I've been exclusively bike commuting 25 miles RT now for about 3 1/2 months. The road bike with 23c tires just doesn't hold up to the glass, screws, rocks, chugholes, etc. I end up blowing a tire every other day. And the Mountain bike doesn't have the gears to cruise above 20 without feeling like I'm spinning my legs off. The simple answer seems to be a cyclocross. Road geometry, road gears, and 700x40c tires just begs to be a commuter. Anyone have any experience with these odd beasts?

There's been a lot of discussion here about using 'cross bikes as commuters, and even as tourers. They can indeed be extremely versatile, and excellent commuters. Not all 'cross bikes have braze-ons and eyelets for fenders and racks, but many do.

The Surly Crosscheck and Jamis Nova are among the less expensive models that get mentioned a lot for this application. My Airborne is a frame that's designed as a 'cross frame, but depending on your choice of wheels and gearing it (like many 'cross bikes) could just as easily be a commuter, a road bike, a light tourer... what the British call an "all-rounder."

Here in Philadelphia I see a lot of 'cross bikes being used by commuters and also by couriers.

RichC

I have a LeMond Poprad. It's a cross bike that I have basically turned into a road bike and use for commuting from time to time. Unfortunately, no braze-on's for a rack. It tried the seatpost rack, but it makes the bike too unwieldy, especially on hills. So I just went with a back pack or messenger bag. I use 700x28c or 700x26c tires. Specifically the Specialized Armadillo tires that are very very flat resistant. It does have the braze-ons for fenders but I don't use them since I don't like to commute in the rain. I do ride in the rain from time to time. I actually gave up commuting because the ride was too short and the hassle with getting my stuff to work and showering half a mile away and then coming back to work was too much. Now I just do a 1 to 2 hour ride before or after work, plus my long weekend rides (4 to 5 hrs each day).

If you can find a cyclocross with all the braze-ons I would suggest it over a road bike. It's also lighter than a mountain bike. And the frames are usually tougher so if you need to ride on gravel or dirt trails for a short period they handle that pretty well too. About the only downside to mine is that I don't think the cantilever brakes are very powerful. Plus, most cross bikes come with a not so great drive train. I bought a model that was one year old new, and they gave me a $400 break on it, so I had them tear off the entire drive train and put Shimano 105 on. In the end, I got it for the price of a new bike, but I had a much much better drive train.

Also, check out the wheels they have. If they are tough wheels you'll be breaking spokes. That that would be the other upgrade I would consider right off the bat. I had two wheels hand built (Velocity rims, 36 spokes, 3 cross pattern, with ultegra hubs) for under $300. They have lasted me well over 3000 miles and are still going. And I'm a big guy... started last year at 294, and I'm down to 265 now... and hoping to get to 199.

I think the other nice thing about a cross bike is that it has a little bit more upright geometry, which was key for me when I first started. I need that more upright ride.

So bascially: good commuter bikes, but you'll need to research the bikes and be sure to look at the wheels, drivetrain, brakes, and braze-ons.

Those 40mm racing tyres are not suitable for commuting. A tough 28-32mm seems to be about right for all-weather commuting on rough roads.
Given the amount of clearance you need for these tyres (+ fenders), racing style caliper brakes are not deep enough, but you can get long drop calipers made for light-touring/sport bikes. I use these on an old style all-round road bike, and find they give better modulation (control) than the cantelever brakes on my touring bike, and the stopping power is every bit as good. The Shimano 105 version is recomended.

Cyclo cross gearing is often a low-ratio double (36/48) or sometimes a triple. Both are suitable for general purpose road riding, but you may want to customise the gearing to give exactly the ratios you need.

There are some production sport bike of sufficient quality, and you can also get some fairly good value frames which you build up. The advantage of a custom build is not that you use the very best components, but that you can put your money where it really counts (headset, bottom bracket, wheels), and use cheaper or even used components for bars/stem/post, and any other non-bearing part.

Soma do a sport frame for about $500.
https://www.somafab.com/extrasmoothie.html

You will have to check out the usual suspects at Bianchi, Trek, Jamis etc to see if they still do a sport model with long drop calipers. They seem to be switching to cantelevers in order to fit wider tyres for more touring capability.

When I was looking for a new bike I decided on a Trek X01 cyclocross bike. It allows me to but racks and panniers on it. I haven't tried mounting fenders, but the braze-ons are there. Great all around bike, most of the time I leave the cyclocross tires on it for riding locally and on rails-to-trails. When I'm going to do any long road ride, I switch tires.

One thing on the Trek, I did upgrade the shifters as I was having alot of trouble getting it to shift into the small ring. That's the only problem I've had with the bike. From my point of view, you can't go wrong with a cyclocross.

I am getting a Fuji Cross for this purpose tomorrow (I hope). I will be putting fenders on it but no panniers/rack. I use a backpack and have for the last 4 years. Obviously lights, water bottles, etc.

I am also changing the rear cassette to an 11-34 and all the changes that follow that. But otherwise the bike will be stock.