So going to work today, and uphill at that, I was charged by two dogs. One pitbull the second a shepard. They came from the right side, shepard pulled in behind me, pitbull beside and snapped away at me. I stood on the pedals and hauled but they were able to keep up easily. I cut left across two lanes of traffic but they kept coming. I took a hard left onto the sidewalk but couldn't get straitened out fast enough and hit a large decorative rock, Landed ok with my hands up, the dogs took off guess I wasn't interesting anymore. My rear derailer is destroyed, and I fear my tires are VERY out of round now. I fortunately have a walmart bike and the replacement derailer is 15.99. I just hope that nothing else suffered any damage that will be expensive. I went to a sporting goods store and bought mace with CS tear gas, this WILL NOT happen again. If I had been a kid or a bit less lucky this could have gone much worse. Good news, not a scratch on me and the helmet didn't even get bumped. Bike gloves saved my hands so I'm completely unharmed. The denali is a rock though that was a HARD crash it took, and it still got me to work (although in only one gear) before it gave up the ghost.