Tandem Tire and Frame Size Questions
I've been doing a bit of research but had a question about tandem tires.
I recently purchased an older Gitane road tandem. It is in nice shape, and rides fine. It has two old tires on the bike. The front is a 700 x 28c Schwinn record, showing cracking along the tire surface. The rear is a massive 35c specialized, with a max inflation pressure of 75psi, also showing cracks. The tires feel supple to my hands, but I'm guessing its time to get some new ones, right? My friend and I will be riding from Rochester to Ithaca, NY (95 miles) next week. If we put on new tires, should we carry ones of these as a spare tire with us?
The fellow riding as the stoker has a set of Michelin tires he just bought from Nashbar on special. They are 25c, and I don't know the model, but should know by the end of the day, and can add to this thread later. While I've read from other posts here that 25c tires can be OK, are their any things I should be wary about in using 25c tires? We are a combined weight of just over 300 pounds, and will be carrying 1 bag with a lock, some shirts, tubes and minimal tools. One note is that the 40-spoke Mavic rims are relatively wide, compared to my newer 700c road rims. Should using 25c tires be alright? Should they fit?
The second question is regarding size. I typically ride a 57-58cm frame. The bike is a 23" in the front and 21" in the back. The stoker fits the rear just fine, but with the very short seatpost that came with the bike, I'm finding I'm a bit short on leg extension. Is it OK to have my seatpost raised relatively high (7 or 8 inches above the top tube) or will this have bad effects on geometry and handling?
Thanks for the help - I've been riding bikes for quite some time, but I'm a newbie to tandem riding. It's been great so far.