How Lip Shape and Profile Effects Wheels
JW: Wheels have loads of variables that impact their performance, lip profile being one of the major ones. The shaping of lips, whether they are sharp and come to a 90* angle, or rounded off will dictate how the wheel interacts with the pavement. To put it simply, a sharp lip will flex and dig into the pavement when turning, providing more grip. Rounded lips often will not flex as much, and generally offer less traction and want to go sideways easier with less force required.
Along the same lines, rounded lips typically have denser profiles, giving the urethane less possibility to flex and more potential to slide. That's not to say you won't encounter wheels like Cadillac Sugar Mama's or Free Willies, both featuring thinner round lips with notably more flex for a round lipped wheel. Remember Hoots or Little Hoots would fit in the same category based on shape, but with how much their specific urethane rebounds the lips have minimal flex.
The Boss Hawg has what's called a hubset profile, this means that the wheel has virtually no lips at all which constitutes a wheel that has little to no deformation. This means that there is no lip for the pavement to grab on to, therefore a very smooth and effortless slide.
When it comes to square lips, the thickness of the lips will determine how much they grip. Having a square lipped wheel with relatively thinner lips like the 70mm Biggie Hawgs, the lips are more likely to deform simpl because there isn't as much urethane supporting the lip overhang. This means you will have more grip because when railing around a sharp corner, the lips will flex and deform to the pavement providing more contact to the road therefor more grip.
When it comes to a thicker lipped wheel like the Divine Crucibles, since the lips have more urethane supporting them, they are much less likely to flex and deform while taking a sharp turn. This means that the wheel will maintain its shape and there will be less contact to the road, this allows for smoother slides as the lips aren't digging into the pavement as hard.
As you can see, the Crucibles have a 10mm lip, while the Biggie Hawgs have a 6mm lip meaning the Biggies will deform much easier than the Crucibles.
When it comes to the riding experience, you will want to ride a wheel that has a thinner lip at a hill like Maryhill which has a lot of turns that don't require sliding. For a hill that requires sliding you will want a wheel with a thicker lip to make the kickout of the slide easier with less hookup.
A wheel profile that is neither square lip or round lip is a beveled lip which is when a square lipped wheel is chopped at about a 45* angle. A beveled lip on a wheel like the Cloud Ride Slides and Mini Slides will provide a similar feel to a square lip except it has that little extra bit hanging off the side to support the urethane better. This allows for a much smoother slide than a square lip, but not as easy of a kick out compared to a round lip.