After searching for a creaking noise on my bike during pedaling, I finally found the chain ring nuts loose. (dah) anyway I was able to tighten 3 of them but the other two just spun. So I went up to my Favorite Bicycle shop and bought the park tool wrench for the chain ring nuts. Sure is nice to have the proper tools. My Bike specific tool collection is starting to look pretty good. I am a tool junkie though.