I solved my problem!
 

Caution- this is longer than it needs to be, but if this story saves one person from going through the struggles that I've been through, then it's worth it.

Problem:
In the past 1.5 months I have had an incredible amount of rear flats and it has been driving me insane. These were not just slow leaks, they have typically been major blowouts and I could never figure out what was going on. When I would change the tire, I would always check the outside and the inside of the tire for staples, glass, etc, but I could never find anything. They are older Rolf Vector wheels that I have trashed through commuting and even racing cyclocross on, and I thought that maybe I had a spoke loose that was poking through the eyelet and puncturing the tube because the blowout in the tube was so major. But upon inspection, all of the spokes were tight and in decent shape. One day, I was so fed up that I stopped off at the LBS and purchased a new tire in the middle of my commute. Oh, by the way, I commute on Continental Ultra Gator Skins (700x23c) and have always been very happy with them. But the flats coninued every so often even with the new tire.

Solution:
I walked back home after my flat at 5:30am one mile after leaving home. It was 32 degrees and I also didn't want to use my one one spare tube this early in my commute (especially with the luck I've been having). I get home, change my clothes and drive to work. After work, I get home and throw the bike on the workstand that my girlfriend bought me for christmas. I carefully take the tire apart and check it several times. I check the spoke tension again. No problems anywhere. I match up the whole it the tube to the spot on the tire and wheel and I cannot find anything that might be the culprit. So I throw it back together, put it back on the bike and then pump it up to 115 psi. Since I now have a stand to put my bike on, everything is at eye level and much easier to see. This is when I notice a small portion of the tube protruding out of a small tear in the sidewall. I immediately mark the tire and relieve some of the pressure. I then spin the wheel in the bike and notice that it is very slightly out of round in one spot. When the rim passes the brakepad in that one spot, the braking surface on the wheel dips down and the breakpad just barely nicks the sidewall of the tire. It just barely touches it and isn't even audible. So my diagnosis is that over time the pad nicks the sidewall enough times to create a whole large enough for the tube to protrude at 115 psi. Then BANG! At that point, I change the tire and since the very small tear is no longer under pressure, it is not visible. I put it all back together in such a way that the tire is in a slightly different position on the rim and it is just a matter of time before it wears a new rip in the sidewall. The wheel is just slightly out of round so that I never even noticed it. So I am going to take this wheel and bury it in a very deep hole where it will never be seen again and cannot give me anymore trouble. I only wish that I had gotten that bikestand as a Thanksgiving present. Could have prevented a lot of headaches.

nate

You have reminded me that I need to inspect and clean my bike soon. Or, should I say, clean and inspect?

Good catch. I also have some Rolf Vectors (great wheels, btw), so you reminded me of my own mystery flats a couple of years ago.

It was driving me crazy and after the 3d tube change in 75 miles, I happened to look at the rim tape. It had shifted just a few milimeters to leave a tiny gap over one of the spoke holes. At full pressure, the tube bubbled into the spoke hole and eventually popped.

I was able to fix it with a couple layers of athletic tape. That worked so well I just left it until it was time to buy new tires and I got new rim tape then.

<cheap SOB>couldn't you just move the brakepad a little so it doesn't rub the tire anymore?</cheap SOB>

Yet another argument against brakes.

You could have also taken the wheel in to get it trued, as well...

One night I grazed a small rock and put a tiny tear in a sidewall. That night I had the bike in the stand and fell asleep in my recliner in the same room..

At 3:00 am........................BOOM !

My kids even came down from upstairs to see who was shot.

I could do that, but these wheels are tired and ready for bed. They have been good wheels, but they originally came on a cyclocross bike that I bought used from a friend, and I've ridden them hard for 3 years. They are also the bottom of the line rolf's and the rims are in rough shape. The rims/spokes have been pretty maintenance free for the entire time. I've been told that it is difficult to service those wheels because the tension is so much higher than a standard spoked wheel. I've repacked the hubs a couple of times and the bearing races are showing signs of pitting. It is their time.

Ever have this happen? Most of my flats are rear tire...no mystery there. Front tire kicks up a nail that hits the rear tire perfectly and hisssss it's flat. I had two incidents though (same bike and same rear rim) where the nail not only punctured the tire but went clear through the Tuffy rim liner, the tube, and finally through the rim and out. The second time I had to walk to work and use a pair of vice-grips to pull the nail back out of the rim. That rim must be jinxed.

Fenders and a long mud flap on the front tire may help prevent that. You may want to do a search for recent mud flap posts on how to make one.

Actually I have fenders but I really want to make some sort of mud flap to reduce water spray on my shoes. The nail through the rim was just a fluke but dry shoes on a rainy day would be well worth it. I'll do the search...thanks much!

I have made mud flaps for all my bad weather bikes. I use an mtb tube. I cut it open to a flat piece then double it back on itself to be two layers thik. You really need to do this or it curls right up. I just use tire patch glue to hole the two pieces together. To make some of the longer ones stiff at the bottom I just run a piece of stiff wire across part way up and just crimp the ends over the other side and squeeze it with pliers. To keep from drilling the fenders and to provide an easy way to take the flap off I hold it on with two pieces of wire across the flap and about 1/2" piece crimped under the bottom of the fender, and squeeze this with the pliers. It's easy to take off if you need to replace or repair the fender. The longer the better, down to 1" off the ground is good, but then it must be something flexible so it won't hang up on solid objects, like rolling the bike down stairs. If the puddles are deep just slow down and you can keep your feet pretty clean.

Cool idea! And finally a use for all those perforated MTB tubes.

Did you want to be in manufacturing, or sales? ;) :)