I had a rear tire blow out on me this morning on my way from a meeting to work- was riding my wr250 with knobbies. Not my first time with a flat, but have never had one blow out before. I was riding along at 55 on pavement with everything feeling normal when all of a sudden I felt the rear end coming around- I was able to straighten it out and keep it upright fortunately, but as I am sitting there trying to keep it upright and straight I was wondering what would happen if I hit the brakes- my sense was that I would lose what control I had of the bike and that it would go down. I was at the top of a downhill when it happened so what I did was let off the gas and focused on keeping the bike upright while thinking "I'd really like to get off this ride NOW!" Eventually I got to the bottom of the hill and the bike finally slowed enough so I could pull in the clutch and get over to the side of the road and stop. My husband and I have already done a post mortem on this- just because the tires were fine when I left the house does not mean they were fine when I left the meeting. Also have discussed the pros and cons of rim locks. He came and fetched the bike with the truck and changed the tire- the tube had completely come out of the tire and was so shredded he was unable to tell what the cause of the blowout was. My question is- if I had braked would I have lost control of the bike and gone down or would it have merely transformed my 2 minutes of terror into twenty seconds of terror?