I was recently talking to a skater who sent an email titled "The Never Ending Dilemma I Call Wheels" which is a genius header - that's what I really wanted to title this blog but I didn't want to bite her too hard.  But we get a lot of questions about durometers and so we ASK a lot of questions to the manufacturers and we keep asking until the often seemingly contradictory things they tell us start to agree - or at least make sense.  Here's kind of a summary of some of what I've figured out from Radar, Sure Grip, my own experience and from talking to girls all day long about wheels - and reading posts on the 10,000 !@#$ yahoo groups we're all on.

DUROMETER - what the hell is it?
Durometer is a measure of the hardness of urethane in wheels and its only ONE factor in how grippy wheels might be.  An actual *durometer* (at least the one I saw) is a little hand-held meter with a tiny retractable metal tip on the end and a gauge on the other end.  If you have a sheet of urethane (dried or cured or whatever), you roll the tip over it and the gauge tells you the durometer reading of that slab of urethane.  Its easy to fuck that up, though, because its a hand held gauge and you can make your reading inaccurate by too much pressure, too little, etc. And its even harder to get an accurate reading on a wheel shape because its round, so the curve of the wheel and the grooves can make it even harder to get right.

Anyway, other factors in how grippy a wheel is in actuality can include:

1. The formula of the urethane they're made of.  For track skating purposes, most "experts" - and skaters, who are the real experts - seem to agree that Poly BD urethane is the shit for us; funny story about Poly BD later.  Other urethane formulas include TDI, MDI and outdoor formulas, all with different properties and characteristics that make them suitable for some things better than others, but all of which have allegedly accurate durometer readings.  Then there are also clay, wood, and pretty much any other material you can make into wheels... never tried any of those, though, so I'm gonna stick to talking about urethane here.

2. The hub material & shape.  Some skaters swear by aluminum hubs, others by nylon.   Nylon hubs have flex to them when you're rolling and pushing - so that flex translates into more grippiness if you were to put the exact same urethane in the exact same shape on the same size/shape hub (one nylon, one aluminum), as well.  I prefer nylon for that reason.  Nylon hubs with holes might be even more flexi than solid - not sure on that one but it seems logical to me.  If there's a difference its probably negligable, though.  Aluminum hubs are supposed to be lighter, but I am not 100% sure on that one.  Nylon *plates* tend to be lighter than the inexpensive aluminum plates, so there are more factors in the metal hubs that have to be considered to say one or the other is lighter.

3.  Wheel/urethane shape and ratio of urethane to hub.  Another factor in shape is how much urethane there is to how much hub - ie low profile tires like race cars.  For example:
Power wheels: http://www.sincityskates.com/2nd/wheels/sg-power.html
Power PLUS wheels: http://www.sincityskates.com/2nd/wheels/sg-powerplus.html
The Plus wheels have less urethane and more hub - which is supposed to be better. I asked Sure Grip why and I remember the explanation had to do with the shape of the edge on the wheel, the amount of urethane on it, weight and a whole bunch of other stuff, but dammit, neither Trish or I can recall the exact explanation of WHY all that made Power PLUS wheels better - or more expensive (though I suspect the price is more about the polished aluminum hubs rather than the Power's treated, smaller hubs). But if anyone knows about car wheels and why racers like wide, low profile tires on aluminum wheels - I bet its the same reason- better traction.   Doh.  Sorry - at least I admit when I don't know something though, so hopefully that's charming or something.

4. The Universe.  Meaning - the weather.  The humidity.  How dirty your floor is.  What type of floor your venue has - etc etc etc.  All the obvious stuff.  So a girl skating in a humid, hot wooden rink with a grippy urethane coating in the South in the summer without A/C is going to HATE super grippy wheels and will prefer something firm.  But my team, outside at night in the cold, dry air of winter in the desert on a slippery cement outdoor track that's usually coated in dust will be physically unable to hold corners in wheels the Southern girl loves.  Meaning what's right for someone else ain't necessarily right for you.  So before you ask on a messageboard what wheels are best, ask the veterans on your team!!  The girls who've tried different wheels on your floor will probably be a lot more helpful than anyone else. 

Side note (intentional digression, in other words) - I've noticed more and more of the girls have lots of wheels depending on what they're doing - including me.  I prefer orange Tuners on grippy floors, blue Fugitives on everything else for bouting, pink Tuners for practice, and I have two sets of outdoor wheels depending on the surface (Pures if its practice and I have to sprint at a park or something, Aerobics for f-ing around).  I also have a set of hard-as-hell shitty, cheap wheels called vapor lites that I love for the skate park.

and finally, back to factors in wheels re: grippiness:
5. Durometer

So what's the real difference between 92s and 95s?  What's the difference between, say, blue fugitives - the grippiest, and reds - the firmest Fugis we carry?  That will depend on the +/- factor for that particular wheel (like maybe your blue fugitives that you think are 92s are actually 91 or 93 - and the red fugis you're comparing that are supposed to be 95s are actually 93s also), and all kinds of factors in your venue, as well, like temp, humidity, dirtiness of the floor, your skill as a skater, etc.   

So when you take all that into account, that is why wheel manufacturers are reluctant to put the durometer on the wheels, because its more like a target they aim for than a set measurement of that particular wheel.  For real, we have to trick them into telling us what it is, half the time.  Sure Grip qualifies their durometer listing with the +/- explanation, and Radar is opting out entirely lately, using terms like "tite" to describe their wheels and not letting us pin them down with durometers at all.

But factor in all that... and the smart skater will basically use the durometer as ONE way to compare wheels, rather than as a set measurement of which one will be grippier than another.

An example of how durometer can be an unreliable comparison (if taken totally out of context): 95A red Fugitives vs 95A Radar Cayman wheels.  Both wheels are on nylon hubs, similar size and shape.  But the Fugis are Poly BD - and the Caymans are either TDI or MDI (not sure which).  So the same durometer of wheels is the same but in actuality, the red Fugis are much grippier.

Which means, if you think that one step further, that durometer ratings are a good way to compare wheels of the SAME MODEL.  A lower durometer rating will be grippier than a higher durometer when you're talking about Fugitives - usually (taking into account the +/-).  But if you're comparing apples to oranges - or Fugis to Tuners, its less reliable.  And if you're comparing apples to cumquats ::snickers::,  like V-Drives to Flat Outs... well, then durometer is even less reliable because there are so many other factors to take into consideration.   

And grippier is becoming universally accepted as better in our little subculture, but that's not really always the case, either, in my opinion.  For example, I prefer firmer wheels for practice because grippier wheels wear out faster.  I know, I know - "experts" say that the grooves don't make them grippier, but I can tell when my wheels are bald because I do 8-wheel slides in the sweet spot turns!!  So no matter how many times I'm told grooves don't matter, they matter to me.  And softer Poly BD wheels lose their grooves faster than firmer Poly BD wheels - and firmer Poly BD wheels loose THEIR grooves faster than shitty, harder urethane like MDI or TDI.  So its a trade off. 

And then also, skaters call us all the time to ask for grippy wheels that won't slow them down.   Ugh...?  Well, the truth is that grippy wheels are bound to be slower in a sense - they're gripping, after all.  But what are you trying to achieve?  If you slip on every push, can you get going as fast?  If you slide out on turns or have to coast to hang on, you are probably slowing your overall lap speed.  On the other hand, when I first switched to blue fugitives, I got a lap and a half less than usual on a timed 5-minute sprint.  I was pissed.  And I was more tired, because I was pushing harder - the grippiness slowed me down.  BUT - the next week I was back up to where I was because I was accustomed to the grippiness and pushed accordingly and probably got a little stronger just from sheer stubborness and a refusal to get less laps than I was shooting for.  And in a PACK situation, I loved the Fugis right away, because I could bob and weave without sliding, taking harder hits, etc - so even though I might have been a hair slower, I was getting through the pack faster.  And that's what really counts, for me.

* One idea I see a lot of skaters (including me) interested in these days is switching wheels in certain spots.  By now everyone knows which are their "pusher" wheels, right?  If not, I babbled in an earlier blog about rotating pusher wheels so I am too lazy to do it all again.  But more and more I'm seeing skaters with grippy wheels in the pusher positions, and firmer wheels on the rest of their skates.   Its becoming more and more common and it is a really good way to solve the problem of how to get more grip without giving up speed.   I'm sure you'll see more blogs on this one as more of us try it and talk about it.  So far I love it, but for bouts on slippery surfaces (which is all we've done lately), I just make sure I have new, grooviest blue Fugitives on my pusher wheels and servicable blues on the rest.

Coming back (as promised) to the Poly BD.  I heard a funny story from Jim Ball at Sure Grip Sunday.  We were talking about wheels and fugitives and whatever, and he told us that when Poly BD wheels were first manufactured way back when, that they were stinky.  The formula smelled bad - but they were soft, so speed skaters loved them.  He said they even left a bit of a film on the track, so later heats of speed skaters were skating on the urethane the first skaters left on the track, and had even better grip.  He was telling us it got so that speed skaters would actually request the "stinky" wheels, because the smell was directly associated with that particular formula!  Manufacturers figured out how to get the stink out, but then they were forced to add it back in because the customers distrusted the non-smelly Poly BD wheels.  So they added in some extra stink to the manufacturing process!!  Heh.

Of course, while we were listening, Trish and I immediately picked up Fugitives sitting on the desk to smell them and $100 says that half of you just did the same.  Heh.  We didn't think they were smelly at all and Jim explained that they stopped putting the stink in Fugis.  But I kind of wish they'd put it back because that is FUNNY SHIT.

If I were clever, I'd write a haiku to immortalize stinky wheels right now.  But poetry is not my forte.  Sorry.