Well, after starting this thread I succeeded in dillydallying around at home until the parade was almost over, so I ended up not seeing any of the bicyclists this year (there were also a fair number of ladies wearing only thongs and paint but sans bicyclettes, I'm told, but I missed them, too). So I can't say for sure (and don't recall from years past) what if anything the gentleman cyclists do to guard their balls. Whatever I might suggest would be pure speculation.
This evening, though, as the fair closed, I scored big. Next to the church's booth was an organic farm booth that had been giving away fruit and veggies all day, and as they prepared to close I asked if they wanted the cauliflower I was eyeing covetously, and the fellow said by all means take it and take all the rest of that stuff too. So I ended up with a cauliflower, two kiwi fruits (Chinese gooseberries), a bermuda onion, four yellow onions, a bunch of scallions, three cloves of garlic, a peach, a canteloupe, six new potatoes, a dozen small red potatoes, three oranges, some red chard, four plums, and a partridge in a pear tree (kidding; but it felt like it). All certified organic, and all except the rather wilted chard absolutely gorgeous. I actually prefer vegetables over naked gentlemen on bicycles almost any day.