I seriously would appreciate some well thought out input from any of you.
Yesterday, 4/28 my friend George was riding to my office on his new road bike so we could commute home together. I've been encouraging him for a long time to try bicycle commuting and this was his first week to try it. Unfortunately, on his way to my office he later related that one minute he was rolling along perfectly and the next moment the paramedics were trying to revive him.
He doesn't know what happened. He suffered a fractured skull, concession and numerous contusions all over his back. His helmet was destroyed. There were no witnesses, he was simply found lying on his back unconscious in the roadway. Today 4/29 he's OK, just very sore.
The cops and paramedics insisted that he had a blow out. I believe that's highly unlikely. When I examined his bike approximately 5 inches of the front tire bead was off of the rim on the right side. The tube was visible inside with a 5 inch slit running longitudinally. There did not appear to be any damage to the tire itself, no puncture.
The road he was traveling on is smooth and clean, I checked it.
My theory is that his tire lost pressure slowly until it got to the point where the tire bead popped out of the rim and jammed into his front brake resulting in a traumatic endo. He may not have noticed that the tire was getting low as he is a new rider.
When he arrived at my office earlier this week on Tuesday 4/26, his front tire was very low but we aired it up and he made it home without incident. He took the bike to the LBS and they checked everything out and wound up having to add about 25 pounds of air pressure again. He didn't tell them about the earlier incident so they probably thought he was just riding a little low.
The tire bead slides easily in and out of the rim using thumb pressure only; that's what leads me to believe it could have separated due to inadequate pressure during his ride.
We're trying to figure out what could have happened and would appreciate any input you may have.
Sounds like he had a blowout.
The tell-tale slit in the tire is typical.
It happened recently to a local rider and he swerved into the path of an oncoming truck.
Your frind sounds lucky.
Hope it doesn't discourage him from riding.
It's possible that he lost enough pressure for the tube to get "pinched" while he was riding. "Pinched" between the rim and tire bead. When they blew it back up the second time, it worked it's way out while he was riding, and blew out the bead. I saw it happen on April 17, when a guy replaced his tube without checking for a pinched tube, but it blew out before he rode it. It actually blew the sidewall off the wire bead on a Conti Gatorskin. Anytime a tire has lost pressure and is aired back up, it's a good idea to lower the pressure enough to be able to check the bead on both sides to ensure the tube isn't pinched.