I've seen several post, where riders would like to know more about taking a perfectly good summer vehicle and prepping it for use on a substance normally only used to chill the beer.
I don't compete and can't comment on what's legal in this area or any other. We are just a bunch of buddies who through pointy things in our tires and rub handlebars. Just wanted to share what I've learned but I'm sure there are lots of guys here with more knowlegde than me on this ( and most things).
In the early days we would just screw a sheet metal screw in each knob and go. Its better than nothing and will work on the little bikes but most just spit them out which is a real bummer for the guy behind (don't be him).
Our current tires utilize "new" rubber, with two or three street bike tires inside for a liner. Street bike tires have the side wall cut off and are bolted/screwed to our new knoby. The knoby will have its knobs tapered down on one side if you only turn one way but we prefer to go both ways( that didn't sound good). Large two and a half inch wood screws are screwed in from the side to prevent the outer knob from "wiggling" and keep it as far from the chain as posssible. Then add 800-1200 1 1/2" studs angled ahead to bit into the ice. Then try to mount a tire you can hardly lift ( yes, they are very heavy) onto your rims. You will curse, throw things and buy at least two new tubes trying to get these mounted. Did I mention the skin you're going to lose as you slip and find out how good the new stud pattern bits? Most people buy spare rims after trying this just once, I'm slow and did it twice.
Throw in a little Slime (green stopleak for tires) to make sure that the tube doesn't have to come back out. Usually run a smaller tube cause there ain't much room in there. Baby powder (made from ground up babies) inside the tire cuts down on pinches and holes. Use lots of air pressure as you don't want any flex, drive them studs straight into the ice and keep studs away from chain, hell I'd run a solid rubber tire if I could get it mounted.
Other tips:
Header wrap on your pipe keeps the ice/snow spray from cooling off ur pipe and messing up jetting
Spray "shinnie" pipe with WD40 every outing to stop rust
Loosen lever perches, hard ice = new levers
Lots of padding, ice hard, aim for snow bank
Jetting, roughly, cooler needs more fuel. Manuals usually recommend turn AS out a 1/4 and up one on the clip, We've seen this right up to increasing one pilot size and 10 on the mains, you results may vary
Use lots of good oil and be preparred to kick lots cause these thing don't always like to start in the cold.
Wear goggles, if not, eyes water, can't see, tears freeze to head to helmet, buddies laugh
Don't sneeze in a full face helmet and a snow machine makes a good pull starter, not to many hills to bum start on a lake
So how does this work, ______ AWESOME. Imagine turning your half liter dirt slinger into an R1 with racing slicks on a perfectly smooth road course. Did I mention that every snow bank can be a beverage cooler. Scraping the pegs is doable (with you still on the bike I might add) and 1st,2nd,3rd,4th and 5th gear wheelies happen every lap.
Ok, I will shutup now but must add the standard disclaimer. I'm not a professional, not an expert, dismounted without a helmet, your results may vary, and yes this to can cause four hour ________ just like those blue little pills.
Working on adding the pictures....