Castelli claims that the jerseys they make for Saunier Duval (for hot weather) weigh 90 grams, or half of what normal jerseys weigh. More importantly, they claim that when they're soaked (with sweat or water) they weigh 140 grams while normal jerseys weigh 400 grams, which will save you a full minute in about 5 hours of riding on mountain stage. For amateur riders a minute means nothing but for a pro cyclist in a 3 week race, a minute every mountain stage means the difference between 6th place and first.

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