I want to go faster.

Moderators: robnewyork, bassiclyLouDog, gameboy

By jgh
My bad, y2k42-2. Wiring is all good, I thought I was finished and what I thought was a tight chain became very loose when I started to ride. I gave up for the night. Do you think I should try a chain tensioner or should I just remove a link or two?
By robnewyork
measure well and remove a link or 2, the chain should be line piano wire since it will stretch over time with that much power.. Im guessing it moved u.. Also , was the shaft 1/2 inch as posted on ebay?
By jgh
Well it's finally complete, the torque was causing the motor to shift a bit. Which was causing the chain to loosen. I added another hose clamps for support and used some strut washers to shim the one side. The thing is moving pretty good, I would say around 30 or so. It's ok off the line, but it moves once it gets going. Stopping takes some time, do you have any suggestions on improving the breaks? Also, the motor was 1/2", the sprocket was tough to get on though. Hopefully I won't have to take it off any time soon. Thanks for your help, this project would have taken twice as long without you. Not sure what's next, I'll browse the posts and see what I come up with.
By robnewyork
Congrats ~30 sounds awesome.. please share pics of the final build!
Im not sure why the sprocket was hard to get on , id say rust would be the only issue..keep the chain tight and motor pinned in place hard.
as for the brakes, make sure theyy are adjusted so theres only a playing card or less space from pad to rotor before hitting the brakes. it sounds like the brakes are biting late
By jgh
I'll post some pics later, I installed the on/off switch in the same location you did. In place of the faux gas cap. Not only does it look good but functionally I think it's an ideal location. I like the head light idea, I'll look for something on eBay. Now I'm waiting on the charger, hopefully that shows up today. I downloaded a GPS/speed app to calculate my speed. I'll update when I get this thing charged.
By robnewyork
jgh wrote:Have you guys tried this throttle, http://www.ebay.com/itm/12v-24v-36v-48v ... 4g&vxp=mtr

Looks like a cool throttle with the voltage readout and two i/o for light's.

Also, have you ever tried those +5 booster packs? Do you notice a difference in speed and torque?

nice throttle, and yes someone has bought similar before.. pretty cool having the combo.. and simple to wire, it will come with the color code im sure.
the +5 kit just gains top speed.. not torque.. If u want more torque u can add the 90 tooth rear sprocket , and cut and drill it to match the bolt pattern of the stock 80 tooth.. if u want more top speed we can go to 60volts as long as u install a voltmeter to monitor the batteries.. yes ive run ur controller at 60 and 72 volts .. ( dont run it at 72 lol
and , IF you want more torque and the same top spped combiine the 90 tooth and the 5th battery for roughly 2 mph gain top speed and a nice amount of acceleration.. The rear sproctet would need to be removed from the bike, and viced together evenly with the 90 tooth.. then using the 80 tooth as a template drill the 4 mounting holes into the 90 tooth.. Actually if the mx500 has the threaded freewheel out back the 90 tooth simply screws in off the top of my head.
anyway china takes 3 weeks for that throttle
By jgh
That link you posted said your shopping cart is empty. How much is the 90 tooth online? I think I'm gonna buy that throttle. Then when I get board of the bike, I'll put another battery and buy that 90 tooth sprocket from you.
By robnewyork
Now that the controller will no longer cut the bike off when the voltage runs low (48v controller cuts out around 42-43v) you will need to keep track of ur actual voltage so as not to kill the batteries.. Now that ur running 65v peak , you will need to stop riding at 55v and the controller will not stop you.. so u need a way to see the voltage
By robnewyork
yes, as long as u have a live feed of the voltage while riiding it works.. that all being said fresh off a charge u can run 15 minutes with the meter off but going any distance etc the meter needs to be on..
By robnewyork
keep in mind that going higher voltage will decrease run time to an extent.. U may wanna see what the run time is as is before going forward. if u ride the mx like i rode mine ( 15 minute blasts around the block then park it ) this wont be a major concern
By robnewyork
lol.. do u think u wanna do 37mph??? all it takes is a 2 dollar gauge and 1 more battery! if the motor is cool at 48v it should be fine at 60
By robnewyork
Yes they make a charger, good call i almost forgot.. U can charge the 5th battery with a car trickle charger if u have one to save money.. if u want it all plug and play ,
http://www.ebay.com/itm/Electric-Bike-6 ... Swqv9V6BJd
http://www.ebay.com/itm/Electric-Bike-6 ... SwrklVRSsV

http://www.ebay.com/itm/Top-Selling-60V ... xy3zNSfiYq

http://www.ebay.com/itm/Electric-Bike-6 ... Swqv9V6BJd
By robnewyork
hmm where to put 5th battery.. id need a pic of how it all sits right now.. maybe in the swing arm where the stock motor used to sit?? i have no idea lol
By jgh
That's a good idea, I'll have to look and take some measurements tomorrow. I'll post some picks also. Also, what is this $2 gauge you speak of?
By jgh
I can't deal with those lengthy ship times from China. I would probably just buy the plug and play option from an American.
By jgh
Should have used black zip ties to make the fastening a bit more conspicuous but it will be covered by the side panels. Just have to figure out how to get that fifth battery in there, not sure if it will fit where the old motor was. Still haven't measured it yet.
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By zen_racer
jgh wrote:Should have used black zip ties to make the fastening a bit more conspicuous but it will be covered by the side panels. Just have to figure out how to get that fifth battery in there, not sure if it will fit where the old motor was. Still haven't measured it yet.

clean work, looking sharp! did you fabricate new side panels?
By jgh
Thanks guys, it has been a fun project. Those are the original shocks and I did have to fabricate almost all of the plastic, including the side panels. Have to figure something out to cover the chain. Haven't come up with anything yet. The controller is mounted in the back above the motor, if you zoom in on the picture you can see it right below the seat. It made it a little tough getting the seat back on but it worked out.
By robnewyork
keep up posted with pics when the rest of the plastics go on.judging by the pic the battery may or may not fit...that controller is huge as i recall, good spot for it hidden from the weather
By jgh
I think there is enough room to mount that 5th battery in the front right behind the front tire. Is that 90 tooth gear you have set up for the mx500? If so I'll take it. Think I'm gonna order that battery, charger and volt meter. This project is getting pricey , my wife is gonna have my balls.
By robnewyork
lol.. i think it should mount to the freewheel on the mx500.. Im not positive but i know the mx500 has a freewheel.. dont forget the 90 tooth will bring ur top speed back down to almost where it is now.. about 32 ish. Also on the 90 u will need to elongate the chain a bit..the new one i linked is dirt cheap and in better shape than mine.. have a look i think its like 16 shipped.if it doesnt fit the threads on freewheel u can chop it and match the bolt pattern on the 80 tooth to mount it (i know the threads match, just a matter if it will spin in the right direction
By jgh
Can you post that link again with the 90 tooth?Nothing showed up last time. So the extra battery and the 90 tooth will just improve my acceleration? You think top speed will remain the same?
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By zen_racer
adding 12v and swapping out to a 90t rear will increase both torque and top speed. just plug in the numbers in a speed calculator and you'll get accurate results:


not sure what motor sprocket you're runnning, is it the 14t? so 80/14 gearing, 4400rpm @ 48v, and 14" wheel top speed is just over 32MPH.

add the 5th batt and change the rear sprocket to 90t, now you're looking at over 36MPH with more torque ...very nice numbers for an MX500!
By jgh
Thanks for the link, I am currently running an 80/14. Time to start running numbers, 36mph is a very nice number.
By robnewyork
now theres one more way to calculate top rpm of the motor , but its often negated by the drag both mechanical and electrical..
if the motor spins at 2200 ideal at ideal 24 v that means 2200/24=91.66 extended
91.66 at peak 65v =5958 rpm max from the motor
when we calculate 5958 into the equation we get 38.601 MPH top speed.
But again we have to factor drag coefficiency so you may get 33-34 mph , no way to tell without testing.. Now with the stock 80 tooth rear the hypothetical top speed would be
43.43 mph , or roughly 38 mph real world..

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