I recently restored a 77' Zebrakenko Wind and purchased panasonic panaracer 27 X 1 1/4 tires for it. I am using it for my daily commuter.

The tires say 95 psi max on the sidewalls. I purchased an aergun x-1000 floor pump over the summer and used it for several months without incident with my touring bike running 700x28s. It has a pressure guage on it. I pumped the tires to 95 psi on the Zebra. All was going well until one night when I got home and had been off the bike for an hour or so. BANG, the rear tube ruptures - big gash on it. Hmm, so I thought, well, maybe that was due to using the old tube that came with the bike when I purchased it off of CL.

I then purchased several Continental Conti tubes - [Tour 28 (700C) ALL] - Schrader valves . The box says it is for 27 X 1 1/4 among several other sizes. I replaced the rear tube with one of the Continentals and left the original tube in the front tire. Weeks go by and then the other night, again AFTER I had arrived home, BANG - the front tube goes. A hole right on the valve itself - very strange. I replaced the front tube with another Continental.

At this point I lower the pressure on both tires to 90 PSI. Then tonight on the way home the rear tube goes again, one of the new Continentals, and again, a blowout.

I am thinking maybe the bead is not strong enough on these tires, but not sure. I had no issues with blowouts on the touring bike and using the aergun.

I think I will go to 80 PSI next.

Anyone have experience with the Panaracer tires or have any advice? Thanks.