On an S40, but the concern is the same. I went down once with a front flat on my QX100, but that was early on in the initial learning curve. I've had several flats, front and rear, on the S40 and haven't gone down. Jason is absolutely right.
I run decent flat resistent tires (lots of brands to choose from, just go with personal preference) and tubes pre-injected with Flat Attack sealant. I carry a regular spare tube in the event of catastrophic failure, but the sealant generally takes care of things. Things like wire staples can be problematic if they get embedded, don't seal completely because the the wire continues to shift & the wheel ends up with the injury facing up. If I can find them, pulling out small irritants, spinning the wheel until the hissing stops & then adding more air as needed is all that's needed. I like the sealant infused tubes because I find them easier to install. Down side is that it is very difficult to patch a puncture the sealant can't close. Not that big a down side, though, since most of the time the tubes last as long as the tires or longer (though to be safe I almost always go ahead and put in a new tube when I put on a new tire).
