping up at all.
For stock rebuilds that I flip I will use lead acids but otherwise lithium for everything else.
So far I've been enjoying the pre-made packs. Even if some crazy reason they only last one year, it was well worth the money over lead acids for run time and ease charging.
But I'm sure two or three years will be a pretty good assessment. That 10ah on my buddies is over a year old already.
Right on and I agree time money longevity and safety all play a part in the LI ion game as long as you know what you have and know how to treat it ( for instance charging safety ) it's all cool and I have even disassembled multiple Chinese packs used my RC car charger to find the bad cells and rebuilt packs revitalize them and use them for years...

But those packs also get charged inside of a metal garbage can well I'm around to stop the charger if something starts going wrong.

I have personally had fires cell venting puffing connector leads melting off and all kinds of nasty stuff happened because of using old bad cells but it is what it is you know 🤔😀
 
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