Schwinn DBX? First-hand report? Right here! Ride it almost every day.
It's a very good bike if you are not a road racer. The frame is about as light as you'd want for a utilitarian light touring bike or 'cross bike. (And, I carry the thing up and down stairs every day.)
It has decent components, mostly mid-line, which is what most people want in an everyday bike for commuting, light touring, and as a lightweight utility riding "steed". Are the components good enough, you still ask? Well, mountain bikers know that TruVativ makes good drivetrain components,and the compact double crankset (50-36) provides the right range for most people without going too low or too high. And, the Avid 7 road model (designed with shorter cable pull than the mountain version) mechanical disc brakes? Top of the line! And, the "extra" brake levers ("cross levers) are a lifesaver for someone with small hands (like me).
Don't like discs? The bosses are there for canti's/V's., too.
The surprises? I actually find the WTB saddle quite comfortable, and the open-design Wellgo combo pedals are not nearly as heavy as the older Shimano 324 "knockoffs", and also work surprisingly well. The carbon composite fork does soak up road shock decently well...and we do have rutty roads here. I changed the carbon composite seat post to an alloy one because I did find the big weakness of the bike, if you want to call it one: The disc brakes make it impossible to attach a normal cargo rack, and frame-mount racks that have been designed to fit around the disc brake caliper are not available here, so I needed to go to a seatpost rack!
As for the actual clearance, fork and stays? Plenty for just about any width tire you'd fit to a pavement bike. With fenders in almost any case! The stock tires--Vittorias--are a bit "tiny" for the rims (25's are barely large enough to fit!). They run OK, and they do resist those punctures! (The roads are paved with broken glass here, too!)
One more point: If you want to pull a trailer? Will do that, but a loaded trailer, such as a Burley cargo, is about what it can do--don't try to load it up like a Trek 520 or a Bruce Gordon touring bike. But...it won't fall apart when asked to do the job of trailer pulling...if the trailer is not too large.