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| Wheel Reviews (7945 Posts)
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Speed with heat
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On 12/28/2000
Duane
wrote in from
(140.239.nnn.nnn)
Reply to hugh... There is no question that cross-linked rubber becomes faster with heat.. the right amount of heat. About 180F seems to be about right. It is difficult to keep the rubber hot once you start rolling. These comments apply only to cross-linked rubber, not urethane. Urethane becomes slightly faster with a little heat, perhaps 100F. Also, warm wheels tend to warm up the bearings, which increases clearances and reduces the oil viscosity, both promoting speed.
Overheating cross-linked rubber will make it sticky. permanent damage is done at this point. This experience with rubber comes from the competition which is held at my alma mater, which involves fully enclosed, low drag vehicles (like a high-tech soap box derby). Much effort was put into wheels for speed. For example, the same rubber tire would roll the downhill portion in about 46 seconds at room temperature; this number could be reduced to about 44 seconds with the wheels heated prior to the roll. This doesn't sound like much, but 2 seconds at 35 mph is a huge gap. Urethane or 12" pneumetic wheels (pumped to 300 psi!) could never match heated natural rubber for speed. The rubber wheels were aluminum hubbed with about 3/4" rubber depth, profiled similar to in-line skates but a little wider. Higher or lower rubber was slower. This competition has been held since 1916, so people really know what they are doing. Companies like Goodyear and Kryptonics have been involved over the years in making fast wheels specifically for this race.
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Duane's Pic
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On 12/27/2000
Chris Chaput
wrote in from
(63.168.nnn.nnn)
I just want to see the picture!
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rubber o'er thane
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On 12/27/2000
hugh r
wrote in from
(205.216.nnn.nnn)
Duane,
While I do agree that rubber has it all over urethane in a wet environment... I would be interested in hearing more to back up your statements indicating that rubber becomes much faster when heated.
I have had the opposite experience with heated rubber. I have found that rubber gets "stickier" when warmed and the only thing I have found to increase is traction. Which does equate to more speed, but not because the rubber is faster.
The comments concerning how wheels are made are beyond my scope of knowledge. But something doesn't sound quite right with your position.
I am interested in hearing some of the details... thanks, HR
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Real rubber versus urethane
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On 12/27/2000
Duane
wrote in from
(206.133.nnn.nnn)
urethane is death with water present, absolutely no traction. In general, urethane is more durable and cheaper, but cross-linked rubber like on auto tires can be made faster. If someone had the money, or the interest of a rubber manufacturer, you could make a hubbed rubber wheel that would absolutely smoke any urethane wheel. Also, real rubber responds to "treatment", such as soaking in toluene or xylene to increase the rebound, and thus speed, dramatically (short-term). This does not work with urethane. Also, real rubber gets very fast when heated, urethane only improves a little. But (big but), urethane is poured under low pressure into cheap molds, whereas rubber must be injected at high pressure, into expensive molds, and put through a cross-link heat cycle precisely to get the best results. Those fools who were cooling their urethane wheels at recent competitions just made them slower, until they warmed up. As an aside, I have a great pic of Chris Chaput skating my half-pipe ramp in MD in about 1980.
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rain Wheels
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On 12/26/2000
Mike
wrote in from
(194.230.nnn.nnn)
Phil, sure they use PU on rocket powered cars but this cars only go straight and the wheels are designed for speed only! If you need gripp, i can tell you for sure rubber will always be better. It`s a physical thing !
But i agree that with new methodes it will be possible to mix the tow, like that you will have grip and speed.
mike
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rain Wheels
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On 12/26/2000
Mike
wrote in from
(194.230.nnn.nnn)
Phil, sure they use PU on rocket powered cars but this cars only go straight and the wheels are designed for only! If you need gripp, i can tell you for sure rubber will always be better. It`s a physical thing !
But i agree that with new methodes it will be possible to mix the tow, like that you will have grip and speed.
mike
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rain wheels
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On 12/26/2000 rene
wrote in from
(216.101.nnn.nnn)
scabs,
Our factory has been making industrial urethane wheels for forklifts and such for years, traction is no good on urethane with water/oil/liquid repeat does not work, rubber is much better. I could ask our chemist why but I don't think it matters...for rain riding try the new Bomb from extreme that will most likely work well!
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DILEMA
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On 12/26/2000
LEO
wrote in from
(146.18.nnn.nnn)
i gave my bro that lives in NYC $70 to buy the randals 2, they cos 50 bucks, with the rest 20$ and a little bit of my bor i hope, i want to buy:
-option 1: HELMET
-option 2: HARD WHEELS? (hmmmm... i have 3 soft-middle pairs)
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Urethane wheels
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On 12/26/2000
phil
wrote in from
(205.188.nnn.nnn)
Mike, the reason that they dont use urethane on cars is because of the price. The only time when urethane is used is when it is on rocket powered cars on the bonneville salt flats. The wheels cost approximatley 2000 to 5000 dollars each. They need to be wound onto the wheel...eg. there is a string like substance which is the urethane and us wound on to the hub.. which is made out of titanium and can stand up to tremendous heat on the salt flats. these wheels were used to the Trust SSC. The worlds fastest car today
Phil
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Rain Wheels
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On 12/25/2000 Scabs
wrote in from
(209.86.nnn.nnn)
Hey Mike,
I question your reasoning. For discussion sake, I doubt urethane isn`t used on autos purely do to high costs. Since both rubber and urethane are basically petroleum compounds, it`s just a matter of adjusting durometer and resiliency (bounce). Keep in mind that most rubber tires are hollow and urethanes are solid. There are far too many factors such as size, shape, durometer, resiliency...etc to factor one compound out over another.
And in closing, my truck (full sized Dodge Ram) slides too easily on newly wetted roads where the oil has just risen. Maybe a softer urethane with grooves would improve the braking? I saw an article in one of the car mags that has a concept car with urethane wheels and 2 pc rims. Will that be our future?
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OJ
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On 12/23/2000 Rooney
wrote in from
(152.163.nnn.nnn)
Ebay ,lots of used and NOS OJS . prices vary
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OJ wheels
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On 12/22/2000 James
wrote in from
(205.188.nnn.nnn)
does anyone know if they still make OJ wheels and where I could find them?
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Rain Wheels
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On 12/22/2000 Mike
wrote in from
(194.230.nnn.nnn)
i just have to agree with René, that only Rubber realy has grip, otherwise cars would be equiped with PU a long time ago !
Mike
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Kwiksplits Gripped!!
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On 12/22/2000
Ben
wrote in from
(63.202.nnn.nnn)
Go figure.
A friend and I were goofing around with a Powerboard and the Pumpkin on a set of five empty tennis courts in the dark tonight. I rode the Pumpkin with M-80s for about two hours on and off, doing some slides and a lot of tight turns. I got nice, controlled slides.
We came back to my place and I replaced the M-80s with a new set of Kwiksplits and these cool 76mm 78a rollerskate wheels with watch batteries and LEDs in them - the LEDs flicker on and off for about two seconds every time you jostle them. The whole setup was virgin - the wheels still had flashing along the center of the tread, brand new bearings etc.
I was curious to see how they compared, so I went back. I don't think they pumped as well, probably due to lateral friction as they turn. I don't think they were as fast either, maybe because the bearings weren't broken in. They did look cool as hell in the dark, though - pretty outrageous. Three colors of LEDs, across eight wheels, must see.
They did grip a hell of a lot more than I thought they would, and I actually had a harder time sliding them than the M-80s. The M-80s, once they broke free, would slide controllably. These were really hard to break free and hooked up again much faster - not fun to slide because it's so hard to get there and they stop sliding so fast.
I looked at the contact patch later when I got inside, not more than a quarter-inch wide. At least the flashing got erased.
Don't get me wrong - with conditioned 80mm 74a hockey wheels I thought they slid out too easily. But with these new wheels I don't see grip as an issue anymore with the Kwiksplit.
So, if you disagree, GO RIDE THEM AGAIN and try to slide 'em. With virgin non-conditioned round profile 78a wheels they really hooked up impressively. And they still climb bumps better than any normal wheel of the same height.
Lastly, I got those bitchin LED wheels for $40 a dozen and the board looks insane from 200 yards away!!! I have an eight-wheeled vehicle with 24 LEDs flashing. It is really cool looking and a great idea just from a safety perspective (said the man with the taxi-print on his forehead)
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slip slop slap
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On 12/21/2000 lindsay
wrote in from
(202.37.nnn.nnn)
Yeah, especially in sunny CA where it never seems to rain, everyone drives everywhere and the oil just accumulates!
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rain wheels...
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On 12/21/2000 rene
wrote in from
(216.101.nnn.nnn)
maybe u guy's are on drugs....urethane is slippery when wet end of story...regardless of type of compound, we tried years ago mixing rubber into the urethane so it would grip...the basic problem on asphalt is that oil comes up when it rains and that's the problem not as much the h2o but the damn oil in the streets...ever skated inline in the rain, it sucks...rubber sticks to oil as urethane won't
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rain wheels
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On 12/21/2000
Lonecore
wrote in from
(212.243.nnn.nnn)
maybe it's just the compound of my inline wheels. Bu they aren't so slim, because they slide down fast and become wider.
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Kwik grip
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On 12/19/2000 Herbn
wrote in from
(216.107.nnn.nnn)
maybe the streets are grooved and the skinny wheels fit in the grooves:)
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Kwikspit are grippiest???
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On 12/19/2000
roger
wrote in from
(198.206.nnn.nnn)
Lonecore, did I understand you right? Kwiksplit are grippiest in rain? I could see how slim wheels are less likely to hydroplane going through a puddle, but with such small contact patch for traction I would expect them to be super sliding all over the place.
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rain wheels
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On 12/19/2000
Lonecore
wrote in from
(212.243.nnn.nnn)
I have experienced that the two best (=grippiest) wheels in rain are old krytos (the lime green/orange ones) or Kwiksplit. but it also depends on the street surface, and I thnk our Swisss asphalt is different than the american streets.
Lonecore
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CX-66
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On 12/17/2000 Pre-School Rider
wrote in from
(209.198.nnn.nnn)
Alex,those wheels came out in late '79 early '80.I can't find the durometer rating for those,but my foggy memory says that Krypto kept their 'color' rating in place for those,at least for the first year.That would make 'reds' 78A,Blues 88A,Greens 93A,but the Yellow ones(?),I don't know what durometer they were,but I'd guess in the mid-80's or so.CX's did go to other colors(Black for instance)that didn't correlate with the usual color=hardness that Krypto had used,and the second year run('81)they came as either medium (88A) or hard (93A)in either CX 64 or CX 66.They're a great collector wheel,but I'd ride them just because they roll really well!
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rain wheels
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On 12/17/2000
Scabs
wrote in from
(209.86.nnn.nnn)
I`ve been thinking of doing something like the z-wheels myself. I fiured I`d take an old set of Kryptos and measure where I wanted to put the grooves and mark it with a magic marker. Then with the wheels mounted on the board (turned up-side-down), I`d take my dremel tool and carve out the grooves. It should only take a little hand pressure on the wheel to allow the dremel to do it`s thing.
Any other suggestions?
Yeah, I know, gloves and protective eyewear...
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RED CX66 KRYPTONICS WHEELS
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On 12/16/2000 ALEX
wrote in from
(195.92.nnn.nnn)
Hello out there,
Can anybody help me?!!
I've just recently aquired 3 sets of CX66 Kryptonics Red
Wheels .
I'me unsure as to their durometer , but they feel/ride
great on my newly aquired fibreflex longboard .
Can anybody tell me how old they are.
If it helps both edges of the wheels have coned sides .
I'me also trying to complete an old - skool set up , which includes , a set of ACS - 650 TRUCKS , G&S Oaktail and
I'me trying to find a set of Kryptonics from the 77' - 78' era ( preferably 60mm clear green ones ) .
Where on earth do I look for the wheels ? .
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rain wheels
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On 12/16/2000
STEVIE B
wrote in from
(193.113.nnn.nnn)
Back in the 70,s Dunlop the tyre people had a wheel for riding in the rain,it was quite wide and had a half pu/rubber profile however there mistake was to put the rubber on the outside of the wheel as they coned a matter of days.
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grooves on wheels
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On 12/15/2000 Pre-School Rider
wrote in from
(209.198.nnn.nnn)
Roger,back in the late '70's/early '80's there was a pool wheel from Z wheels(the Z-Groove)that had gooves in it to channel water out from under the treads(an occupational hazard of sessioning empty swimming pools)and they worked pretty well.If you're riding through standing water(not just wet spots),rain grooves may be a good thing to have.It's nothing that a quick trip to the lathe can't solve.
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