Razor MX650 electric dirt bike build

[Quinc]

Picked one of these up a couple years ago and use it so much it is on its second set of batteries. So picked up a great deal on a brand new one for the family and going to upgrade my older one to make it more adult/camping friendly goal is enough torque to be able to climb some decent dirt trails.

First mod - added a drink holder for my beer

Second - changed out the motor sprocket from 11t to 9t.

Third - swapped out the rear shock for a pitbike shock and raised the rear up a couple inches.

Forth - is going to 48v

Fifth - will be to pick up a 48v 1800w brushless setup whenever ebay has another 15-20% off coupon

Six - mod if the torque still sucks will be to get a rebel gears 92T or 100T rear sprocket.


On the maybe list:
Handlebars
crf50 tall seat
wider rear tire

 

[sikbrik]

Cool...I keep thinking about grabbing one of these off of Craigslist. They come and go pretty regularly for not too much money.

 

[voided]

My 48v brushless setup pulls me around easily (275lbs) at 23mph ... it’s what it’s geared for.. if you think your gonna want more power I’d say look into the newer 60v one they are making..

 

[Quinc]

Also considering going dual hub motors and turning her into a climbing monster. Just have to find some that fit.

 

[Panhead5496]

Following! Can't wait to see this build.

 

[Quinc]

Got the 4 batteries mounted. I like the idea of the 60v 2000w motor but not sure how I would fit a 5th battery and still keep it looking stockish.

The mx has been getting slower and only lasting a mile or two vs the 10 miles they are supposed to last. So after replacing the batteries and checking the batteries multiple times I took the motor apart. And the bearing the shaft rides in was completly rusted. So cleaned up the motor with a scuff pad and starting fluid and order new bearings.

 

[voided]

Can you rearrange the batteries? Maybe stack them?

 

[Quinc]

Can you rearrange the batteries? Maybe stack them?

I think I would have to drop down to 9 or 10ah vs the 12ah-15ah batteries to get them to fit and still put on the side covers?

---------- Post added at 05:16 PM ---------- Previous post was at 05:14 PM ----------

Cool...I keep thinking about grabbing one of these off of Craigslist. They come and go pretty regularly for not too much money.

Get one! Probably enjoy this with the fam kids and neighbors more then any other toy. And everyone who rides it has an ear to ear smile.

 

[Quinc]

Batteries mounted and wired with 10ga.
Soldered the charging plug directly to the battery. Bought a cheap 48v charger and going to cut the end off and solder on the original plug. And what the motor shaft bearings looks like.

Ordered an lcd volt gauge as well to hopefully keep me from over discharging the batteries. At least until I get a 48v controller. *The black tape is to keep the plugs from coming apart. All connections are also covered in di-electrical grease.

 

[Functional Artist]

Lookin' good

Did ya include a fuse in your charge plug circuit?

 

[Quinc]

Lookin' good

Did ya include a fuse in your charge plug circuit?

Good catch and good idea! I normally run a 100-200amp circuit breaker for the whole system. But I will add a little fuse directly to the charge port.

 

[Quinc]

Fuse added! and wired it in near the back of the frame so I can get to it without taking apart the plastics.

Took off the dust shields on the new bearing and packed with quality high temp grease. (seems to make these cheap Chinese bearings last longer)

Got the motor mounted and realized the chain had a tweaked link in it, so made a new chain with some spare I had.

Cut the side plastics to fit the forth battery. Then the yellow fenders cover the battery so it is out of site.

Power still leaves a lot to be desired so will be getting the Chinese 1800w motor setup next for her.

Picture is of a 100% stock one and the one I just finished. You can see the height difference by comparing the rear fender height off the back tire.

 

[Functional Artist]

Fuse added! and wired it in near the back of the frame so I can get to it without taking apart the plastics.

Took off the dust shields on the new bearing and packed with quality high temp grease. (seems to make these cheap Chinese bearings last longer)

Got the motor mounted and realized the chain had a tweaked link in it, so made a new chain with some spare I had.

Cut the side plastics to fit the forth battery. Then the yellow fenders cover the battery so it is out of site.

Power still leaves a lot to be desired so will be getting the Chinese 1800w motor setup next for her.

Picture is of a 100% stock one and the one I just finished. You can see the height difference by comparing the rear fender height off the back tire.

Looks great, good job!

If your are gonna go for a bigger motor maybe look into skipping the chain & looking into them new hub style motors.

Here are a few examples
...but, your probably gonna want to go bigger than these

https://www.ebay.com/itm/Ebike-One-...518?_trksid=p2349526.m4383.l4275.c10#viTabs_0

https://www.ebay.com/itm/Electric-B...m=253648291133&_trksid=p2047675.c100009.m1982

 

[Quinc]

Looks great, good job!

If your are gonna go for a bigger motor maybe look into skipping the chain & looking into them new hub style motors.

Here are a few examples
...but, your probably gonna want to go bigger than these

https://www.ebay.com/itm/Ebike-One-...518?_trksid=p2349526.m4383.l4275.c10#viTabs_0

https://www.ebay.com/itm/Electric-B...m=253648291133&_trksid=p2047675.c100009.m1982

This was my original plan after seeing a guy doing wheelies with a 3000w rear hub motor. then I thought it would be cool to do one on the front and back wheel. But then it came down to I already have way too much money into these electric toys for how much use they get.


Any of you guys use "Heavy Duty" #25 chain? Considering going to #35 when I upgrade to the boma. Rebel gears charges the same 50$ rather you go with #25 or #35 chain as well.

 

[Quinc]

Boma 1800w on its way! 79$ shipped with controller twist throttle and foot throttle.

 

[sikbrik]

That's quite a deal!

 

[Quinc]

That's quite a deal!

Almost seems too good of a deal. So not getting my hopes up to high. Also the motor is labeled as a boma my1020 so that would be cool to if it is a legit Boma.

 

[Panhead5496]

Do you have the link? I know it's sold out but curious.

 

[Quinc]

And picked up one of these for the kids.. Wife is probably going to throw me an intervention soon.. Once I finish soldering the connections and mounting 6S lipos I will get some video. I also have a 350w motor on the shelf roughly the same size that it will be getting next. (stock is 150w)

 

[sikbrik]

That minimoto is cool! Keep having fun til the intervention