Certified FOCBOX Suppliers | Get Focbox Unity

Comparative claims in controlled testing


#1

The e-skate is missing some standards here…too many commercial claims without context or benchmarks. I think the solution is controlled testing with the proper equipment. Mellow and Inboard both have testing rigs…Mellow has said that theirs will be used not only to test their build, but also measure the claims of other boards.

Math is great, but can only get you so far. Does anyone else out there have testing rigs/dyno’s?

I’d love to see numbers like:

  • with 70kg load, can reach 44 kmh on flatland, and maintain for 2.5 hours within normal operating termperature of xx C.
  • with 70kg load, can start from 0 kmh on 10% hill, reach top speed of 30 kmh and maintain until battery depletion within normal operating temperature
  • can brake 100 kg load on 10% downhill in 10m :wink:

I feel really sad for mellow boards!
#2

all they (inboard) need to do is make a video of it going up a hill… the real world is a pretty good test


#3

Sorry, I’m all about the scientific method.

No, but really, my real reason is to see how each matches up against the others. The comparative video you did with a Dual and 1WD Raptor was nice. Either side-by-side or in the same situation with same rider.

They’ve all done videos of boards going up hills. Not convincing. The run-up is often cut out, they go up in a diagonal, or they use the skinniest guy on the team…


#4

i have not seen a decent hill climb from inboard or mellow


#5

However necessary, I have to say I agree to @onloop for testing. Scientific method is a matter of justification for getting numbers. Eventhough all the scientific test are successful and the numbers are okay, the purpose of those test are for end users are for real life applications. It’s a good test, but I doubt it will happen and as end user I really don’t care much as long as it works.


#6

Eboard landscape is changing quickly. I’d like to see gizmag or some other publication do an updated comparison. Ideally a comparison that combines scientific testing with real world/real conditions. Same type format you’d find in a car or motorcycle comparison. I am tired of seeing videos of a 160lbs dude roll up a slight incline as supporting evidence of a boards hill worthiness.


#7

But manufacturers/sellers do put out numbers wattage being the biggy. But it’s not a standardized test and they don’t even say continuous power or burst. People latch onto the number like it means something but it’s obviously bunk in most cases

No one wants to run a bunch of motors to the point of burning them as a test of max power but it wouldn’t be hard to make a valid assumption based on the motor temp at different wattages put in and conponent’s abilities. If there were real numbers put out we could know if it would get up a hill with a certain weight or not. We can’t compare anything really


#8

the numbers mean nothing… they can easily be made up…even if they were perfectly accurate it still doesn’t tell you shit… real world testing is the ultimate test.


#9

Sorry but real world testing are also numbers : How fast you can climb this hill, max speed, etc …
Refuting all numbers does not make much sense to me …


#10

If they were accurate, and real, then they’d tell you everything. A real continuous wattage test.

Given that there isn’t a standardized wattage test, and a real world test isn’t standardized and not replicable, the next best thing, if not the same thing really…wait for it…wait for it…knowing the motor’s components and airgap. It’s like we’re on a Ferris wheel and keep coming around again.


#11

I challenge you to define “decent hill” in a way that doesn’t involve numbers. :smile:
(Know that if you give me a street address in Australia that you’re going to set me off on a rant with no end. ;-))


#12

Well thats not really possible. There are also many varieties of incline / slope. I could climb a 40 degree incline that is 30 cm long if I have 5 meter initial path to accelerate. But does that mean my board setup can climb 40 degree looking from other people assumption, probably not. There are so much variables that could make your experiment / test invalid.

For a valid laboratory test, there has to be minimum 10 trials with 3 variable factors that needs to be determined. Independent variable, dependent variable and control. Independent variables are the things that you can change, dependent variables are the result you are searching and controls are other variable that should stay the same.

Now to begin with people already have different weight and different hill. Despite of that, there are different battery type, motor kv, propulsion system and misc board construction part.

The test can work if we are only test per brand basis, ie: Raptors Dual. However once parts are being replaced, wires are changed and things are modified those numbers are not valid anymore. The difference eboard common setup safely varies about 20% better or reduced performance one with another.

And trust me no one here would bring a ruler or measure the incline slope of the hills they are about to climb. Even if you are about to buy an electric longboard, I assume you won’t do that either. And clearly if you live on a mountain, you will opt for an all terrain high gear ratio mountain board and before that going to take place, ebike would be the better option to buy. And even if your eboard setup fails to climb the hill you want, you will change your pulley / propulsion setup. Thats why if you already think of hills, better get satellite configurations. And if the gear are already maximized for torque, then kick push it like normal board.

The point here is the number are not that important. The only possible number I could think that would make sense are not hill grade but torque rating in newton meter. It’s more controlled and easy to compare motor performance. But beware that the small brushless outrunner motor we have has various torque output depending on the rpm. It’s made to deliver the highest torque at maximum speed (If I recall correctly).

Stepping back from all of the numbers, electric longboard is just a longboard made to increase coasting time and without kicking. No one buys a longboard and ride uphill.


#13

I thought this was the DIY community :flushed:.
So why do we care what manufacturers of complete boards are claiming ?
They’ll claim anything that makes their product sell.
I think if you hang around our community for long enough you’ll soak up enough knowledge and insight to debunk the claims for yourself, without some useless regulation. Just my $.02.


#14

Well, it’s a bit ironic, because Onloop himself has blurred the lines. He sells mass-produced completes. “Mass produced” is a bit of a stretch to say since he’s a one-man show (mostly), but there are models that you can choose that are made in multiple copies. Enertion is the same as Boosted and Evolve, except he sells kits and parts as well. In terms of customization, Enertion gives even less than say, Mellow Drive, because you can get a Raptor deck in all shapes and sizes as long as it’s rigid black carbon. :slight_smile:

@laurnts, we agree. Numbers can lie, but gather enough of them controlled conditions, and they tell a better story than “my board can do a decent hill.”

I do. My e-skate isn’t a longboard but my snowboard that gives the same feeling not only when there’s no snow, but when I go flat or uphill. That’s what I tell people who say I’m lazy, btw: yeah - you try pushing your skate at 40 kmh uphill.

Also, you forget the brake. I accept that I’m a perfectly irresponsible father and bad longboarder who can’t slide so can’t really bomb hills, but I love taking steep downhills while being able to control my speed. My 10 year old daughter, who can’t kick or footbrake well, followed me down a succession of 20% curves and we both had a ball. We kept the speed down low on the knife’s edge between safety and thrill.

That’s backwards. Highest torque for all electric motors is at V=0, which is why a Tesla will slaughter sports cars out of the gate, but lose ground later on. The torque curve then drops gradually until the field weakening phase, where it drops drastically until it hits maximum rpm. The beginning of the field weakening is called the max rated speed.

I agree with you that torque tells a better story than hill grade, although the latter includes a bit of legal liability in there, i.e. the product can climb steeper hills, but will probably overheat and kill your motors. Still, a easily understandable and more precise middle ground might be nice. When I just see “Climbs hill grade 15%” I assume that they mean “it can carry the max rated load up that hill for an indefinite period of time without overheat, regardless if there was a running start or from a dead stop”. I’m pretty sure though, that that’s assuming much too much.

So, back to torque. Mellow published their torque curve. It’s a calculation, which still makes it a claim, since it was done before they setup their testing rig. The fact that torque doesn’t change until 40km/h is mind blowing. You know how you have to brace yourself when hit the throttle? When I did a testride of the board, even up near 35 km/h, I’d get that exact same kick. Crazy.

Mellow torque curve: https://www.kickstarter.com/projects/1800147378/mellow-the-electric-drive-that-fits-under-every-sk/posts/1352482?lang=de

I’m curious about torque curves of other motors perform so I’ll make a new thread though…


#15

@onloop
I am sorry, but in almost every post you make you seem like more and more of an asshole. I understand that you made this forum, but when it comes to some issues (like wanting actual performance numbers) you seem ridiculously stubborn, and refuse to change your mind when there are many people saying the opposite.

Numbers do mean something, literally everything can be defined and compared using numbers. Why do you think automotive racing teams spend so much time with their motors on dynos before they even put them in the car? Its because when its on the dyno they get a hard number on how much performance they have, VS on the road it can be very subjective and there are hundreds of variables that can change each run.

yes numbers can be made up but that’s a thing i like to call fraud/lying, which is a dick move, and when it comes to selling things (such as esk8 parts) there are actual laws against it.

WTF are you talking about? If we have two boards, with accurate numbers for their performance, then it is very easy to compare them on certain aspects and decide which one is better. Like other people have said, saying a board can go up a “decent hill” doesnt mean shit. If you can say that one board can go up a 15% hill at 10Mph for 5 minutes with a max motor temp of 80°F, and another can go up a 15% hill at 15Mph for 3 minutes with a max motor temp of 90°F. Then it clearly shows that if you have long hill then you want the first one, but if you have a short hill/want to go faster then you want the second one.

I’ll give you a half point for this, you can do all the lab testing you want, but it does come down to when the urethane meets the road. That being said, if you do thorough testing in a controlled way, when you bring multiple board out to the real world and compare them. Most of the time your real world testing (if you are doing the exact same test with each one) will match up almost perfectly with the lab testing.

Sorry for the rant, but it really bugs me when people straight up refuse science and reason.


#16

I agree, when you break anything down it’s just numbers on paper, but numerical figures alone are not proof of anything. A motor can have higher effecientcy and higher torque claims on paper. But it doesn’t prove anything. Making a calculated decision from those numbers is nothing more than guessing.

Claims should be proven/tested in a way that allow untrained observers to clearly see the subject executing the claim in its simplest form. Numbers are not important anymore. Because the observer can see that test subject X completes the circuit before Y. So X is faster.

Observing the act alone is emperical evidence of a said claim.

We don’t need numbers on paper we simply need undeniable proof.

So I say, please show me videos of performance don’t tell me your numbers.


#17

I disagree with what you wrote in so many ways it hurts to click the “quote” button.

Let’s instead get back to my original post: anyone else out there using dynos to do comparative testing? If you don’t believe in them or don’t like them, this is definitely the wrong thread to comment in.


#18

Someone who has access to a good selection of motors should build this https://www.youtube.com/watch?v=hgmWhAgdb2k

i think this is my favorite part https://youtu.be/hgmWhAgdb2k?t=276


#19

So you think I am asshole because I prefer emperical video evidence over random written performance numbers…?

…this forum is starting fill up with crazy people.

So you are saying you would happily buy one product over another based on paper specs alone? You don’t want to see evidence of it carrying a load up a hill? You don’t want to see a top speed displayed on the riders phone app in real time?

Let me guess you own a benchwheel from amazon?

Wake up people! Numbers mean nothing. Video evidence is king. Even better get out and ride some eboards once in a while… do some real world testing.


#20

If you don’t use the quote function or reply to post button we don’t know who you are referring to.

“In so many ways” please explain them