[paradocs98]

You can probably get away with doing it every other season if you're doing 10 trackdays per season, but I feel more comfortable putting on a fresh set every spring before the season starts. I feel this way because 1) they see a lot of action with two wheel changes per track event, 2) it's not uncommon for them to fail or break when they're tired/stressed, 3) my 75mm TMS studs are on the car year-round, and are therefore exposed to road salt/sand/grime in the wintertime.