I took the winter commuter out for some errand running this afternoon and pondered some possibilities while not particularly enjoying the ride. Perhaps one problem is that my current road bike of choice is a sub-20lb titanium rig with 38mm tires. Perhaps I just don't like the geometry/ride qualities of MTBs refashioned as upright (or flat) bar commuters. I've tried several over the years, some reasonably decent ones, including a Ritchey Ascent that I even put some high-zoot Compass tires on, but it didn't really do it for me. I have road bikes in various configurations I could repurpose. I have a couple of sets of Schwalbe Marathon Winter tires in 700 x 35mm that do reasonably well in ice/snow. I also have my gugicafizioned '71 Raleigh Int'l, currently with 650B x 42 Soma Cazadera tires, which work quite well in snow--though winter commuting in the Boston area is really hard on a bike, particularly given the constant brine of road salt and slush, and I don't want to abuse that bike more than I already do. I have a fairly rusty Lemond Tourmalet on the indoor trainer that could likely take 650b x 38mm wheels, maybe even 42mm. Hmm.