The most expensive Motoped

HCx

1 mW
Joined
Jan 24, 2020
Messages
16
So, A few years ago I picked up a Motoped and it was great. Lighter and more nimble than a dirtbike with capabilities that better matched my riding style instead of the bus jumping monsters current dirtbikes are.

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The problem was that gas motor was always being fiddly, wanting adjustment, making a mess. had to go.

The first thing to do was figure out the electric powertrain. What I settled on was the following:

Motor: Sur-Ron light bee
Controller: Nucular 24F
Throttle: Domino
Batteries: Molicel P42A 20S8P configuration
BMS: Smart ANT 180A cont/450A peak (not in love with it, but I can't seem to find what I feel is a better option right now. Suggestions?)


The first mockups for the frame design looked promising, but the old frame brought alot of weight to equation (15lbs) and was getting in the way of my pack placement.

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So it was time for a more dramatic redesign

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Alot of work was done to narrow the bike. Right now i'm looking at a total width between the imaginary footpegs of 6.6"

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And if you're going to do a job like this you need a machine to help get the job done.


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Right now everything is onhand except for the pile of aluminum required to make the main frame.

If something looks stupid with my battery pack design let me know. Right now i'm planning on having a 12 ga wire between each series run all coming together (a total of 4 positive wires, 4 negative wires) into the BMS and then out to the controller. My hope is this will keep the pack balanced because I'm aiming to pull 250+ amps from the pack and/or max out the Nucular 24F/Motor
 
I don't see how those excessively large wires to the BMS Will help the pack stay balanced.

All you need to do is to use new cells and ensure adequate series connections and of course a balancing BMS of decent quality.

Otherwise it looks good.
 
AWG 12 = 3,3mm² >>>>4x3,3= 13,4mm² for up to 250A is not too big.

If you want more balancing power >>> JK-BMS with 2A active balancer.
 
2A is a high actual balance current, even for 180Ah cells

Balance leads to a BMS are often AWG #16 or thinner. These are not used for pack level power, just balancing and measuring per-group voltages.

HCx said:
Batteries: Molicel P42A 20S8P configuration
...
i'm planning on having a 12 ga wire between each series run all coming together (a total of 4 positive wires, 4 negative wires) into the BMS and then out to the controller.

There should just be one series string, connecting 8-cell groups in parallel, a single power pair to handle the high current flow, which has nothing to do with the 21 balancing wires.

 
john61ct said:
2A is a high actual balance current, even for 180Ah cells

Balance leads to a BMS are often AWG #16 or thinner. These are not used for pack level power, just balancing and measuring per-group voltages.

HCx said:
Batteries: Molicel P42A 20S8P configuration
...
i'm planning on having a 12 ga wire between each series run all coming together (a total of 4 positive wires, 4 negative wires) into the BMS and then out to the controller.

There should just be one series string, connecting 8-cell groups in parallel, a single power pair to handle the high current flow, which has nothing to do with the 21 balancing wires.

I suspect I misspoke when talking about the BMS.

The balancing lead connections will be 18ga.

I'll be using 4 12ga wires on the end of each series run to parallel the pack as shown in the picture.

bms connection.PNG

This is just for where I plan on pulling amperage to run the motor, not for balancing.

The cells are all brand new so I hope everything is well balanced from the get go because I don't plan on voltage balancing 160 individual cells.
 
SlowCo said:
Nice project.
But probably easier to fabricate a pedal drive unit on a Sur-Ron :wink:

I'm dropping the pedal drive unit. Will be hard to convince anyone this is a Pedal assist bike when I'm done.

And yeah a Sur-Ron would certainly be easier, but what's the fun in that?
 
Bit of progress over the weekend.

Little gear

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Still using an HTD 8mm belt like the Sur ron has, but wider at 20mm. Hoping between that and my tensioner wrapping around more of the little gear i'll be able to adequately prevent slippage. If not I guess i'll be back making wider gears.

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Big gear came out great as well.

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ATTACH]
 
Nfyerzeva said:

Nfyerzeva said:
That speciific bike is about 13 grand its also (mototec) copy or remake I'm not sure

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Anyway! Lots of progress over the weekend!

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Forgive the washers and missing bolts. Didn't have hardware on hand.

Probably should make a cover over the front belt drive. Looks ready to chew up shoe laces, fingers, small children...
 

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