you'd be surprised at how much grip rubber on carpet does have, but nowhere near what foams would give you.
i would say that for a stock racer, tyres are going to last anywhere up to 10wks. For modified touring, you're looking at 4-6wks.
Sorex are my brand of choice.
Sorex 20R gives best grip on the carpet we use (ozite).
Sorex 24R gives me good grip with longer tyre wear
Tamiya Type As give awesome wear, but not as much grip on carpet as I'd like. I'd stick to 540/Stock racing with these. Easily worth over 1000 laps (sorex for me are prob 500 laps).
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