Ever see pics of the old TdF guys riding with spare tubs looped around their shoulders and behind their backs? Just the hassle of carrying an entire spare tire makes my choice easy...I've never ridden tubs, but even if the ride is 20% better than with clinchers I don't think it makes up for the 300% increase in hassle factor - certainly not for everyday urban riding. Same deal with the Tufo semi tubs...although Tufo makes a Slime-like sealant to put in them, you'd still need to carry a spare tire just in case. Yikes.
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Rock Lobster