Holy CRAP! 125V@102A into a cromotor, Video

[Microbatman]

Zombiess.
For you to be impressed that says alot!!!!
I mean I was impressed with you riding the 9c at 50++ mph. Now that you are saying this baby has scary torque.
Can't wait to see some wheel spinning roster tail dirt kicking vids.

[zombiess]

I do have a long 10 mile hill close to me... should be close to 8-10% and I ll climb it when I get a new swing arm (i was stupid and broken mine).

Voltage ll be close to 90v (24s zippy 8ah 2p) outerdiameter is pretty close to 24" maybe 23.5"
Im really not that worried about top speed I just want to go from 0 to 35mph in under 3 seconds.

0-35 in under 3 seconds no problem... if you have good geometry/suspension setup/skills/can ride a unicycle hehe. 45mph will be no problem but you'll probably find yourself going to 24S3P like me because the amps are so addictive.

Since you will be running that controller near it's max voltage keep your battery wires as short as possible to the controller, use 8 gauge and possibly twist them to help minimize the inductance. Oh yeah, hold on tight and be ready to back off the throttle if you see sky. My suggestion is to start off at lower amps and work your way up unless you are already there now like the rest of us nuts

I'm turning mine down for commuting because it's too much to ride without accidentally looping right now + I want my controller to stay alive.

[chroot]

Video in action please

[fractal]

Same for me, I like torque and accelaration from 0 to 40mph. I will also run mine at 24s. My setup will be 12 bricks of 6s 5ah Turnigy lipos Wired in a 24s 3p config. I have the Lyen 24 fet «freeway controller» that is rated at almost 8kw. My wheels are being built as we speak by JRH = 17 inch moped rims, 12g spokes with 2.5 gazelle tires. Outer diameter is about 22.5 inches. I bought some harnesses from Icecube = mix of 8awg and 10awg with 4mm bullets, precharge resistor, fuse, ...etc. I also got some of Method's LVC/HVC boards to dumb proof the whole thing. Man, I look at the bike and the parts sitting in my basement everyday and I dream about riding it when the snow is gone!!!!
*** What kind of performance will I get with 22.5 inch OD wheels?

[MadRhino]

He, we are still waiting for a vid of this motor powered with big amps.

I just received the spokes for mine, to lace in a 24 in bicycle wheel. Not ready yet to ride it, for we are n the snow here. The build is for the spring, so I rely on you guys who have nice weather, to inspire me.

[hillzofvalp]

Id like to try this motorin my 29er.. (700c). Wht phase amps/battery amps u running?

[oatnet]

Congrats zombie!

Glad to see it up and running.

-JD

[liveforphysics]

Id like to try this motorin my 29er.. (700c). Wht phase amps/battery amps u running?

A large part of why this bike rips is because of the small wheel.

You would have roughly 45% less torque and 45% less power for any given speed in a 29" wheel vs the 21" wheel.

That would likely still be great for most applications, but do keep in mind that using a 29" wheel with this motor would perform about like putting a 300lbs rider on the bike rather than a ~180lbs rider.

[hillzofvalp]

But compared to my 2807?

[Samd]

+1 subscribed. Video would be fapworthy.

[Alan B]

Cromotor Speed Estimation

The Cromotor motor is about double the power of a 9C.

You can do a quick calculation and based on 55 mph from 125V in 21.5" wheel like this:

your speed approximately = your voltage / 125 * your tire diameter / 21.5 * 55 mph

So an 18S Lipo and 17" moped rim comes out about 35 mph. Hills will be ignored.

[John in CR]

A 17" moped rim has a 17" rim, and the OD of the wheel will depend on the tire, but in all likelihood it will be greater than Zombies's. It's not like the retarded bike convention for tires.

[John in CR]

Zombiess, great reporting, but we need to know your weight for any kind of informed comparison.

[Alan B]

A 17" moped rim has a 17" rim, and the OD of the wheel will depend on the tire, but in all likelihood it will be greater than Zombies's. It's not like the retarded bike convention for tires.

Yes, of course you are correct. I used 23.5" for the tire diameter in my calculation above.

[Alan B]

Zombiess, great reporting, but we need to know your weight for any kind of informed comparison.

John what is magnet width and diameter of your dualspeed hub? How does that compare with Cromotor? (There is more to compare, but these are easy, the other items are not so easy).

[John in CR]

A 17" moped rim has a 17" rim, and the OD of the wheel will depend on the tire, but in all likelihood it will be greater than Zombies's. It's not like the retarded bike convention for tires.

Yes, of course you are correct. I used 23.5" for the tire diameter in my calculation above.

You caught me not paying attention to the voltage difference, though that's probably a bit big for a moped tire. My moto tires on a 17" are right at 23.5" and they're a lot higher profile than the moped tires I've seen. The huge difference in wind resistance will offset that in the other direction.

Also, once you get into those speeds tire size becomes pretty unreliable. eg My bike that Luke had up to 61mph when he was down pushing 120A battery side through the controller at 74V nominal (20s) had that 23.5" diameter wheel I mentioned above. My daily rider with the same motor is much lower and runs a 20" OD wheel, a moto 14" rim and tire, and it comes very close to the same top speed with the same voltage but at only 75-80A battery side. The moral of the story is that overcoming the wind is everything. If I tried that hubbie Luke used with the 17" rim on the bike I'm currently building, I have no doubt it would push through 70mph. Don't forget, I weigh 250lbs too, so weight has little to do with speed, except on hills, but it matters for acceleration.

[johnrobholmes]

... My wheels are being built as we speak by JRH = 17 inch moped rims, 12g spokes with 2.5 gazelle tires. ....

Ahh, so this is your wheelset I have been working on They are both loose laced and will be trued tomorrow.

[John in CR]

Zombiess, great reporting, but we need to know your weight for any kind of informed comparison.

John what is magnet width and diameter of your dualspeed hub? How does that compare with Cromotor? (There is more to compare, but these are easy, the other items are not so easy).

My high efficiency motor is a completely different animal, so I'll resist comparisons. The Cromotor is more like the motors I've used for 3 years, but with a 50mm stator instead of 40mm. Call the Cromotor a brute force beast that kicks the crap out of the old X5 (as long as you don't need to do pedal only) and be done with it. We should have had motors like this almost 3 years ago, but the factory I dealt with refused to believe that anyone would want this kind of power on a bicycle, so they didn't want to do a bike friendly axle and right side cover for me. Rephrase that, they refused to do it without a 1000 motor order. Of course I didn't know then how easily I could have ordered axle's and side covers only on the side, since this diameter motor has become a mainstay in China. Now ordering parts and pieces has become quite easy, and thankfully some Chinese guys are racing their stuff, so the guys with the parts available to them dirt cheap are figuring out how to stuff as much motor as will fit in 135mm width.

[zombiess]

I weigh 170lbs again I was up to 177lbs after vacation because I was eating good but now I'm suffering killer jet lag/sickness and am back down to 170lbs... grrr I'm 6'1. Call me 175lbs geared up to ride. I'm living on anti nausea medication right now, might have the flu or just really bad case of jet lag, I hate going West to East and I'm doing it again next week going to Europe for a week.

Found out something really interesting about the controllers I'm using and a problem I was having at low speed after doing the shunt mod. Turns out I was running 102A battery 80A phase. The EB3XX controllers are different. Prior to my shunt mod I was pulling -15ish amps on regen using setting 2, after the shunt mod dropped my shunt to 0.52x mOhm I'm still pulling -15ish amps on regen setting 2 instead of getting stronger as in previous models. Controller expects a 1.5mOhm shunt for software to be accurate so now I triple the battery current setting to figure out what I'm really pulling. Tested this tonight. 20A battery current = just over 60 amps.

Starting a new thread in the tech section about this http://endless-sphere.com/forums/viewtopic.php?f=2&t=35890, maybe others know this info but I didn't. Set phase battery amps to 60 (programmed it for 20A) and phase amps programmed to 100A and my low speed take off problem was gone and wheelie city was back. 1:5 ratio battery to phase current and this thing is an animal on just 60A battery 100A phase, a lot smoother too. I'll have to try upping the battery current to see how it effects things.

I was so busy testing setting troubleshooting this problem that I forgot my temp probe until I was done, but ran an grabbed it as soon as I realized the controller was warm so about 1 min between power off and temp readings.

FET Temp 48C
Ambient Internal temp 55C

FET temps were dropping faster than the ambient internal temp which was dropping much slower.
Hand on the cover motor temp check, slightly warm, even 10 mins after shutting it off

I tried different settings and was up to 102A battery current at one point again. Went back and edited my posts on phase amps.

Videos will be tomorrow or Saturday now that I figured out this last issue. Gotta get my rear brake installed tonight, I need it desperately.

[gensem]

LoL... that means your take off would be much faster and that also means your controller would probably smell bad with 100/240

[zombiess]

LoL... that means your take off would be much faster and that also means your controller would probably smell bad with 100/240

Take off... more like reverse catapult. At 100A phase and switch on the high setting I must be careful with the throttle from a stop.

Forgot to mention, top speed today was 56mph in the neighborhood. I wonder if this has the ability to put me in the 60mph club

[John in CR]

I weigh 170lbs again I was up to 177lbs after vacation because I was eating good but now I'm suffering killer jet lag/sickness and am back down to 170lbs... grrr I'm 6'1. Call me 175lbs geared up to ride. I'm living on anti nausea medication right now, might have the flu or just really bad case of jet lag, I hate going West to East and I'm doing it again next week going to Europe for a week.

Not jet lag, just a lack of good food. If you stayed with us for a few months, I'd put some meat on your bones with some good ole cajun cooking.

Load your bike down till it weighs 125lbs. Then put 90lbs in your backpack, since I ride around with at least an extra 10 on my back, and then we can compare performance for Alan B. Of course I'll just pull out my trump card with Hubmonster on my modded SuperV, which bows down to give hommage only to LFP's monster bike. That wouldn't be fair though since it's a bigger heavier motor that could never fit on a regular bicycle, which I'd consider insane anyway. You modded yours nicely, but with your light weight and high CG, you'll never be able to fully utilize the Cromotor. You might as well send it to someone who can give it a good workout, such as me.

If someone wants the most powerful hubmotor designed to fit regular bike dropouts, then I believe the Cromotor is it. Of course that's only until someone comes out with one made using a 40-50mm long stator with one of the larger diameter stators and rotors currently available.

[John in CR]

Zombiess,

WRT your current limit issues, doesn't your motor sound odd? Mine sound current starved below a 2.5:1 (phase/battery) current ratio. It's gotta be that your low weight isn't presenting much load for that big motor.

[zombiess]

Zombiess,

WRT your current limit issues, doesn't your motor sound odd? Mine sound current starved below a 2.5:1 (phase/battery) current ratio. It's gotta be that your low weight isn't presenting much load for that big motor.

Motor sounds good now at low rpm that phase amps are set at 100 and battery at 60A. Load caused an issue before I upped the phase amps and it would kinda cut out if I wasn't gentle at low RPM on both the 9C 2806 and the Hubzilla which led me to today's testing. I don't think the old battery current multiplied 2.5 times battery current holds true any more on these controllers but lets move this discussion to my new tech thread I created about this. Are you using an EB3xx controller? I suspect these are a slightly different animal than the EB8XX and EB2XX series (I own all 3 but have the most experience with EB3XX).

[hillzofvalp]

I want acceleration times.