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Old January 1st, 2017, 06:03 PM   #17
Doc Sk8
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Join Date: Oct 2007
Location: Big hill on Mars
Posts: 12,120
Default Interesting list....

I'm gonna play w/ your list a bit.

Originally Posted by fierocious1 View Post
Also wheels from different companies have different recipes so grip and roll is not just about how hard they are. Lots of variables to observe.

1. Type of or chemical recipe of urethane.

This is the end all and be all of sk8 wheel engineering. It is essentially what makes comparing wheels by durometer a fools errand.

2. Hardness

Comparing advertised durometer between wheel brands may or may not tell you anything. Comparing between the same brands by actual measurement can be instructive. Don't try to get any meaningful info doing it by hand though. ASTM D2240 explains the right way to do it, but the gear is not cheap, unless you score on eBay or where ever. BTW there is no way to actually measure the finished poured wheel durometer according to the standard but if you use the same method you will find a good basis for comparison. DO NOT try to measure on the grooves. You will get a low and inconsistent reading. Readings must be repeatable or you will still be on that fools errand.

3. Wheel sidewall thickness

This is because urethane changes shape under load. The thicker the tire, the more urethane there is to flex. Flexing is also known as distortion. (Remember urethane does NOT compress)

4. Wheel diameter

All else being equal, the bigger the wheel, the easier it rolls once it is rolling. Larger wheels are also harder to start up. Inertia is the player here. Note that all else being equal?? Typically bigger diameter wheels have more tire thickness due to manufacturing constraints.

5. Wheel width / Contact (footprint) width.

Wider tires have more urethane on the floor so these two seem to be same to me??

6. Treaded or not.

Slicks always grip better than grooved wheels on a smooth clean surface. There in lies the rub. Grooves can slow ya down because they flex more than a slick surface. Where grooves come in handy is when the floor is dusty. More grip. Ever see any indoor inline race wheels with grooves?? I have not.

7. Hub type, no hub, plastic hub or metal hub.

Not all hubs of the the same classification are comparable. I have it on good account the SG 1 piece plastic hubs come in 2 flavors, one made of much better material than the other. Neither are metal hubs.

8. Hub cap type (Atoms).

I don't waste my time there. The OG hub cap evolved from the ROCK R-Tec through Matter, Answer, and finally Atom. It took Atom a while to make the issue go away... What 8 to 10 years?? I don't remember exactly. BTW Neil Pipers AEND was pouring all of those.

9. Pigment or no pigment (nats...natural color)

The book agrees. Wheel color built into the urethane is an "impurity".

OH, this is why I moved your intro to the end. Although this falls into YMMV I have some questions / comments which I will insert as I go.

A while back. They had too much pigment in them. They were supposed to softer but turned out much harder than projected.. They rolled like mad but would not stick except on unused floor(back of the rink in the turns next to the wall).

I have some not quite VFH (Scott says 99) prototype Wickeds. Purple. Grip about the same as my Natural VFH?? Almost all my sk8ing is done on a clean wood floor that has not been coated in..... (IKD... forever??) No grip issues, and this is not just me. Here is where the suspension setting plays into the game.

They would slide forever. Using this as an example as SCOTTS are the absolute #1 wheel in the Quad Skate World!

Won't argue that. And I am amazed @ how many folks are afraid of the price. Yeah burn through a half dozen sets of Bones Turbos before the Scott's start to wear in.

Any pigment added to the mixture affects the grip. I ran another set borrowed from the same guy, they gripped and rolled awesomely!

Same sk8s, same action adjustment, same floor, same weather in the rink?? If you did the comparison any other time than one right after the other, way too many variables can mess up the perceived results.

So it is just what happened when the customer ordered his specifics, then got what he ordered. I feel that wheels that are dyed get pigment but it is more like "stained" or color on instead of being part of the mixture. I could never tell a difference in grip once my wheels were stained compared to the same wheels that were never stained. JMO.

I have never dyed a set of wheels to compare one or the other. I have a couple of sets I sk8ed up and they seem to perform ~ the same as their undyed brothers / sisters. Basically my results don't match up with yours. I have been rolling Scotts Enforcers since before the beginning. I still own some of the original tires and wheels. Don't sk8 'em they are scary looking. He has come a long way baby!!

I think this covers just about everything.. but there may be more that I haven't touched on.

I'd say you did a darn fine job spelling it out!! I would add one more thing. The weight of the rolling assembly, wheels and bearings. The more weight you have @ the end of the pendulum, the more work you need to put into making it move.

Basically, in how a wheel performs is not restricted to just hardness. Hardness plays a big role but it is not all there is to it.

When all of the factors are figured in durometer can be helpful or lead one off into the weeds.. Understanding that the sk8ing space, can override every other aspect is really important to making good decisions. The guy that got me into this years ago hated Cannibals. Why?? He got onto a floor that did not agree with the green ones but he blamed it all on the wheels. The wheels were fine, I used them on a lot of floors. He didn't like the OG Green Shamans either. YMMV

IMO that these properties being combined into a wheel produce footprint size(squish), roll characteristics, hub deformation and grip. All the things we want in a wheel.

Just what do we want in a wheel?? Grip when ya need them to, break away gently when ya want them to, and roll like mad all the time. I got several wheels that are darn close to meeting all of those.

One wheel won't do it all. So multiple wheel sets are needed for different floors and uses.

Still thinking inlines?? There is no suspension adjustment to help with the traction. (one of the reasons I am not a big Arius fan.) I sk8 with a fellow that has raced quads a long time. Yellow Lips everywhere according to him. Adjust the action on his Pro Lines 1/2 turn max according to him. My results playing that game match up. have not switched wheels in years. Just tweek the action.

A derby skater will want predictable slide and slip. Speed skaters want awesome roll with minimal slip. Sessions skaters(turning and slicing) mostly would want awesome grip with no slip.

ODD. All I do is session sk8. I want wheels that roll like stink, grip like mad but break away predictably.. As in all of the above.

Dance, figure and others will want something different or a combination of things above. Some want to just Slide.........>>>>....
Basically, I think the point being made here is don't get locked up in the "What duro are these wheels??" mode. Way more to consider..especially understanding how your sk8ing space behaves over time may be more important than anything else.
"The difference between good skates and great skates comes from knowing where to get the numbers."
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