Any number of causes there.
Reminds me of a trackday story, so I'll do a little bench racing here.
Back in the day (when I walked to school bare feet uphill both ways), I was on a GS500 doing a trackday in the B group. The turn was a fast banked sweeper leading onto the back straight. I was stuck behind a Super chicken who would squirt down the straight and park it in the turns, he would always swing way wide in this turn before turning in (ie, late apexing like it's a decreasing radius turn when in reality it's the opposite). I finally get a chance to tuck under the guy in the sweeper and proceed to use the prodigious 37hp to initiate the pass. Except he's squared off the turn so much he literally runs into me from the side, putting a nice fat dent in my pipe. To top it off he later came up to me and wanted me to claim fault on my insurance!
