Full Suspension Leaf Bike 1500W Build

[n00b]

Yeah, the smallest size I can find is 4AWG, and my discharge wires are 8AWG. Thanks for the rec on XT150 connectors! The ones on Amazon say 70-150A, so that will probably work for me.

Oman, what is that stuff I use?
It's 220 wire and comes in green, white, and black, which translates to green, yellow, and blue respectively.
I think there's a red one too, that's just extra for now. It's 10 AWG. Should handle most things one would hook up to a bicycle.
XT90 anti-spark connectors is something you might like.
I would not be afraid to run 108v and 50 amps through that wire at all.
Some over-engineering is OK, but don't go all German with it.
Wire like that would handle more than would burn up your motor, easily, without getting hot.

 

[GoFastGus]

Oman, what is that stuff I use?
It's 220 wire and comes in green, white, and black, which translates to green, yellow, and blue respectively.
I think there's a red one too, that's just extra for now. It's 10 AWG. Should handle most things one would hook up to a bicycle.

If you remember what it is, feel free to drop a pic or a link to it. 10AWG would be too small for my power wires, but might work for my phase wires. I need to do more reading about wire thickness, material & resistance.

XT90 anti-spark connectors is something you might like.

To be clear, I'm gonna use another XT90S connector to connect my battery and controller to start off with, no changing the battery side connector required. After a while, I'll swap to XT150 connectors if I feel like I need to. I'm nervous about soldering on new connectors to a battery that doesn't have a physical or digital off switch. I'm gonna reach out to BMW to see what their recommendation is when the time comes.

I would not be afraid to run 108v and 50 amps through that wire at all.

I'm looking to run 2/3 of that voltage and double that amperage. How would you feel about that?

 

[n00b]

If you remember what it is, feel free to drop a pic or a link to it. 10AWG would be too small for my power wires, but might work for my phase wires. I need to do more reading about wire thickness, material & resistance.

To be clear, I'm gonna use another XT90S connector to connect my battery and controller to start off with, no changing the battery side connector required. After a while, I'll swap to XT150 connectors if I feel like I need to. I'm nervous about soldering on new connectors to a battery that doesn't have a physical or digital off switch. I'm gonna reach out to BMW to see what their recommendation is when the time comes.

I'm looking to run 2/3 of that voltage and double that amperage. How would you feel about that?

You'll fry that motor. That would be my guess. Something will melt.
You might can pull a truck, though.
Be sure and have good torque arms.
I don't think you're going to go that fast.
Here's the wire:

https://www.lowes.com/pd/Southwire-10-AWG-3-Black-Power-Cord-By-the-Foot/50148254

It comes in 8, too.

https://www.lowes.com/pd/Southwire-100-ft-8-awg-4-Black-Soow-Power-Cord-By-the-foot/5004687115

It's for the phases, not whatever you're talking about, but it probably could work for that, too.
It says only 30 Amps, but 600 volts. This is what they hook to industrial machines. It'll take more e-bike-type amps..
to an extent. That's 18 thousand watts the wire can take. Aren't watts a measure of heat?
Okay, so you say you want 100A and let's just say 84v. That's 8400w, less than 1/2 of 18,000.
Would definitely make for a fast ebike, but is it feasible? Seems like a ton of unnecessary heat dumping to me.
You probably won't go any faster, would be my guess. 41 mph, I'd say. If you can stay on it and don't strip your dropouts.

Voltage​

600-volts

35-50 Amps is plenty for a motor like that. Start thinking about your torque arms, especially if the frame is aluminum.
For the kind of fast-taking-offings you seem to want to do, probably need 2 serious torque arms. Like ones that double-clamp
to the seatstay or chainstay and have leverage. Big fun if you get a flat. You'll want to try to make sure you don't.
Quick Drumlin tires are good. With heavy tubes.

 

[99t4]

To be clear, I'm gonna use another XT90S connector to connect my battery and controller to start off with, no changing the battery side connector required. After a while, I'll swap to XT150 connectors if I feel like I need to.

Good plan. Genuine XT90 are rated for 90A. Let's review your specs:

Battery's here, and it fits in the bike frame. 20S4P Molicel P50B cells, JBD 100A continuous 160A pulse BMS. XT90 discharge connector, XT60 charge connector.

Your controller specs a continuous ~105A

And pay attention to DanGT86 here (good advice):

I don't know exactly what your riding style/environment is like but I can tell you its hard to find a situation where you need 100amps continuous on a 72v bike. It takes a very steep hill climb or a really soft terrain to need 7000watts continuous. Your motor will likely not be able to do that for long.

My prediction is you'll be fine with genuine XT90 for the battery/controller connector. Make sure to use a good crimper with appropriate die on the ring terminals.

 

[99t4]

https://www.lowes.com/pd/Southwire-100-ft-8-awg-4-Black-Soow-Power-Cord-By-the-foot/5004687115 It's for the phases, not whatever you're talking about, but it probably could work for that, too.
It says only 30 Amps, but 600 volts. This is what they hook to industrial machines. It'll take more e-bike-type amps..
to an extent. That's 18 thousand watts the wire can take. Aren't watts a measure of heat?
Okay, so you say you want 100A and let's just say 84v. That's 8400w, less than 1/2 of 18,000.

Hold on, you're confusing me. But: : : : maybe you know something I don't? I have been taught to size wire based on amps, not watts. Please explain and enlighten us!

 

[Papa]

I have been taught to size wire based on amps

Basically correct. Also, bundled (grouped) 'power' cables can get hotter, so careful gauge sizing is prudent.

Voltage limitations are primarily determined by the cable's insulation, not the conductor.
Somebody's been smokin' too much wackyweed.

 

[GoFastGus]

You'll fry that motor. That would be my guess. Something will melt.

Satorade and Hubsinks will help with that.

Be sure and have good torque arms.

The plan is mild steel clamping arms w/ high grade fasteners on both sides.

Here's the wire:

https://www.lowes.com/pd/Southwire-10-AWG-3-Black-Power-Cord-By-the-Foot/50148254

It comes in 8, too.

https://www.lowes.com/pd/Southwire-100-ft-8-awg-4-Black-Soow-Power-Cord-By-the-foot/5004687115

I'm looking for each power wire to be 8AWG and each phase wire to be 10 or 12AWG, not to have 4 wires wrapped in an 8AWG package or 3 wires wrapped in a 10AWG package. Thanks though!

That's 18 thousand watts the wire can take. Aren't watts a measure of heat?

My understanding was more amps produced more heat.

Would definitely make for a fast ebike, but is it feasible? Seems like a ton of unnecessary heat dumping to me.
You probably won't go any faster, would be my guess. 41 mph, I'd say. If you can stay on it and don't strip your dropouts.

Some sims from Ebikes.ca, first one is more conservative.

Quick Drumlin tires are good. With heavy tubes.

Any recommendations for a heavy duty tube for a 26x3 bike tire?

 

[E-HP]

Satorade and Hubsinks will help with that.

The plan is mild steel clamping arms w/ high grade fasteners on both sides.

I'm looking for each power wire to be 8AWG and each phase wire to be 10 or 12AWG, not to have 4 wires wrapped in an 8AWG package or 3 wires wrapped in a 10AWG package. Thanks though!

My understanding was more amps produced more heat.

Some sims from Ebikes.ca, first one is more conservative.
View attachment 385879
View attachment 385880

Any recommendations for a heavy duty tube for a 26x3 bike tire?

If you have the 4T leaf, you should open the advanced setting and change the motor kv to about 12.5

 

[GoFastGus]

If you have the 4T leaf, you should open the advanced setting and change the motor kv to about 12.5

I ordered a 10.2rpm/V winding. It was my understanding that this was Leaf Bike’s 4T winding. Am I misinformed?

 

[E-HP]

I ordered a 10.2rpm/V winding. It was my understanding that this was Leaf Bike’s 4T winding. Am I misinformed?

Did Leaf tell you that? Sounds more like 5T, but you should ask them since the Kv has changed over time.

Leaf / leafmotor / leafbike high efficiency 1500w motor

Hi All, So I want to start by thanking everyone for responding to my earlier questions... THANK YOU!! Now for a little background, and my expectations for my upcoming build so that those with more experience might help with a couple of final decisions, and/or point out any glaring faults with...

endless-sphere.com

Leaf / leafmotor / leafbike high efficiency 1500w motor

Charge to a lower percentage than 100%. Problem solved. Actually I think he was concerned that the battery would gain too much charge on the long descent. So even if charged sub maximum (at beginning of the descent) the fear is at some point the battery will reach fully charged before getting...

endless-sphere.com

 

[GoFastGus]

Did Leaf tell you that?

Yeah, they said:
45mph -- 13.1 rpm per volt
35mph -- 10.2 rpm per volt
I presumed the highest winding was 3T, and the 2nd highest would be 4T. Sounds like it’s 4T and 5T.

 

[n00b]

Satorade and Hubsinks will help with that.

The plan is mild steel clamping arms w/ high grade fasteners on both sides.

I'm looking for each power wire to be 8AWG and each phase wire to be 10 or 12AWG, not to have 4 wires wrapped in an 8AWG package or 3 wires wrapped in a 10AWG package. Thanks though!

My understanding was more amps produced more heat.

Some sims from Ebikes.ca, first one is more conservative.
View attachment 385879
View attachment 385880

Any recommendations for a heavy duty tube for a 26x3 bike tire?

Nah, never dealt with such things.
I got the Baboompa Boompa Diamond tread tires, though. That's not bad rubber at all.
2.125 they say. Oh! I'm not doing 26" anymore. Nah, too small diameter.
The Baboompa Boompas take the the place of what used to be some Cheng Shin tires with gumwalls back in the day.
I used to ride city streets for most of the time, but for the trails it was Cheng Shin 40-lb tires.
I had a separate wheelset, and it was all quick-release. Have a tire with the same tread on a back wheel right now.
The other one was messed up and wouldn't catch the bead of the rim.

This is the diamond tread:

Cheng Shin C241 Street Bicycle Tire (Wire Bead, 26 x 2.125, White Wall) | eBay

Cheng Shin C241 Street Tire .20” x 2.125" .Wire Bead . Classic white skin wall street tread for juvenile bikes. Also popular for low riders. Cheng shin C241 street tire Wire bead, 26 x 2.125-Inch Classic white skin wall

www.ebay.com

VINTAGE ANTIQUE BIKE BICYCLE 26 INCH TIRES CHENG SHIN 26 x 2.125 TAIWAN DRY | eBay

A PAIR OF CHENG SHIN TIRES. BUT ARE OLD AND DRY. 26 X 2.125. THESE ARE NEW NEVER USED.

www.ebay.com

^Things used to be $40 back in the day.
I can't find the ones online, but I have 1 that works. It's the "Arrow" tread.
Pretty sure it was like this with gumwalls.


Ya know, I think it was a little different than that.
Gah! This is aggravating. I cannot find the same tread, and I had it on my mountain bike and 2 motorcycles.
Good for road and the dirt. Those tires never did pop. The sidewalls rotted out from the sun.

 

[n00b]

Hold on, you're confusing me. But: : : : maybe you know something I don't? I have been taught to size wire based on amps, not watts. Please explain and enlighten us!

How many amps does it take to propel a human being?

 

[n00b]

Yeah, they said:
45mph -- 13.1 rpm per volt
35mph -- 10.2 rpm per volt
I presumed the highest winding was 3T, and the 2nd highest would be 4T. Sounds like it’s 4T and 5T.

Then you don't need that many amps, and what you need is volts.
Amps provide torque, volts provide speed.

Observe hellbike. That's not comfortable. Gotta gimp that. Too fast.
You gotta wind it out just to get going to insane.
I'm not liking it. Legs are still sore.

 

[Apartunis]

How many amps does it take to propel a human being?

Amps are only half the equation. They dictate minimum wire size and they provide torque. Volts provide rpms and the "push" to move enough amps. Motors confuse the issue because they can trade torque against speed, amps against volts depending on how they are wound. One thing is certain. No matter how the motor is wound, its max torque is the same. The amount of heat it makes to produce a given torque is the same. So if you want mega power, you use a fast winding and feed it mega amps. If you want a slower but efficient motor that can use unremarkable batteries and cheap controllers, you use a slow winding and feed it underwhelming amps .

 

[GoFastGus]

Then you don't need that many amps, and what you need is volts.
Amps provide torque, volts provide speed.

My last bike was 52V ~35A on a 3T winding. It topped out at 45 but it was a slog from a dig. At 72V 100A with a 5T winding, this should have good top speed and acceleration.

 

[n00b]

My last bike was 52V ~35A on a 3T winding. It topped out at 45 but it was a slog from a dig. At 72V 100A with a 5T winding, this should have good top speed and acceleration.

I usually run 72v (62-84) and 26-32A controllers. It might would be a good idea to switch out the controller on a 200W 9C-type hubmotor for something with more amps, aye? For whatever reason, that bike doesn't develop full power until the vdroop hits 79.1v.

 

[GoFastGus]

Update:
Finally pressed in the headset, it took a few tries since it was my first time pressing bearings. I couldn't get the bearing to go in straight by pressing it in using a threaded rod, nuts, and wrenches, so I got it started that way and the local makerspace expert pressed it in the rest of the way with a hammer and two blocks of wood. The steerer tube is just barely long enough for the external cup headset and the handlebar stem.


The hub motor came, single speed freewheel and extra wide rim as requested. It even came with a 16T freewheel, so that can get me started when I eventually get a TSBB. I ordered satorade from Grin, so I'll have to install that in the hub motor. I tried to uninstall it like these instructions show, but even after a couple vigorous shakes it wasn't separating. I didn't want to go absolutely crazy shaking it without being absolutely certain that that's the way to do it, so I'll double check and try again later.


Preview of what the rear end will look like. The torque arm model fits the disc brake and the axle, I'll probably want to lower the bottom fastener hole by 5-10mm so that way the axle easily clears.


My idea for the next version before I laser cut or mill anything. Red would be added onto the torque arm, with 3 holes to fasten it to a bar of steel (blue). The steel bar would then be attached to the frame with U bolts. Hopefully this would be more than enough for my use case.


Small issue with the wheel, it's closer to the passenger side than the driver side. Is this something that a local bike shop could re-true, or would I need to re-lace the whole wheel?

Silver lining: the axle is easily long enough for 10mm torque arms on both sides and axle nuts. Between axle nuts, clamping torque arms, and u bolts attaching torque arm extensions to the frame, I really hope this axle has absolutely 0 play.

In the mail: 52-90V to 48V 2A stepdown converter (for CA3 and headlights), Fox RP23 rebuild kit, Satiator kit, left ebrake lever, battery bag, XT90S connectors, bike seat.
Still need to order: Kenda Kraze 26x3" rear tire, 26x3" tube, red and black 8AWG wire (if not at makerspace), light kit.
Still need to make: final torque arm designs, torque arms, battery bag bracket, controller mounting brackets.

 

[scianiac]

I would just see if I could shim the motor over slightly before trying to move the rim via the spokes, don't know if you'll get far enough to be perfectly centered with adjusting spokes alone without replacing them of course.

 

[GoFastGus]

I would just see if I could shim the motor over slightly before trying to move the rim via the spokes, don't know if you'll get far enough to be perfectly centered with adjusting spokes alone without replacing them of course.

That's gonna be my first solution. This was a problem on my last build, and centering the wheel cost me the ability to freely rotate my cassette. This time, I'm using a single speed freewheel and I'm a ways away from setting up a torque sensing bottom bracket, so that's a faraway concern. If I can't shim it into place, I'll take it into the local bike shop and ask what they can do by adjusting the spokes. I need to learn how to build wheels eventually, so my next wheel I might just build in order to finally start the learning curve.

 

[scianiac]

Wheelbuilding is a worthwhile skill and honestly pretty easy to learn, it takes time to build a wheel but is one of those enjoyable almost meditative tasks.

 

[DanGT86]

My experience has been that spokes on powerful hubs loosen after the first few rides as they settle. Almost like a break in period. Once stressed and retightened they stay.

If you are open to taking it to a shop you might as well try to re-dish it yourself. They can be your backup plan.

Think of the spokes in 4 groups. Left-push, Left-pull, Right-push, Right pull.

To center the rim (re-dish) the wheel just go around the whole wheel one group at a time. So to move it left loosen every right pull spoke by 1/8 or 1/4 turn and tighten every left pull spoke by the same. Then move to the push spokes.

I like to think of it as balancing everything I just did to one side and direction before moving on.

People mess it up by messing with adjacent spokes a and as they get around the wheel the error is compounded.

Its like trying to push a rope or scoot a big rug. Do the same small change at multiple points rather than bunching it all up larger as you go.

Also, make sure you pay attention to if the nipple is turning or the spoke is just twisting. So keep one hand on the spoke while you turn the nipple. It will likely be like 1/4 turn of nipple creates an 1/8 turn of spoke and 1/8 turn of actual nipple tightening. So you can twist back to de-stress the spoke.

With a new wheel that is already true the forces are very consistent. It can be as easy as just counting turns and it will stay true. Same with re-tensioning after the first break in rides. Go all the way around one group at a time rather than chasing trueness.

 

[GoFastGus]

My experience has been that spokes on powerful hubs loosen after the first few rides as they settle. Almost like a break in period. Once stressed and retightened they stay.

Sounds like I should get the bike fully assembled before I start worrying about these smaller details.

Think of the spokes in 4 groups. Left-push, Left-pull, Right-push, Right pull.
To center the rim (re-dish) the wheel just go around the whole wheel one group at a time. So to move it left loosen every right pull spoke by 1/8 or 1/4 turn and tighten every left pull spoke by the same. Then move to the push spokes.
I like to think of it as balancing everything I just did to one side and direction before moving on.
People mess it up by messing with adjacent spokes a and as they get around the wheel the error is compounded.
Its like trying to push a rope or scoot a big rug. Do the same small change at multiple points rather than bunching it all up larger as you go.
Also, make sure you pay attention to if the nipple is turning or the spoke is just twisting. So keep one hand on the spoke while you turn the nipple. It will likely be like 1/4 turn of nipple creates an 1/8 turn of spoke and 1/8 turn of actual nipple tightening. So you can twist back to de-stress the spoke.

I'll give that a shot after my first few rides. How do you tell the difference between push and pull spokes?

With a new wheel that is already true the forces are very consistent. It can be as easy as just counting turns and it will stay true. Same with re-tensioning after the first break in rides. Go all the way around one group at a time rather than chasing trueness.

Sounds good, I'll keep that in mind!

 

[n00b]

Satorade and Hubsinks will help with that.

The plan is mild steel clamping arms w/ high grade fasteners on both sides.

I'm looking for each power wire to be 8AWG and each phase wire to be 10 or 12AWG, not to have 4 wires wrapped in an 8AWG package or 3 wires wrapped in a 10AWG package. Thanks though!

My understanding was more amps produced more heat.

Some sims from Ebikes.ca, first one is more conservative.
View attachment 385879
View attachment 385880

Any recommendations for a heavy duty tube for a 26x3 bike tire?

I just linked you to heavy duty wire that works. What you do with that is up to you.
You split the case open and use the wire, dude.
Wire like that is used in 440v machinery, pretty sure it'll take e-bike telephone voltage.
Tires seem kinda wide. I've been using those Walmart ones.
They're like..red and tan. "Blackburn" Heavy Duty tubes.
3" is kinda wide, you might need something else. Possibly underinflated 4" tubes if you can stuff them in there.

 

[GoFastGus]

Side note:

I'm thinking about the wiring for my electronics, and I think I'm gonna have to change the connectors on the throttle, brake, and ignition wires.

Reminder what my controller connectors look like, I think they're called 2.8B connectors. They don't match the JST SM style that the CA, the brakes, and the throttle use. I think I'm gonna swap the necessary controller connectors to JST style so i can hook the CA, brakes, and throttle right in. Any thoughts or advice?