Tire Studding Considerations…
Tires provide traction/friction because at a microscopic level their surface deforms slightly to interlock with irregularities in a road’s surface. Over-simplistically, in cold weather tire rubber gets harder so there's less interlocking going on, which means less traction/friction. "All-season" auto tires typically are made from slightly softer rubber for this reason.
When a stud is added to a tire for winter street riding it needs to be short enough to allow the weight of the vehicle to press as much of the tire's rubber surface surrounding each stud against the road. If the stud is too long this will not happen and one ends up riding on the tips of the studs only -- and this is very bad. There is almost no traction between the carbide tips of the studs and the road surface.
As a tire studded with a short studs rolls, the weight of the vehicle against the road forces the stud upward and into the tire, so most of the tire's tread rubber remains in contact with the road. But because ice is much softer than the road surface, whenever this is encountered the stud is pressed with enough force into the ice surface to chip out a little divot, providing some traction.
Obviously there is an optimum trade-off between how tall a stud should be above the tire’s tread, and how soft the tire’s rubber should be to maximize traction on both surfaces. Most winter tire studs intended for use on paved surfaces seem to protrude about ?" (or a little less) above the tire surface. The scooter studs (#4719 and #4720) are about this high, and are what we recommend…but I've actually never built a tire with these studs.
I have made, purchased and ridden on several sets of studded tires, but they've all been for off-road ice and snow riding so the studs have been longer. I've used these studded tires on pavement for a few miles but only riding at slow speeds and very, very cautiously. It's a very uncomfortable feeling, even riding a light weight bike.
The studs that are most suitable for street use are the #4719 and #4720 and in some situations the slightly taller #4706. If I were building a set of tires for winter street riding, I might experiment with mixing these types. Maybe one row of the slightly longer #4706's down the center of the tire, spaced about an inch or two apart surrounded by the shorter studs on either side and in between? The studding arrangement would depend on the tire's tread pattern. And regardless of pattern and stud types I’d ride with caution until learning the gripping characteristics of my newly studded tires.