Originally Posted by hockeyteeth
Sometimes the cranks loosen on the spindle after you initially tighten them and ride for a bit. I've heard that this is normal and also that it isn't... If I were you I would just tighten the hell out of them again and watch for loosening.
+1. for about a week i carried a crank wrench with me to tighten the bolts after rides. longer than i needed to, but it gave me peace of mind to tighten the things down.