I did a quick spin around the Headlands last night after work only to be dealt a bad hand by the Karma gods. My rear tire cut open, spewing sealant all over the place. No way to fix that mess. I knew I had half a charge left on my light, and no way of getting home other than calling my wife to come pick me up. I knew she wouldn't be happy about it, or the fact that I was mountain biking by myself at night. So ends my night riding. No sense in making someone else worry about my safety.