Put riding a 23kw ebike on your Bucket List

[John in CR]

Before they die everyone who's wouldn't kill themselves in the process should get the opportunity to ride a 20kw+ ebike. I'm not talking about one with phase current set too high resulting in 20kw at very low efficiency. I'm talking about one tuned to hit peak current during acceleration between 35 and 40mph, so as the motor crosses it's peak power point you get an extra boost in thrust on top of already eye popping performance. I can only imagine what it would feel like for someone who weighs a lot less than my 250lbs.

I thought 16kw was a lot of fun, but 280A at voltage sagging to 73V is even better. I thought LFP was crazy, but now I understand because I want even more. Nano Techs and another blower here I come, because Hubmonster still isn't getting hot.

John

[liveforphysics]

I know the feeling you're describing, and I'm really glad to see you experiencing it and loving it. It's something a very low number of folks have experienced, it's a thrill a motorcycle superbike can't provide, something about being a bicycle just increases the excitement and intensity factor through the roof.

You gotta try 680amps at 116v sometime. It's enough to requiring a change of religion and shorts.

I can't wait until my second controller arrives and I'm pushing >1300amps at >110v.

[John in CR]

I take it back you are crazy. LOL. You're right ebikes are truly unique and it doesn't have to be at monster power. I figure it's gotta be due to the relative silence combined with our bodies being the primary component of total vehicle mass....Just like I'm sure jets are fun, but the guy strapping on wings and a couple of jet engines has a very different experience.

Now I also understand why you guys had to head out of town for your street racing. It's gotten to where I have to go to another town to hunt down motos. The local ones have seen or heard about my bike, and they hide instead of pulling up to the front at the red lights to avoid getting embarrassed by a fat guy on a bici. If I sneak up from behind they suddenly decide to turn or simply concede.

Now that I have an hubmotored ebike worthy some fun for you, you've gotta get back down for a visit. It won't leave you trembling, but it still beats any amusement park ride.

John

[ElectroSurf3r]

Should have turned it up sooner!!! I'm so jealous right now.
You have to get video cameras forward/rear, and work on that power-to-weight ratio since I now have to live with video porn like the rest of 'em.
Makes me wonder what the other controller will be able to feed Hubmonster...

[John in CR]

Should have turned it up sooner!!! I'm so jealous right now.
You have to get video cameras forward/rear, and work on that power-to-weight ratio since I now have to live with video porn like the rest of 'em.
Makes me wonder what the other controller will be able to feed Hubmonster...

Sorry, no video. They don't do performance any justice anyway. You'll have to hurry up and get back to experience it first hand. Don't worry I'm working on the power to weight ratio from both directions. BTW, I weighed her this morning and SuperV is a hefty 117lbs with 20s20ah aboard, so I have little doubt I can knock 20lbs off of the bike with at least 10lbs just off the motor. 30 off me should be simple too. That's a 13% increase right off the top. I was having so much fun today that I ended up doing a lot more hard launches than I intended for a first outing at higher settings, but since the controller survived I'm sure that another blower and moving it to in front of the down tube will safely allow another 70A or 350A battery side. Add in some nanotechs to stiffen up the voltage and that's over a 50% increase in the power to weight ratio with very achievable changes nibbling from every direction. A 50% increase when I'm already starting to do power wheelies as I'm finishing a curve is going to be sphincter puckering to say the least.

Of course my plans pale compared to Luke jumping straight to 1300A at 110V, which will be sick if he can keep the front wheel down. Unless some huge weight gain comes with it, he'll be able to slaughter just about any wheeled vehicle on the planet not specifically designed for the 1/4 mile, and probably make a respectable showing against them.

John

[lazarus2405]

I have to wonder, what on earth sort of controllers are you folks using to push >100a at >100v?

I'm at the limit of what my Kelly can provide at 90v absolute maximum, and I'd like to get educated on the next steps. 20kw... *whistles*

[nechaus]

im slowly getting there..

i should soon feel max 20 kw with the hpm 5000b...
but i have a feeling im going to get an agni bicycle

[Farfle]

Its Fcking awesome

[neptronix]

I have to wonder, what on earth sort of controllers are you folks using to push >100a at >100v?

I'm at the limit of what my Kelly can provide at 90v absolute maximum, and I'd like to get educated on the next steps. 20kw... *whistles*

You need 4115 FETs and lots of them .. 36 might do!

[deVries]

Of course my plans pale compared to Luke jumping straight to 1300A at 110V, which will be sick if he can keep the front wheel down. Unless some huge weight gain comes with it, he'll be able to slaughter just about any wheeled vehicle on the planet not specifically designed for the 1/4 mile, and probably make a respectable showing against them.

John

Question IS: Will Luke finally do the 1/4 mile run we've all been begging for since the beginning of 2012>>>

[John in CR]

I have to wonder, what on earth sort of controllers are you folks using to push >100a at >100v?

I'm at the limit of what my Kelly can provide at 90v absolute maximum, and I'd like to get educated on the next steps. 20kw... *whistles*

You need 4115 FETs and lots of them .. 36 might do!

This motor would eat 4115's by the shovel full. It's heating up 36 irfb4110's so much that I had to install a blower to push fresh air through the controller, and it looks like I really need to add a 2nd blower as well as move the controller to the downtube so it gets full force air flow to the case. I'm seriously considering going to oil cooled. My controller needs it, not my motor.

I'm not interested in high voltage anyway. The bike does almost 60mph with 20s of sagging 20c lipos, so going just to 24s of less saggy nanotechs would put it past 70mph. That's too fast for me for 2 reasons:
1. I use WOT pretty much only during acceleration. Continuous would only be useful to me on the highway, and even then anything much above 50mph isn't pleasant due to the wind. Give me hard launches and relaxed cruising. I'll leave the high speed to you guys, but if you can't pass the 82mph pedal bike record, then you should be embarrassed to talk about being fast with a motor on your bike.
2. I tackle hills and mountains on most rides, and increasing top speed by adding voltage means the minimum speeds required to keep you motor and controller safe go up too. I have to slow down for curves going up steep hills already, so going up in voltage would put a lot more stress my system in the form of more heat, lower efficiency, and higher phase currents with very little gain in useful performance.

FWIW, I've settled on a phase/battery current relationship of 13:10 . Lower than that suppresses launch acceleration and top speed, though I don't understand why it affects top speed. Higher than that makes the bike unmanageable, and with my big load with much lower and more forward CG than typical along with a longer wheelbase I still have to work to keep the front wheel down. Sure I give up some thrust from a dead stop, but I don't care about the first 2 or 3 tire revolutions. The last thing I want to do is pull up to the front of traffic at a red light only to get flipped on my back when the light turns green.

John

[ZOMGVTEK]

My bicycle, with me on it, is 15.6lb/kW. 15.6lb/hp assuming 75% efficiency. It feels fairly quick for a bicycle, but its somewhat hilarious how quickly it reaches its super low top speed.

It probably helps that my total vehicle weight is 'only' 250lbs. It sure is a bit odd when your body weight is more than the weight of the vehicle propelling you.

[John in CR]

My bicycle, with me on it, is 15.6lb/kW. 15.6lb/hp assuming 75% efficiency. It feels fairly quick for a bicycle, but its somewhat hilarious how quickly it reaches its super low top speed.

It probably helps that my total vehicle weight is 'only' 250lbs. It sure is a bit odd when your body weight is more than the weight of the vehicle propelling you.

Have you ever seen the 16kw displayed while in motion? I don't doubt that your bike jumps up to speed super quick, but with such low gearing and very light load it's likely that current is spiking at launch and you simply aren't putting enough load on the motor to see max power at the wheel. To get a good estimate of your useful power at the wheel, reset your CA and set it to the screen with peak current. Then use your pedals to get going and slowly accelerate to about half speed, and verify that current hasn't spiked in the process. Now crank on the throttle and take it up to full speed. As long as your CA is well calibrated the peak current displayed should be a pretty good number to apply your 75% efficiency number to determine power at the wheel. That's making the pretty big assumption that the stator isn't into saturation at that kind of phase current level. Please share the results of those runs, because my understanding of hubmotor operation is continuously evolving, and if that motor is capable of 10kw+ output at without pushing it way into saturation, then I need to tweak some of my views.

Hubmonster is in a different league with a 25% wider stator and magnets plus a 32% greater stator diameter. Plus the 19" wheel allows it to make use of the more than double Kv resulting from 1.5 turns of copper on each tooth using a bundle of magnet wire roughly equal to 8AWG, so it's not a fair comparison at all. Of course, a fat guy like me needs a motor like mine.

Your ebike is definitely no slouch. I'm not knocking it at all, just trying to add a bit of perspective. My bike's 20kw+ input is putting 15-16kw out at the wheel somewhere in the 35-45mph range. It's a unique experience that everyone deserves. Be warned though, it's addictive.

John

[ZOMGVTEK]

The power is coming out of the battery. How much is making it out of the motor, I have no clue.

The controller is flashed to 160/300, it tends to run 16.x kW on a hot pack, which dips near 14-15 at a lower SOC. I didn't calibrate the shunt at those currents, so its definitely likely a bit off as the shunt heats. Unfortunately I have no good way to measure average power with high accuracy at those currents. At the end of the day, the number is not that important.

The bike only goes 42, so it can be a bit hard to measure power accurately with a few seconds to sample.

[dogman]

Definitely on my bucket list too, but with a crotch rocket 250 motorcycle frame, and body armor. We have a high speed sports car and motorcycle track nearby for that.

Now where the money for it comes from, that's the problem. Set of tires per day, that sort of thing gets pricey.

[ElectroSurf3r]

A 50% power-to-weight increase (from a faster setting than I experienced) will feel AMAZING. I have to get back down there asap.
Of course, I can't even begin to comprehend Luke's >143kW, that's just nasty. Pretty much a DIY Killacycle

[John in CR]

A 50% power-to-weight increase (from a faster setting than I experienced) will feel AMAZING. I have to get back down there asap....

Last time I checked there were plane flights daily.

I'm just going to make it harder and harder to stay away. I really want to move hubmonster over to one of the recumbent frames. A back rest and being lower makes acceleration more visceral. I liked how that chopper bike felt on takeoff at just 6kw input, so more than triple that should be a blast.

John

[liveforphysics]

A 50% power-to-weight increase (from a faster setting than I experienced) will feel AMAZING. I have to get back down there asap....

Last time I checked there were plane flights daily.

I'm just going to make it harder and harder to stay away. I really want to move hubmonster over to one of the recumbent frames. A back rest and being lower makes acceleration more visceral. I liked how that chopper bike felt on takeoff at just 6kw input, so more than triple that should be a blast.

John

You're tempting me too John. I miss that area, it's beautiful.

[MadRhino]

CR sure is a beautiful destination. A friend just came back and make me feel I should go there some time during the winter.

I consider my weight- bike -power ratio is good

My weight 176 Lbs
Heckler road racer 57 lbs
Demo 8 68 Lbs
V 10 74 Lbs

all of them are fed 24s 150a batt current

[John in CR]

You're tempting me too John. I miss that area, it's beautiful.

You're welcome any time of course. Everything was still brown last time you were down, so it's much more beautiful now with everything different shades of green. I comes with a price though, at least some rain most days. The new house is great, no separate guest house, but far better roads and bikes certainly makes up for that.

PS- We took SuperV down to the beach with us, and the guy at the 4-wheeler rental place who took red for a test ride when you and I were in Jaco was a total puss and was scared to give SuperV a go, even with the reduced speed switch. On top of that it stormed all night, so we didn't get to do any of the night time ebike fun you and I had.

Once I get some electric watercraft going, then you absolutely have to come down. Maybe in the meantime we can get you to try a manly hubmotor.

John

[John in CR]

CR sure is a beautiful destination. A friend just came back and make me feel I should go there some time during the winter.

I consider my weight- bike -power ratio is good

My weight 176 Lbs
Heckler road racer 57 lbs
Demo 8 68 Lbs
V 10 74 Lbs

all of them are fed 24s 150a batt current

MadRhino,
You're a DHer, so your bucket list needs to be on a totally different level from the rest of us. An ebike thing it would have to be nothing less than whatever is Luke's latest and greatest. I do need to come up with a screaming mid-drive offroad ebike for you to test though.

John

[John in CR]

June 5 Update:
It turned it up even more today. The turbo thrust went away, so I think I need to turn the battery current up even more while keeping the phase current limit at 405A. I like the afterburner effect and want that back. It hit peak current at about 30mph, so I can confirm that 30hp input at 30mph makes for a FUN ebike.

CA at 320A 405A.JPG (45.08 KiB) Viewed 73 times