is 3kw too less to wheelie in a 20" wheel ???

[izeman]

i'm a bit disappointed. i finished my 20" 3540 crystalyte conversion with a 40a @80v 12fet lyen controller to the point to try it out. not really try it out for high speed. only in the garage as it's too cold outside, just want to see how it behaves.

i thought this bike would be hard to tame during take off. i programmed the controller as eb318 to 40a battery and 90a phase. not the max possible but it should be ok. block time 1s (standard).
i tried with different ca-v3 throttle ramp settings, setting those to 0.2s/v so a quite agressive throttle.

there are no limiting settings set at the ca - i can even remove the ca and plug the throttle into the controller directly.

when trying it out for the first time i was VERY cautious, and prepared to pull the brake, because i thought the front wheel would lift easily. but paaahhhh. nothing. just a soft nice start. even giving 100% from a full stop does nothing to take really care off. i starts to move, but that's it.

what is going wrong? i got my mac 8t with 30a @50v and tipping the thumb throttle make the wheel jump up. doing "gas wheelies" at low speed is easy. and now? with double the power and a high torque motor with a small wheel - nothing?

please help me

 

[captain387]

The 3540 is the high speed wind, but I would have assumed some torque from that setup.
What is the current with the wheel off of the ground? Could it be a Hall / Phase combo issue?

 

[izeman]

Yes high speed wind, but in a small wheel. Compared to my MAC in a 26in still a torque wind. Sensors can't be the problem. Tried with a sensored and sensorless controller. Same result.

 

[electr0n]

I have been able to lift the wheel off the ground with my HS3540 in a 26" wheel and front mounted batteries no less with about 50 to 60 battery amps and 88.8 nominal, can't remember phase amps but around 1.5. I don't get a full wheelie but the wheel lifts a good couple inches off the ground if give it a little too much throttle from a stop. Are you heavy or using a long wheel base or something?

I'm about to move to a 20" wheel for better acceleration and I'm expecting a wheelie prone touchy ride with significantly improved acceleration, then again I'm peaking 6 to 7kw.

 

[izeman]

i maybe will try raising battery and phase amps and see what will happen. using ebikes.ca's simulator is doesn't seem to make any sense going above 40a. maximum motor power seems to stall above 3.5kw. but my 12fet should be good enough for 60a/100a.
today i'll make a test on the street. i expect top speed to be good. what i don't like is acceleration.
btw: i'm not that heavy - 90kg, but i have a 10cm longer wheel base and a have 15kg battery at the handle bars.

 

[dogman dan]

False positive phase order does make sense. Surely the right colors are known for that motor/controller set , so how could it be that?

Could it be the battery isn't up to 3000w?

Look at the plug just for grins, but if it was that, you'd expect some stutter.

 

[izeman]

it's a sensored setup. and it's starting really smooth. no stuttering.
i programmed the controller as eb312 and set battery to 60a and phase to 110a. now, this is fun now it works as was hoping it to behave at 40a. the front wheel is not lifting, but it accellerates quite nicely.
i will measure shunt to see if it's correct.
i now can easily reach 65km/h, and climb a 15 degree street with ease at 55km/h. but my ca shows 4500w (corrected from 6500w). which is too much on the long run for both - the motor AND the controller.
i will investigate further.

edit: i calibrated the ca with my icharger and shunt value was wrong. i have 2 eb312 from lyen. first one was 1.333mohm, second was 1.935mohm. so amps and watts shown were 40% too high. to i corrected those 6500w above to 4500w. this is much better.

still it needs to be found out why the start is so super soft with 40a programmed. this is far from what i expect.
needs lyen's eb312 be programmed as eb312 or eb318? there is still some confusion.

 

[ZOMGVTEK]

Bikes do wheelies at 3kW? My bike takes about 13-14kW before it lifts the front wheel, one with a short frame and terrible seat position required about 5-6kW. Even then, lean forwards a touch and it's stable. My brother is running 7kW into a 26" low speed golden and you can pull back on the bars and it while you snap the throttle, it usually falls back down.

 

[MadRhino]

A bike will lift or drift with various power level according to its frame geometry.
You can build a bike that will lift with very low power, or one that will never lift no matter the power. :wink:

 

[Ypedal]

A bike will lift or drift with various power level according to its frame geometry.
You can build a bike that will lift with very low power, or one that will never lift no matter the power. :wink:

Agreed

 

[Dauntless]

Bikes do wheelies at 3kW? My bike takes about 13-14kW before it lifts the front wheel, one with a short frame and terrible seat position required about 5-6kW. Even then, lean forwards a touch and it's stable. My brother is running 7kW into a 26" low speed golden and you can pull back on the bars and it while you snap the throttle, it usually falls back down.

And here I thought pedal power was just like 200w. I remember the wheelies when I was a kid, high school even. . . .

 

[izeman]

Then it's OK for me. I have a 10cm longer wheelbase to avoid that and the heavy battery at the handlebars. Nevertheless I miss this immediate response to the throttle.
The motor is supposed to do 40km/h @48v in a 26in wheel. I need to limit the bike to 25km/h and 600w for legal street use. If I set these limits in the CA its hard to reach even 15km/h.

 

[amberwolf]

And here I thought pedal power was just like 200w.

Average, maybe sustained, but peak can be a LOT higher--people break chains sometimes with the power they put thru the cranks, and I know from doing that with motors that it takes quite a bit more power than 200W to do THAT.


Regarding wheelies, CrazyBike2 is so long that it won't wheelie or even get squirelly in front at takeoff even with 4.5KW+ in a 20" 9C 2807--but it does accelerate to 20MPH in about 3 seconds. I expect if I put that same thing on my Fusin Test Bike it probably would wheelie, with the battery on the rear rack over/behind the axle and all.

 

[ZOMGVTEK]

I'm not talking about the normal bicycle kind of wheelie. What I mean by wheelie, is uncontrollable front wheel lift under throttle application alone, in a reasonable riding position, with reasonable weight distribution. Not leaning back and yanking on the handlebars with 60lb of PB on a rear rack.

You don't need any power to lift the front wheel if you're trying. If you're talking about power requirements to do power wheelies without fuss, it's probably not 3kW for most bike setups.

 

[neptronix]

You have an extended swingarm, and that's working against wheelies
That motor won't really wake up until you start dumping some serious current into it though.

My HS3548 isn't lively until about 70A in a 20" wheel ( more like 21" though ).
Give it higher voltage and it will have better torque too.

I dunno what it is about these motors though, they seem to not put a lot of power to the ground. But that power doesn't go to heat. I really haven't found out where the power is going to be honest!

 

[veloman]

Wheelies are a product are numerous variables. Power or torque being only one of them. Your position of the bike has a big influence on how hard/easy it is to wheelie. I can do small wheelies on my 8t Mac without only 1300watts at 20mph if I hit the pedals hard and pull up a little with WOT. My position is not very upright either.

 

[izeman]

... My HS3548 isn't lively until about 70A in a 20" wheel ( more like 21" though ).
Give it higher voltage and it will have better torque too.
I dunno what it is about these motors though, they seem to not put a lot of power to the ground. But that power doesn't go to heat. I really haven't found out where the power is going to be honest!

that's what i'm really talking about. i'm not really interested in doing wheelies (i ruined too many trousers and had too many wounded knees by doing that in my youth). i wanted to describe how the bike behaves when you go wot from a full stand. i thought that there would be massive torque (ebikes.ca simulator says 120nm at zero rpm), but i don't feel it. lift off is really tame and slow @2.5kw (this is what i planned the bike to set to). the bike becomes lively when i raise that to 45-50a. still nice, but at least you can feel there is "something".
this is my first DD motor, and i was using several mac/bmc and other geared motor before. those are more lively with only half or a third of the power.
and now i want to find out if i did something wrong, or if this is just as good as it can be. or maybe i'm just used to too much power yet

 

[neptronix]

That's exactly how i felt when i first fired up my HT3548, which admittedly is a fast motor not known for it's torque.

The magic pie in a 20" bucked me off when i first tested it on 33a/57v and had pretty brutal torque to 20mph. Admittedly, it's a torque wind which is totally different. But it seemed to put a lot of the power i fed it into wheel energy, more so than my MAC and 9C.

The MAC on the other hand does have a pretty linear relation of how much power you put into it VS how much you get out.

But my 3548 is just a slug and didn't wake up until i fed it 72v/60A. It took feeding it 72v/90A to get that 'WOAH' kind of acceleration that the magic pie had on lower amperage.

By the way, i am running a 12FET and have the amps cranked up that high. It's OK to push a 12FET that hard for short periods of time, but don't go climbing hills at 80A, lol...

Another thing i notice is that the cruising wattage is quite a bit higher per speed on my MAC. I can get similar efficiency to the MAC if i pedal along at lower speeds, say 15-25mph. This is a used motor and i thought maybe it was demagnetised by the previous owner, but the unloaded kV is 100% spot on to what ebikes.ca says it should be, so .... ?

The cruising wattage seems higher than what i saw on my magic pie and 9C/MXUS too.

 

[izeman]

... But my 3548 is just a slug and didn't wake up until i fed it 72v/60A. It took feeding it 72v/90A to get that 'WOAH' kind of acceleration that the magic pie had on lower amperage.

By the way, i am running a 12FET and have the amps cranked up that high. It's OK to push a 12FET that hard for short periods of time, but don't go climbing hills at 80A, lol...

90a into a 12fet? wow. that's a lot. i will set mine to 45a and 120a phase, and see if i can life with that. i think it would be no problem to run 60a through it for acceleration, but the problem would be to limit it while climbing hills. then on the other side: the faster you go up, the sooner you are there, and the shorter is the stress on the controller it's more fun as well. i think those controllers can take more than we think. just watch them closely and don't let them get too hot.

 

[Ypedal]

If you get the right, and big enough controller, the motor should melt first while the controller stays warm at worst. if your motor is not getting over 50 celcius, crank up the power.

edit " could line it up to another , known to be 500w and compare results if you got anyone else around or more than 1 bike.

 

[electr0n]

I just threw my HS3540 into a 20" wheel and set battery current to 65 amps and phase to 140 I think. I'm using a bike meant for 26" wheels, running 26" front and 20" rear. I have to be really careful with the throttle, it's touchy. I don't know if I can pop the front without trying yet, but I'm after acceleration anyway and it feels quite a bit more responsive in the small diameter wheel than the 26" I had.

I'm afraid to give it full throttle from stop since my dropouts are rounded out and I'm just testing out some do it yourself torque arms and don't want to push my luck too much yet. I almost slammed into a tree by accident while testing yesterday, touched the throttle a little harder than I wanted and smashed into a snow bank luckily

 

[neptronix]

I just threw my HS3540 into a 20" wheel and set battery current to 65 amps and phase to 140 I think. I'm using a bike meant for 26" wheels, running 26" front and 20" rear. I have to be really careful with the throttle, it's touchy. I don't know if I can pop the front without trying yet, but I'm after acceleration anyway and it feels quite a bit more responsive in the small diameter wheel than the 26" I had.

A 20" wheel on a bike made for 26" is always going to want to lift up on launch, that's the crappy part of short wheelbase mountain bike geometry. I found this out the hard way with my magic pie race bike build ( see my sig for the link ).

Move your seat as far forward as it goes, position your handlebars as far forward as they will go as well, and lower the phase amp to battery amp ratio a bit to help cut out the initial kick. It also helps to run 130-150mm cranks to prevent pedal scrape, and maybe even a 24" wheel up front to even out the geometry. a 2.5" tall tire ( whether it be moped tire or bike tire ) will help even out the rear as well. That's my advice to you if you want to do the whole '20in wheel on a mountain bike' thing.

I'm afraid to give it full throttle from stop since my dropouts are rounded out and I'm just testing out some do it yourself torque arms and don't want to push my luck too much yet. I almost slammed into a tree by accident while testing yesterday, touched the throttle a little harder than I wanted and smashed into a snow bank luckily

Oh for the love of god, get some proper torque arms - no - plates, ASAP. I rounded out the dropouts on 3/8" thick cromoly steel plates pushing my HS3548 ( the lowest torque motor in the 35mm Crystalyte H series ) to 6kw peaks. I now have 2/3rd of an inch thick steel holding the damn thing up now :lol: don't roll the dice with your rear dropouts on high power. I don't want to see any of you on here die over not putting a 1lb of extra metal on the back of your bike.

 

[izeman]

well. this is the bike i'm talking about. as you can see, it's got a longer wheelbase, and same wheels front and rear.

 

[Ypedal]

holy smokes.. lower that seat, or get some handlebar risers.. actually .. both maybe.. but with the battery pack on the handle bars like that, it's gonna take more than 3kw to make it snaky

 

[izeman]

holy smokes.. lower that seat, or get some handlebar risers.. actually .. both maybe.. but with the battery pack on the handle bars like that, it's gonna take more than 3kw to make it snaky

nope. i'm 192cm or 6'3 tall. i like the seat at the same height as the handle bars. may look different, but this may be the point of view, and the rear wheel is raised from the ground (maybe not that obvious if you don't look very close). but i will buy a handle bar with 3cm/1in more rise, as the brake levers interfere with the battery box. i will have to shorten the cranks by 4cm/1.5in anyway.
i know this bike looks a bit weird, but it's really cool when you ride it.