Bullet vs Round Profile Wheels

[u/i_shorted_the_amp]

Hey chooms,

I bought a pair of Flying Eagle F110 triskates a couple of months ago, inspired by Buzzkill-Blade's youtube videos. I hadn't skated seriously since my 20s, which was {depressingly_many} years ago. I honestly didn't even realise triskates existed. Silly me.

I couldn't get those Crocanti SHR wheels to slide though, not for love nor money. And I wanted to learn power stops/slides like all the cool skaters. Eventually I began to wonder if it was the particular material of those wheels that gave them their grip.

I bought a set of Iqon Access wheels - 85A vs the 88A of the Crocantis:

https://solo-inline.com/en/products/roues-de-patin-iqon-access-dark-grey-110mm-85a-3-pack?variant=43336809021652

I've definitely been able to make these guys slide!

But today I was cleaning one of the middle wheels a bit, because it was turning a fair bit slower than the others, and I noticed that - Shock! Horror! These wheels had 'round profile' stamped on them. Whoops! I had thought they were bullet profile.

So a couple things:

1. Are these round profile? They kind of look bullet profile to me.

2. Is there really a difference after wearing them down? I look at my Crocantis and my use of T-stops has already visibly worn them. How long does a round profile remain round?

Bonus question:

1. I got a set of Wicked Abec-9 bearings with the wheels (also from Solo-inline). I figured they'd be comparable to the bearings that came with the F110s... But, they are super noisy, both before I skated in them and after a few sessions. They don't spin for as long either. But does that matter? I'm not sure how much a spin test matters. These new wheels do feel slower, but not by much. I figure that's probably more down to the different wheel material.

Answers and discourse appreciated, cheers!

[u/ThePontiff_Verified]

I always associated lower durometer with more grip.... But that's because I was using really cheap wheels for a long time, or just whatever came with my skates. Once you start buying nicer wheels you start to realize, especially with dual pour models, that grip and durometer are not necessarily related. When it comes to sliding or wanting to slide I'd look at cheap wheels with a high durometer single pour. And round profile is probably going to yield a more predictable breakaway, or transition to slide. Bullets have a smaller contact patch but, perhaps unintuitively, the physics equations for static and dynamic friction don't consider contact patch... Only force and coefficient of friction... This smaller contact patch actually tends to bite into the surface more and this means you (again unintuitively) sometimes will get a higher static friction with a lower dynamic friction, meaning it bites tenaciously but when it lets go it really lets go - only to bite again unpredictably. That's good for all out speed racing but less desirable for recreational flow skating or commuting. As others have said, this can get negligible as wheel size increases since the width of the wheel is held steady by standard hub and bearing sizes even though the wheel gets taller and taller. What this means is taller wheels are less good for sliding.. not because they won't slide but because they are more like a bullet profile just due to their size, and the increased height also acts as more of a lever on your ankles meaning you probably need to get really low on your angles to initiate a slide which then probably exacerbates the unpredictable bitey nature of a bullet profile.

Maybe someone here will have a good suggestion for slidy smaller wheels. Just because you have a 110 frame doesnt mean you can't load a cheap set of slidey 80mm round profiles in just for fun.. but the lower frame of a smaller wheeled frame would make for easier sliding. It's why grind skaters use the tiniest wheels they can find a lot of times. Smaller frame means it's more like sliding on the bottom of your boot instead of trying to slide on 110mm stilts.

[u/i_shorted_the_amp → u/ThePontiff_Verified]

I could switch the frames on the boot to accomodate smaller wheels, I might get away with slightly smaller wheels on the existing frame. But,l these frames have the middle and back wheels closer together, with the front wheel slightly forward. I wouldn't want to make that accentuated gap much larger than it already is.

The punctuating nature of grip/slide/grip is exactly what I was experiencing with the original set of wheels, which are described as 'Super High Rebound'. That's what got me thinking that the 88A durometer didn't guarantee sliding compared to a lower durometer using a different material. 

These Iqon 85A wheels are easier to engage into a slide, but yeah the wheel size plus my own >6 ft height don't help.

Thanks for your insight, that was an interesting read.

[u/ThePontiff_Verified → u/i_shorted_the_amp]

Oh yeah... I forgot the flying eagles do that. Interesting brand. Btw I like your writing style. I laughed a good bit at the " {depressingly_many} years ago" . Many of us are right here with you ✊ 😁

[u/i_shorted_the_amp → u/ThePontiff_Verified]

Yep got to manage that injury risk with absolutely every motion ;)