If there is one thing my fellow mechanics and I all agree on, its the fact that we hate to work on unsanitary bicycles. By unsanitary, I don't necessarily mean dirty like dirt and mud, its something we like to call "MAN GOO".
Man goo is a mixture of sweat, sports drink, energy gels, and sometimes urine. Man goo seems to occur more often on triathletes bikes. I think maybe this happens because the bike portion of their events seems to be the best time to eat, drink, and use the restroom.
Another unsanitary issue is the heavy sweater. Sweat alone can cause all kinds of damage to bicycles if not wiped down after riding. In all the years I've been working on bicycles, there have been some memorable gross bikes.
A couple of months ago, a customer brought in a bike to have the handlebars replaced. It seemed kind of weird because the bike did not look like it had been crashed. As I started to unwrap the bars, I was horrified to find this:
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The point of the story is a little windex after a messy ride can go a long way into keeping your bike safe and working well.
If you are a heavy sweater or ride your bike indoors a lot, its a good idea to change your handlebar tape at least once or twice a year. A clean bike = a happy bike and mechanic!