I just wrote this up for canadianunicycling.com and decided to post it here as well.
I am going to go through how I stud a tire. There are many ways of studding a tire but this is what I found works best for me.
What you need
An extra innertube or other barrier.
Choosing the right tire is the biggest factor in whether you will be happy with your winter tire or not. Generally in winter you want a tire that is as wide as possible and has a relatively open tread. I would not stud an old worn out tire as the whole point of studding a tire for winter is to have the most grip possible. The tire that I am using in this tutorial is a new 26x3.0 Duro Wildlife Leopard.
The best screws to use are #8 self-tapping metal screws at a length that sticks out 1mm to 3mm. On most tires I have done this means a 3/8” long screw but the duro has slightly deeper lugs and I needed to use 1/2” screws. Do not use wood screws as they are made of softer steel and have skinnier points resulting in them wearing faster.
The first thing that I did was plan out my stud pattern. I decided to do a pattern that would utilize three different lugs varying from next to the center to the second closest to the edge. Generally I do not put studs in the very center or the very edge as the center will get worn away quickly adding more drag, and the far edges are rarely used. You do not want a screw in every lug as the plain rubber lugs will give better grip on surfaces like rock and clean pavement. I used a grease pencil to mark the lugs that I wanted studs in to help me remember where to make the holes for the screws.
Making the pilot holes
In a few studding tutorials that I have read people suggest using a drill with a 2mm bit to make the pilot holes, this is probably the fastest and easiest way to do it but I think that you should try to keep as much rubber as you can so that it effectively presses against the side of the screw preventing it from popping out.
I used a fork with one tine bent out and sharpened to a point. I would stab then give the fork a spin to make sure that I would be able to see the hole later from the other side. This took me about 15 minutes and the fork got quite warm after a while
Inserting the screws
Once you have all your pilot holes in place turn the tire inside out being careful not to kink the bead of your tire. Now all you have to do is drive the screws into the holes you just made. If the screw does not follow the hole you made just back it out and try again with the screw at a different angle.
Finishing the job.
Some people snip off the heads of the screws with a bolt cutter to save some weight and reduce the risk of pinch flats. I don’t like this practice because it makes it much harder to remove the studs if they need to be replaced. If you do cut off the heads make sure you don’t have any sharp ends pointing inwards.
You want to cover the heads of the screws with something to protect your innertube. The best option is an old innertube split down the middle. Another option is to apply several layers of duct tape to the inside of your tire. I attempted to rubber cement the old innertube to the tire this time but it did not help keep everything in place as well as I hoped during installation so I do not suggest doing it.
Install your tire and go ride