Originally Posted by
freediver
Seeing as this is Wisconsin, and not Colorado, full squishy seems overkill- especially for touring. If I lived someplace with actual mountains I might think different.
I'm also not worried about the rail-to-trail routes as they are smooth enough to ride on with my road tandem fully loaded with kids in tow. My cross bike with 38's also worked great. Pretty much everything I've tried works well on those. Fenders helped whe the ground was wet, but things never got so soft, or rutted, that I ever needed much more than that.
"Mountain bike" is just a name. It doesn't mean that the bike can only be ridden in mountains or only on steep trails. When you say
It was an ATV trail (Cheese country trail) that was so crappy I only made it 11 miles in two hours after I crashed a couple times and tweaked my knee
that just shouts "mountain bike!" Maybe not a dual suspension but at least a bike with a front suspension. Another advantage of a mountain bike for touring is that it opens up parts of the world that you wouldn't necessarily want to do on a bike that would cost you 2 hours, 2 crashes and a tweaked knee. Additionally, suspension front and rear is going to provide you with more suspension then 4" of uncontrolled bouncy rubber is going to provide at the same or less weight. 4" of tire may be nice on sand or snow but it's just a basketball when you are on rocks.
You are correct that a cross bike...or a touring bike which is better for touring than a cross...will handle a railtrail. I've done the length of the Katy once, and most of it another time, on a loaded touring bike and had no issues. But I've done railbeds here in Colorado several times that I wouldn't want to even attempt on a loaded touring bike. For those I pull out the mountain bike. As an added bonus, I can explore connecting roads and trails that I couldn't even attempt on my touring bike.