I raced a lot in the 1980s. Mostly track and crits in the NE. Now I'm thinking of trying cyclocross. I was joking with some friends the other day that this would have been easier 10 years ago. Now there seem to be so many choices within the cyclocross bike options. I'm not looking for particular bike recommendations necessarily, but I'm interested in people's thoughts on the following choices. (I have a budget of $2,000 to $3,000. I've surveyed all the big name manufacturers for ideas: Cannondale, Focus, Giant, Ridley, Trek, Jamis, Fiji, Blue, Masi.)
Buy frame and build up vs. buy a complete bike
Buy lower priced bike (<$2,000) and a nice set of race wheels vs. buy a nicer bike and use the stock equipment for racing
If buying a complete bike, there are several choices. For under $3,000, you can get 2 or 3, but not all 4. Ideas?
Mechanical vs. hydraulic?
2 x 11 vs. 1 x 11?
tubes vs. tubeless vs. tubulars? (tubulars would drive me back to the lower priced bike with separate wheels choice)
There's no "right answer" for CX. It really depends on you, your riding style, and the kind of courses you're going to race. A complete bike is almost always a better deal than building and it's tough to spec out a build without any experience (some component choices will likely be significantly different than what you'd pick for a crit bike). Personally, I'd scour the used market to find a starter bike, race it for a season to get a feel for what you like/don't like, then buy a good bike next season knowing much better what will best fit your needs.
I don't see much point in thru axles for CX. As for brakes, you want brakes that have good modulation and will keep working through the race, but you don't need gobs of stopping power. Few CX races are ever lost because someone didn't brake enough Unless your races are mud-fests, even a good set of cantis is more than adequate.
Drivetrain is a very personal choice. I am running 1x10 this year - partly because it makes it easy to convert to SS and run the SS race at the end of the day. Our courses typically don't have big hills or long fast gravel segments, so I can live with a relatively tight gear range. I'm avoiding 11 speed because our sandy courses eat chains and cassettes faster than CX fans eat waffles. I'll gladly sacrifice having an 11T cog that I won't need 99% of the time for the price savings replacing 10 speed components.
The biggest ROI in CX is tires and wheels. You can't beat tubulars for performance, but if you go that route you'll probably want at least two wheelsets with different tires to cover different course conditions (I know some folks who have three or four sets). In addition to the stock clincher wheelset that came with the bike, I have a good set of tubulars with a tire that will cover course conditions I see most often. I normally run the tubulars, but I keep the clinchers with a couple of other tire choices to cover unusual conditions and to serve as pit wheels. I also train on the clinchers since they're a lot cheaper to replace than the tubs.
Good luck with your racing. I think you're going to regret not getting into CX sooner
2013 Kona Jake, 2015 Kona Jake the Snake, 2008 Kona Major Jake, 2013 Kona Jake the Snake, 2006 Kona Kula, 2012 Ridley Excalibur, 2008 Surly Long Haul Trucker, 2001 LeMond Buenos Aires, 1984 Pinarello Gran Turismo, 1982 Trek 614
With that kind of budget I'm going to assume that you intend to be a fairly serious racer. If this isn't true, get a sub $2000 bike and spend the rest on beer. You can still count that as a cyclocross-related expense. If you don't drink, spend it on frites.
So, if you're serious....
Building a bike from the frame up usually isn't economical, but in this case there may be good reasons to consider it -- mostly if you want a lot of components that aren't available on a stock bike. In this regard, take a look at Gevenalle. People with a high budget tend to look for high end components from one of the big 3, but Gevenalle makes CX-specific components that are lighter, stronger, less expensive and in many ways functionally better for cyclocross racing. If you like that route, it gives you a decent budget for other things like wheels.
Otherwise, there's not nearly as much difference between the frame and components on a $3000 bike and the frame and components on a $2000 bike as there is between a $1000 wheelset and whatever stock wheelset the $3000 bike comes with. Plus, there are many reasons why having a second wheelset is useful. So that part of the decision is easy.
Thru axles? I don't know much about this. The mountain bike guys love them. I expect that in a few years they will start to become ubiquitous. Now, it kind of limits your wheel choices. I'd pass.
Mechanical vs. hydraulic? You aren't even considering cantilevers? For discs, I'd say hydraulic is the way to go. Most mechanical disc brakes have serious issues when the conditions are sufficient to wear down the pads significantly during a race.
2 x 11 vs. 1 x 11? Do you really need 11? I ran 1x10 last year. This year I'm going with 2x9. There's an argument to be made either way for 1x vs 2x. The gear range of a 1x system is plenty, but CX involves a lot of rapid speed changes, so the 2x can be helpful in that regard.
tubes vs. tubeless vs. tubulars? (tubulars would drive me back to the lower priced bike with separate wheels choice) I run tubes, but by all accounts tubular is the best available if price isn't a concern.