Beautiful day...70 or so. Rode to work/summer camp (me to work, son to summer camp close to work). had emergency in middle of ride.....he forgot to bring brownies...lucky for us a supermarket was two blocks away. Dropped him off and raced for the meeting (I lead) that I was a bit late for. Noticed I was working harder and losing efficiency....figured it out at work...my seat slipped. It is amazing how much more work it is if your seat hight is too low. Life is good.