@professor_shartsis Thanks for the data. That certainly makes sense. We’re printing out a large configuration of wheels and looking at the sensitivities ourselves.
Is it ok if I reach out to you and you can take a look at our test plan? I think we’ll start testing on the weekend of the 10th when Andrew finishes the batch of prototype wheels. Our goal is to assess the sensitivities and try to hit the characteristics that people want in these wheels.
re: If we made a wheel that was more comfortable and had a higher top speed capacity, what would you NOT want to lose?"
B) Acceleration <-- this one. unfortunately basic laws of physics prohibit this option.
otherwise:
D) Range… this could theoretically be possible if you can drastically reduce the rolling resistance
@professor_shartsis This is pretty compelling data at steady state. What kind of wheels were you using for the 80mm and 100mm? Can you share the model and durometer?
I think that would help us understand it a little more on how the sensitives affect performance.
This is great testing. Thanks so much for sharing the data.
@Jmding Prof’s data is very good and he has more data than we currently have on wheels. This is a great, isolated resource. I think there is so much in the dynamic testing that will matter just because (on the small data sample from the survey so far) that people are more interested in dynamic performance, such as ride quality, grip (I think this could also mean handling in automotive terms, right?), etc. rather than the original thought which was just a land speed record wheel.
So this new finding will change how we test and develop.
Thanks for your feedback on points 1 and 2. It makes a lot of sense. We’re trying to build a relationship with people in the esk8 community. We anticipate people will really hate us (maybe mostly @b264) in the beginning. If we continue to develop, capture data, and try to align the data with what people are saying in the survey, and show every step of the way then maybe we’ll have a good product. It’s as much of a marketing experiment I’ve always wanted to do rather than just develop in stealth and release.
Contact patch: Currenly thinking of 40mm, but we’re making multiple iterations that are a little wider. We’ll be doing dynamic and static tests according to this (Work in progress) sheet:
Hoping to start testing on the weekend of the 10th when we get all the proto done.
@professor_shartsis Certainly, there is no wheel that can have both great acceleration, top speed, ride compfort, etc. It’s either ride comfort or speed, but you will be difficult to have both.
Also, certainly we can be wrong in our engineering estimates and experimenting with sensitivities as we go. I should have changed the tone of the first post from we are making this and let us get your feedback to let us get your feedback on what you guys want in a wheel.
@Jmding Thanks for taking the time to contribute! Seems like we are pretty aligned.
@professor_shartsis Yes, the acceleration is exactly equal, but the difference between the two models is 27 newtons thrust. I think I have to be a bit more careful on my word choice, but in reality, I think that having bolt on performance upgrade of speed with 27 decrease in newton might be a good trade off.
Either way, we have to make it and test it.
This is all the time I have today for posting because I have other obligations, but I’ll post up again tomorrow. Thanks for all the contribution. I am only 58 posts in so far of the total 119.
40mm contact patch isnt anywhere near wide enough.
I also feel this is absurd lol.
I want wide wheels like that for belt drive so badly.
LoL I don’t hate you, I just want to make sure you genuinely care about electric skateboarding because until now I’ve only seen some marketing stuff you keep trying to pass-off as real despite being told and shown numerous times by numerous folks that it’s factually incorrect.
When you genuinely care about electric skateboarding and have done so yourself for an amount of time, I will encourage you to innovate – as long as parting Boosted riders from their cash is not your primary goal.
So far, you’d shown that it indeed was, and that you aren’t an electric skateboarder.
@dth2m5 when you increase the wheel diameter to increase top speed there is a very simple formula for how much acceleration you will lose compared to the original wheel…
for example suppose you make a wheel that has a diameter and theoretical top speed that is 1.25x as large as the original diameter… you’ll have 1 / 1.25 = 0.8 times as much acceleration.
if you can also decrease the moment of inertia of the larger diameter wheel…
because the wheel moment of inertia is somewhere between 1/1000th to 1/10000th of the overall vehicle inertia including the rider then add somewhere between (best case) about 0.001 & 0.0001 to the new factor of change of acceleration value:
0.8 + 0.0001 = 0.8001 0.8 + 0.001 = 0.801 ^0.801 is the best case acceleration change factor w/ 80mm → 100mm (with drastic reduction in moment of inertia)
in other words even if you drastically decrease the moment of inertia of the larger diameter wheel at the same ground speed, you’ll still have less acceleration roughly proportional to the inverse of the factor of diameter increase.
another way to think of this is to suppose you simply decrease the moment of inertia of the original size 80mm diameter wheels. the acceleration benefits will be real but likely imperceptible… roughly somewhere between 1.001 to 1.0001 factor of acceleration increase and 0 top speed increase.
in order to truly demonstrate how your wheels are superior, you’ll have to compare them with wheels that are the same diameter. for example, if you are making 100mm diameter wheels, how do the riding characteristics compare to other 100mm wheels on the market? there won’t be any benefit in top speed to proclaim, so what else can be improved?
^& here is an example of a forum member ( @Ouch ) upgrading to a larger diameter wheel but also increasing their gearing ratio to (I assume) approximate their original top speed and acceleration but with the benefits of a larger diameter wheel.
97mm / 83mm = 1.16x diameter increase 2.8 / 2.66 = 1.05x ratio increase (1/1.05) * 1.16 = 1.1x top speed increase 1/1.1 = 0.909x acceleration/thrust decrease
had he chosen a 46T wheel pulley instead to go with the 97mm wheel, he’d be quite close to the original top speed and acceleration, but with the handling benefits of a larger wheel diameter.
shout out to @professor_shartsis s patience and basically doing research for other people, I wish the professors around me would be more like you 
So far, you’d shown that it indeed was, and that you aren’t an electric skateboarder
Engineers!
uh oh i smell a change in the attitude here… lets not revert to our primal states
… armadillo enclosure… cough cough
Flywheels have a 44mm contact patch and even that seems small. They grip well enough but it does make crossing railroad tracks a bit more difficult if you don’t have a large diameter wheel.
Dammit! Where is my dick soup meme?
When I said absurd in my last post I really wanted to say just skateboarder… electric would be lost without analog and actually feeling the difference in wheels … but i kept it as nice as possible with one word. absurd.
not all flywheels, and again 40mm on a 100mm+ diameter? nonsense
is that a dick in a pot? or a dick stirring the pot… lol