... As we came down to 20 laps to go I had a bit of a problem... I had to urinate - and bad. In a road race I would drift off the back and have a teammate push me as I tinkled. Peeing off the bike is fairly easy; you just need to lean to one side of the bike and stretch down your bibs. You need to pick a long straight downhill section and one-hand steer your bike. Keeping track of wind direction, feathering the brake, and reducing post-pee-dribble all come with experience. There are a few more curveballs, however, when relieving yourself in a balls-out 8-corner criterium. The first is that you are always going 30mph or faster, the second is that there are spectators around the entire course, and the third is that you have to turn every 15 seconds. Like McGyver in the old TV show, I came up with a plan using the simple objects around me. The absolute worst thing that could happen is that I would end up with **** all over myself. I figured that was better than holding it for another hour. So here goes: I orchestrated my covert pee plan to happen as soon as the pace let up a hair. First, I prepared a water bottle. After I emptied the bottle, I pulled the top off. I put the bottle back in my front cage for easy access. Step two: I pulled my jersey up half way to expose my bib shorts (It would have been cake if I had regular shorts). I then practiced slipping the bottle in my shorts with my right leg at the bottom of the pedal stroke. I figured I had about 20 seconds of pee time if I could coast down the hill. Remember folks, if I pedaled while the bottle was in my shorts, I would have dumped a bottle of pee down the front of my crotch.
With 17 laps to go I took the topless bottle from my cage and stuffed it down my shorts on the inside of my right thigh. The pace stayed high so I rode like this for two laps. I pray no photographers took any pictures during these two laps or I will have girls calling the house non-stop. It must have looked really, really weird to the spectators as well. The race finally eased up a bit on a descent and I immediately got out of my seat, lined everything up, and started peeing with all the force I could muster. I managed to get around the downhill turn maintaining the stream without pedaling my bike. As I was just starting to lose contact with the field, I felt something warm and wet hit my skin and I knew I had overfilled the bottle and it was time to shut it down. I pulled out a full bottle of warm urine, dumped it out on the road, and jettisoned the bottle far into a bush. Luckily I was able to find the bottle after the race and make sure that a fan didn't use it to house his next cold beer.
I pulled the whole thing off without a hitch and the fans had no idea what happened. The whole adventure took my mind off the race for about five laps and before I knew it there were only 10 laps to go.
Source:
http://visionquestcoaching.com/2003-DownersChamp.asp