Took a high speed tumble on Wood School Road at between mile 17 and 18 just past W. Sisson Rd when I neglected to properly secure my drink tube after stopping to fix a thrown chain. The tube started catching slightly in my rear wheel and I went down at pretty high speed. Just minor scratches on the bike but hefty road rash on my right butt. Shredded my riding shorts and my underArmor bottoms (cold start at 46F). Also got a scrape at the base of my right hand and a badly bruised right thumb. Bike seemed OK and I was still functioning so I continued. But then as I was starting my night loops my RD shifter bar end went loose. Tried to fix it but couldn't get the cable end ferrule to align back into the compression nut recess so I called it done and turned in my rider card for 163.1. I think I could have hit in the 260s without the mechanical.