What actually is the best for sliding?

Posted: 2018-09-10 in Uncategorized
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I’ve always wanted a scientific analysis of which pavement is best for sliding…which, I’ve done myself, in a non-scientific way, when I was working in an asphalt lab. But, I presume I’m one of about…oh, one longboarder in the entire country who cares about such things. Based on what I saw in the lab, coupled with my own observations after skating all kinds of roads, the best asphalt is “theoretically” a 5e10 aged about 10 years due to the aggregate content (better for sliding on) and how the binder wears off over the years.  There’s a LOT to grapple with, between the oil-based asphalt binder, and the oil-based urethane of a skateboard wheel.  So, let’s unpack this a little:

Urethane, as shown in the Bushing and Wheel posts, is a complex compound made up of chains of molecules.  It’s the result of a few chemical reactions, similar to baking bread or frying an egg…you can’t just re-heat it and mold it into something else.  You gotta chemically undo those changes, which isn’t exactly possible.  But, that’s what makes urethane so bouncy, slidey, and wonderful.

Rebound is an important aspect of urethane.  The durometer (hardness) of a urethane product, be it a wheel or a bushing, measures how much it’ll deform under a load.  Lower durometer means it’ll deform more…and, as a wheel deforms more over a rough road surface, it’ll dig into all the imperfections and GRIP!  But wait, you ask, what about those molecular chains?  Well, with a soft urethane formula, with weak chains, that’ll make the wheel disintegrate easier…which means it’ll break into a slide easier than a wheel with tougher urethane chains.  And, those weak chains are key to leaving those ‘thane lines on the road that the kiddies love so very, very much.  As far as rebound goes, that’s how fast the original shape reforms after the initial deformation…that’ll make bushings feel a little harder, and wheels feel a little faster (as the wheel deforms and squishes on the front edge, rebound helps the wheel spring back into it’s original shape on the back edge of the wheel, returning energy to rolling, and ultimately feeling faster).  Per the Wheels post (linked above) the “Great wheels” are going to be high rebound, grippy, racing wheels…something akin to an Abec11 Zigzag or a Seismic Speedvent.  And, because urethane plays into retaining the original shape, they’re typically grippier, since the durometer allows them to deform over a rough road surface, but the rebound snaps it back into shape before it begins sliding.

Confused yet?  Hold onto your fillings, man, we’re just getting started!

Wide wheels grip like a mofo…look at Abec11 Centrax, Sector9 Steam Rollers, or Nersh Money Hax.  More real estate between your feet and the road means that more urethane can deform over the road and give you, dear rider, more grip.  So, given that assumption, common sense says smaller contact patch is slidier than a wide one…yet, it’s incredibly difficult to slide an inline skate wheel. Seriously, try it sometime! Fast as fuck, squirrelly like you wouldn’t believe, and grips like there’s no tomorrow.  Comparing rollerblade wheels to longboard wheels, the bearings are the same, the spacing of the hub is the same, hell, the damn core is the same…Labeda’s big money-makers are rollerblade wheels. The first runs of Orangatangs had the same hubs that were in my rollerblades in high school (and people were PISSED at coring their wheels within 10mm of use). I know for a fact that several other longboard brands use rollerblade hubs; there was even a rumor that Earthwing‘s Slide A formula was borrowed from an inline company. So, at least component-wise, rollerblade and longboard wheels are pretty identical. The big difference is shape, which affects the contact patch and overall ride feel.  The rollerblade wheels I used were a fairly typical longboard size and duro (76mm, 80 or 81a), fairly similar to Zigzags or Orangatang 4Presidents. I hit my local hill and tried to slide the board.  I’m sure we’re all familiar with trying to force something to slide and going *TURN*TURN*TURN*HOLYSHITI’MBACKWARDS*.  The rollerblade wheels, at least on the setup I tried, simply would not slide. It was *TURN*TURN*TURN*IFELLOFFTHEBOARDBECAUSEITGRIPPEDTOHARD*   On a rollerblade wheel, the contact patch is only a few millimeters, but it’s located directly underneath the bearings (where the rider’s weight is concentrated), so there’s an immense amount of pressure under that little tiny area. Once you add a sideways component (from sliding), that’s still not strong enough to overcome the insane PSI under the wee little tiny contact patch, so it grips like a mofo…if we extrapolate that out, there’s a going to be a constant battle between the sideways pressure, the downward pressure, and the whole darn wheel oscillating, which probably means it’ll slide like a wet fart…er, not in a good way

So, if wide-ass wheels grip like a mofo, and so do narrow-ass wheels, surely that leaves the shape of the wheel to account for.  Centerset wheels are grippiest, because the rider’s weight is centered exactly in the middle of the wheel, leaving both the inner and outer lips to dig in and grip on the road.  But, sideset wheels are grippiest, because the rider’s weight is concentrated on the inner edge (as we learned from the Wheels post, that’s where the grip comes from), and the outer edge deforms to dig in and grip the road.  But, offset wheels are the grippiest, because it’s got a little flex and deformation to dig into the inner lip, as well as a lot of flex and deformation to dig into the outer lip.  Buuuut, centerset wheels slide the best because the inner and outer lips deform equally and lift up to shed urethane nicely on the road, with the added benefit of being able to rotate the wheels to ensure even wear.  Buuuuuuut, sideset wheels are best for sliding, because the rider’s weight is only concentrated on the inner edge, leaving the rest of the wheel free to glide sideways over the road surface.  Buuuuuuuuuuuut, offset wheels are best for sliding because there’s a little give in each direction, allowing the wheel to dump urethane off of each lip.

Now, where does this leave us?  If every shape of wheel on the market is simultaneously the best and the worst for sliding, how can you know if the wheel you’re looking at is good for sliding?  The answer, not surprisingly, is rather complicated.  But, it’ll help to look at it from the opposite point of view:  Identify what makes a grippy wheel, then eliminate those characteristics to find a slidey wheel.  Grippy wheels are typically (not always) offset or center set, with sharp, machined inner and outer lips, and are made with a long-chained, high-rebound urethane formula.  High-rebound urethane (grippy) is brightly and uniformly colored, while low-rebound (slidey) urethane is a little more subdued, and maybe even a little milky looking.  In Abec11’s line, their Reflex stuff is high-rebound and grippy as hell, identified by bright lime green, lemon yellow, or atomic orange; whereas their Classic urethane in green, pink, or amber, is almost translucent.  Sector9’s Race Formula is high-rebound, and available in bright yellow, orange, or blue; whereas their classic Ghost Thane is very faint, Butterball or Skiddles formula has the same milky quality as classic Abec11 ‘thane.  Orangatang’s purple and yellow offerings are higher rebound than their orange 80a urethane, which is why the 4President and InHeat wheels don’t work as well as they should in 80a (the shapes are grippy as hell, but the urethane formula is slidey)…80a 4prez’s are the only longboard wheel that I’ve ever experienced understeer on, where the back of the board wants to turn, but the front keeps going straight.

And, onto durometer, as though this blog post isn’t convoluted enough already.  Generally speaking, lower durometer (being softer) will grip harder, and a higher durometer (being harder) will slide out easier.  But, when a wheel is too soft (below 77a or so), it’ll just deform and dump ‘thane…meaning, that it’ll slide easier.  On certain perfect surfaces (such as a smooth sidewalk, or a manmade skatepark), a higher durometer (85a or above on a sidewalk, 99a or above in a skatepark) will hold its shape against the perfectly smooth riding surface and grip hard!  When you get a rough surface, the hard wheels will bounce and glide across the surface.  The “sweet spot” for soft wheels is between around 78a and 85a…below that range, you’ll get the urethane dumps and lose grip, and above that range, you’ll get the skidding and sliding.  Between 86a and 94a, wheels are too soft for perfect surfaces, yet too hard for imperfect surfaces.  95a and above is great for ditches, street skating, park skating, and downhill techsliding.

A wise man once told me “If you can ride it, you can slide it,” which is absitively, posilutely true…but, there are myriad options of wheels out there that’ll make it easier on you to slide.  The most important thing is experimentation, and finding what works for you.  Longboarding is still relatively cheap, so save your lawnmowing money and buy a few sets of wheels.  I can’t tell you which specific product to buy, as there are SO many other factors that we didn’t even explore here, that’ll impact grip/slide characteristics.  Wheels are important, yeah, but they’re a small fraction of the chaos that is a longboard.  So, take some of the general guidelines I’ve set forth above, and attack the skateshop with an enthusiasm unknown to mankind!

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