The roads arent chip seal thankfully. Just asphalt thats out in the country and well used.
We run the Gatorskins right at 120 PSI. I figured given our weight we needed to keep them at the max pressure. I could try dropping them back some and see if its any better. But yea, the tandem just beats us both down. Ride a century on the singles? No problem. Even as out of shape as I am right now, I wouldnt hesitate to go out and ride a century. 35 miles on the tandem and we're both ready to get off.
The issue with the tandem is we both feel like we're killing ourselves and going considerably slower. Its been that way since we've had this thing and one of the reasons we havent ridden it more than we have. Its just slow and not as much fun as the singles which kind of stinks because we do enjoy the time together on the tandem.