Originally Posted by johnnytheboy

the white is salt buildup from his sweat. never ridden on a trainer, just raced outside about 300 miles from the nearest coast. being a pro race mechanic for many years has taught me that some people's sweat is just way more acrid than others. i've seen this several times, but this one was the most gnarly of all. the best part was he brought it in the day after the first road race of the season where riders routinely hit ~50mph on a lengthy decent. scary stuff.