here's where i'm at now. use the same frame i have now, schwinn le tour. front drum, rear drum/3 speed igh. should leave more than enough room for big tires + bigger fenders. a front disc is not out of the question.
well, all things aside, studded tyres first and foremost, otherwise the only braking you'll be doing is on your side, horizontal road rash style. ok, you can get by without them (i did for five years in iowa city), but life is seriously more fun and safe with them. i like my disc brakes plenty in the snow and rain and never plan to use anything else, but you can get by fine without discs.
a few things have changed, and i'll be able to get a surly karate monkey as an employee discount this summer, so i'll probably do that. i think i'll use it as just a mtb over the summer. i want to do something with an internal hub as a winter commuter. i'll only know once i finally decide what to do. the cost for me would be ~$500.
Winters Past: Temperatures can swing about 50 degrees in a day here in the winter. 65% of my riding is on dry/non slippery ground. For two winters I've been riding an 80's steel touring frame with a shimano nexus8 speed internal gear hub, and v-brakes(custom braze job). My favorite winter commuting tire is the forte (performance brand) SpeedTrac/K tires (700X35). The little soft nubs on the SpeedTrac tires compress and grip wet stuff surprisingly well, and are closely spaced to roll fairly well on dry pavement.
Daily Winter Commuting and What Didn't Work for me:
-Studded tires-Personally I cannot tolerate riding studded tires on dry pavement-yack! Great for the dedicated-storm's coming bike, but ultimately expensive for those rare and less than predictable occasions. DIY sheet metal screw studs are less expensive, but even slower and more prone to puncture flats in February. What's wrong with removable chains?
-bolt on full fenders-clog-game over.
-mittens with permanently stitched in liners-don't dry fast enough-I've had success with removable wool liners and wind-blocking over mitts with tough palms.
-cleated shoes-are usually designed to eliminate heat-don't use nice stuff in the winter, and be prepared to walk in slop.
-externally geared (cassette-derailleur) bikes, quickly turn into single speeds or slip-in-any-gear-bicycles when ice forms over the unused cogs. They are excessively high maintenance/and or inefficient in winter gnar.
-Fixed gear-great for short inner-city jaunts, just not for me.
Winters Future:-This year I plan on making a set of tire chains, to carry in the pannier. My chains will be designed for fast on/off for use in surprise storms.
-Cold Fingers-I've been riding drop bars for the sole purpose of mitted hand operability (mittens are far warmer than gloves). My body doesn't like the reach of drop bars and I want to try handlebar pogies on my flat bars this winter.
-Cold Toes-I've been meaning to make some easily removable wind/water blockers that attach over my pedal cages. The iditabikers turned me on to using power grips for winter boot clearance and wider, less constrictive straps than the pedal cages(better blood circ) This still doesn't address the problem of dressing for 50 degree daily temp swings.
-rear drum/roller brake- My nexus8 hub has an attachment point for a hub brake, maybe I should use it and simplify tire chain use?
-front disc brake- my front hub has a disc mount, maybe I should get a disc front fork? This may not happen, as it will be expensive and not really necessary with a reliable hub brake in the rear.
-I've pondered chaining up my 29er's rear tire and strapping a short ski to the front tire. Anybody tried this? How to keep ski tip up? Lock the front disc brake?
-What about Installing wide (large marge) rims on the 3spd,igh,coaster brake beach cruiser. Gear it down and chain up the slicks for the sloppy/deep days. (compareable in cost to studs, but longer lasting and probably more fun the rest of the year)
-installing an expensive ktrak (rear track and front ski) snow bike kit onto a cheap wall-mart dual suspension bike as a designated storm bike. How do they deal with keeping ice off their cassette's? bottle of de-icer handy?
-calling in sick until the thermometer surpasses the 15F mark.