I have a Caad9 that I bought new in 2010. I have had an issue with chronic flat back tire ever since I got the bike. I was ( and am ) a newbie rider so I did some foolish things at first like not pumping up the tires before every ride. I have ridden 1250 miles each year for two years. I finally got frustrated at the end of last summer and put a teflon tire on the back tire and had my LBS check the rim out. It was retaped and a nick in the rim was smoothed out that I had gotten the first year riding. I got about 400 miles in between January and March and rode my trainer a lot. Never got a flat. Problem solved I hoped.

Last week I attempted a metric century and my back tire went flat at mile 56. Then this week I got another flat back tire. I gave in and bought a new wheelset thinking my back rim must have cancer. I put Mavic Aksiums on the bike and though a budget wheelset they blow the stock tires away. I took the bike on its maiden voyage and rode 25 miles and averaged 18.1 mph. Thats good for me.

Go to get on the bike today and low and behold the back tire is flat. One ride, new wheelset, same problem. I found the shard and removed it but I am still livid that I got a flat after one ride with the bike hanging in the garage. I guess I should just be happy that the flat went full bore after my ride was over.

What else can I do ? Change bike routes ? Walk the bike over the set of RR tracks on my route? Give up biking and run instead ?