Originally Posted by
unterhausen
I rode gravel for a year on 30mm tires and got 20 flats. YMMV, depending on the nature of your gravel. The issue around here is there are some giant embedded rocks and you will inevitably hit them at speed. With the 38mm I ride now, when I hit one of those rocks it only feels like my tires bottomed out. With the 30mm, it would have meant fixing a flat.
Unterhausen - I rode across PA a few weeks ago on some of your chunky mid-state stuff. Man there was a lot of loose gravel most everywhere in central PA. None of it sharp and no glass, but LOOSE and chunky.. 650b territory I say with 47mm if you can fit it! Even the pea gravel was polished and rolly on hard pack underneath to make things interesting and slippy. And with the lack if rain the dust clouds were thick enough to provide shade from the beating sun if you were not first in line!