Greetings and looking for some help. I have just moved from a country with very smooth roads (singapore) to one (Prague in the Czech Republic) where a good part of my daily ride is on cobblestones and across scores of tram tracks. Don't think of american brick or cobblestone roads. At times, these stones can have 2" deep and 1" wide gaps....and height differences of an inch or so.

I have a Giant TCR-C with Equipe wheels. In Singapore I used to run Michelin Pro 2's 700x23 but was getting a pinch flat every month or two (running them at max pressure of 8 bar) from road debris (rocks). I switched to Vredstein's 700x23 which can run 12 bar and fixed the pinch flat problem.

But for the cobblestone I was thinking I needed a wider and taller tire to better distribute the weight (I weigh 190) and cushion the impact with the stones.

So, I went to the LBS here (thankfully they spoke a bit of english) and got some fairly cheap Specialized All Condition Sport tires--700x28 for the front and 700x25 for the rear (the 28s are too wide for the rear). I am running them at 8-9 bar. But, the rear tire has a slight rub against the downtube. The gap between the tire and the tube is only the thickness of a couple of dollar bills. But the tire/rim has a slight high spot, and when that high spot comes around, I get a slight rub.

So was wondering a few things. First, any suggestion for a rear tire that might fit a little bit better? Second, does anyone have experience riding a lot of cobblestones on a road bike--can I ride the Vredstein's without flatting? And third, can the Mavic Equipe wheels take the pounding of cobblestones without being ruined?

Thanks much