Hub Motor & Urethane Riding Qualities

If you go back and read my last post on the “car” analogy, you’ll see that we agree. Racers use what wins races. Period. They don’t get “style” points for the size of their rims. The point is, when performance matters, you use what performs. Similarly, racers in downhill and street luge and slalom skateboarding have all found that having a lot of urethane on wheels works. Larger hubs are used sparingly as they tend to suppress the amount that a wheel can deform and contact the asphalt. You can have a super wide contact patch but if the wheel is on edge (as it tends to be because of the lean-steer nature of a skateboard when cornering), it can’t provide very good traction. Cars are also trying to maximize the amount of contact and down-force on its wheels, and the more power that you provide your wheels with, the more important it is to provide traction. That’s true both for acceleration and deceleration. I seems as if most race cars have figured out how to effectively cool their brakes so I’m not sure why the “bigger rims / bigger brakes” approach provides much value. In other words, if the tire is like ice, why do you need a better brake when it slips so much that can’t stop a car?

Unlike the big rims in low profile tires, hub motors “free-roll” more and provide less braking so you can’t put “less braking” as a con to having high profile skateboard wheels. Since you can have a lot of urethane with EITHER a direct drive system (Carvon) or belt/pulley/gear reduction systems, I’d say that’s a PRO.

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I see… I see… How much torque per speed you think, it will be able to produce. Because I’m also looking in a different technique to provide much more speed per torque than supra conductor… I thinking, that if I coated teflon over regular regular wheel or even hubs, I could reduce the friction coefficient by at least 5 torque per speed which should be more than enough to propulse me over the 11 torque per speed require for sonic speed…

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How are you calculating sonics per torque propulsed? Just remember the 5th law of thermal hammocks: The angle of the dangle is inversely proportional to the heat of the beat.

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… and certain wheels tend to win certain races for different reasons.

… and it’s not always more urethane

Not always, and I know this is nothing new to you:

In Downhill these days, almost all races are won on cored wheels with less urethane depth.

At Maryhill, for example, some might argue that an 80mm Kegel (cored wheel / less urethane depth) is a better choice than 83mm Centrax (larger wheel with way more urethane). Less urethane depth can equal greater roll-speed, and a harder / wider core supporting the lips can equal more traction. Maryhill likes roll-speed and traction.

More technical courses (that require sliding / pre-drifting) are also almost always won now on cored wheels with less urethane depth. But for different reasons: Smaller wheels tend to me more desirable for accelerating and decelerating. So lets compare a couple: Take a 75mm Big Zig HD (36mm wide core X 59mm wide core) versus a Venom 76mm Cannibal (46mm wide core X 62mm wide wheel). Big Zig core covers 61% of the width of the wheel. Cannibal core covers 74% of the width of the wheel. Some might suggest because the lips are supported more on the Cannibals, they pre-drift more predictably. They also might offer greater traction around corners, and slow down quicker, due to less deformation (more leverage) for both.

The above completely leaves out lots of other factors (core diameter, lip shape, durometer, formula, etc. etc.), and less thane depth is always going to equal a rougher ride. But winning races isn’t about comfort. Traction going around a corner is different than traction starting from a stop and going in a straight line. It all goes back to trade-offs based on the course. Drag wheels don’t win Indy races and visa versa.

As for Electric Skateboards, we all want different things. For me hub-motors will never be an option, for many logical reasons, but that doesn’t make them wrong.

If all you care about is how something looks (for example), and you think hub motors look better, they’re for you. Put it on your wall and be happy. Comes down to what you care / know about… and what you will never know won’t hurt you.

If you just stand there pressing a button barely turning, you’ll never appreciate the nuances of wheels.

Keeping you fillings in is another story…

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Actually I completely forgot about the 5th law… But still by following the precepts of 1Sonic equal the scare root of (e=mc2)3,1416 and that one speed is equal to 1/11 of a sonic bang, and one torque unit is equivalent to (F=q(E+v*B))*Erpm per feet, than you can elaborate that 1 speed per torque is propotionate to 100 plus one velofast

As a skateboard builder you should make sure you tighten your nutz. Maybe if you spent more time building eboards, instead of playing shop, you would have more experience? :kissing_heart:

The Raptor 2 has more than 19mm urethane on the outside, more urethane than the world’s fastest wheels, dampening ain’t a problem.

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The back and forth is always fun. But, couldn’t you have just posted that photo instead of all the dragsters, indy cars and street skates?

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I guess that is the real difference between a builder and a marketing “guru”, working in my shop does feel a lot like play! I am sure you would be miserable, manual labor is beneath you right ;). Please don’t let me stop you from expressing your contempt for those who are passionate about building boards and sharing information.

Back to the topic of ride quality. Please explain how your hub motors have a superior rider comfort when compared to a quality longboard wheel, that is what you are trying to say isn’t it?

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Whoa! Is this magic? Thought your wheels were 90mm?

My 3-year-old does this kinda shite at the dinner table;

He says: “I don’t like mushrooms” I say: “how would you know, you have never tried one?”



This thread is so ridiculous, What I do love about this topic, however, is that hub motor critics are no longer trying to dismiss my claims about hub motor performance!. It’s hard to argue against video evidence.

… So now whats left to bitch & complain about? Ok, let’s talk about the extremely subjective topic of “comfort” on a product that none of you have even ridden… haha… just like 3yr olds with invalid arguments



In summary, It’s all relative, each system has advantages & disadvantages!

Here is what we know to be true

If you want to go really fast you actually don’t need lots of urethane or extra large wheel diameters or high urethane to hub ratio. Proven.

##Here is what we need to test further If you want greater vibrations dampening & comfort increase urethane to core ratio. What is the optimal ratio? maybe somewhere around 30-50% - Not Proven.

Someone needs to be the antagonist, otherwise people will get away with saying anything!


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Are you talking about the video were an evolve with 50mm motors smoked the raptor off the line?

To be fair at about 2:10 the opposite happened. This is definitely not a scientific test anyway as rider weight and ability come into play.

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The main thing we should take away from this is the fact that the evolve and boosted are using much smaller motors and are running factory settings. The evolve still proved to be similar in performance off the line. Imagine what it would have looked like if the evolve had the same size motors as the raptor.

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I wonder about that. If Jason is claiming 19-20mm of thane on his hubs. On 90mm wheels this means only 50mm is actual motor.

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Possibly, but he has already shown his stator and it is much larger than what we see in a 50mm motor. So it isn’t likely that he actually has 19mm of thane.

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It is hard to tell from the pic, but it looks like a locating bead on either side of the wheel is 19… it certainly looks to be deflecting from the caliper more than the outside of the wheel that suggests it does not have equal mass. I am surprised no one has mentioned the recent Carvon 4wd, two hub motors on one end and duel drive belt system at the other? Wonder why that was?

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When I was looking at drive trains for my build I looked in hub motors. The the fact that the urethane choices for hub motors are so limited was a real deal breaker. You just can’t over look the advantages of standardized parts. When my current wheels on my belt drive are shot I’ll have a nice choice of replacement wheels from reliable producers. When my motor blows up I’ll have just as many choices. I have my doubts about hub motors, and availability good replacement urethane. If hub motors get standardize I’ll think about it.

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I think evolve uses the same tiny-stock-standard-hobby-rcplane motors that you use?

Or did you finally realise bigger motors are better? Seems like you have found the factory that carvon uses now…?

You guys should try designing & engineering your own motors from scratch, its fun!

Off the shelf tech is holding you back.

If anyone is interested in some wheel facts, here is a chart showing wheels used by the fastest riders in the world…

Largest wheel is 76mm Largest contact patch is 68mm

The really wide wheels seem to be popular!

http://esk8content.nyc3.digitaloceanspaces.com/uploads/db2454/optimized/3X/1/7/1791ece42c8060bd483548d620ecef8b9aaa2db4_1_690x243.png

@onloop

Im also trying to wrap my head around the math here. If your wheels are 90mm in diameter and 39.2mm of that is Urethane then your motors are 50mm in diameter right? U said you are using bigger motors though so are you just refering to the stator length being larger or is there another 13mm of motor hiding somewhere?

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