Originally Posted By: supton
What tire size? I manage ok with 25mm tires on hardpack dirt roads. I get sad pretty quick on soft dirt roads, but I've taken my bike (albeit a triple) places it should never have gone. My wife has a bike with 23mm tires; I rode it in the driveway once and immediately realized, she wasn't kidding, the thing was scary in dirt. Perhaps geometry has some (lots?) of play in that too, as my road bike is more of a touring bike, slow(er) responding steering, longer wheelbase.
I'd have to look, they were not insanely thin like the tires one of the triathletes in my group used...I thought those looked like long earthworms stretched over his rims. I never switched down from the size that came with the bike, although I did change the tires at least once.
These roads generally get a good grading once a year and then are in decent shape for about two weeks after that...usually they are washboarded like crazy but with really soft shoulders. The busiest road is about 1.5 cars wide and most people drive right down the middle, so getting on the shoulder can be essential for bikers to stay alive. I definitely would not want to be clipped in riding up there...they are also steep enough in sections that my double ringed crew cursed me for taking them up the short paved section of the main road to my neighborhood (turns to dirt just past us).
So, there are a bunch of reasons I don't take my double ring road bike up there...I don't mind braving them on my triple ring, short-geared hybrid bike.