Cyclocross - compact cranks?

I know this has been brought up before, and I read through the archived stuff, but....I'm going to swap out my cranks on a new Moto Fantom Pro to some compact road cranks (34/50), since I'm using this for mostly road riding (rural/mixed surface). I'm trying to stay under $200, and what I've come up with is FSA energy for $164 at bikeisland.com, and Truvativ rouleur2.2 gxp road at Cambriabikes. Any suggestions about this, since I'm just getting back into cyclin after 15 yrs and things have changed. Any insight is appreciated, thanks.

They are both good cranks and BB systems. ... or you could just change the chainrings?

If the crank is any good I would just change the rings and save some coin...

If the crank is any good, I would just get a new set of rings and save some coin...

I've got a Redline Conquest Pro coming in this week. I'm switching the little ring to a 34T and the cassette to an 11-27 SRAM. If that's not enough range, SRAM Rival compact cranksets can be had for less than $160. (I suspect the chainring/cassette change will be plenty.)

For people like me, who ride a lot in the mountains/foothills, a compact makes more sense than a close-ratio CX crank.

kinda on the same topic here,

I'm looking at getting a cross bike, the one I'm looking at comes with a road compact, is it very common on cross bikes to use a 50/34?
What is the advantage of having the typical cx chainrings (48/38 ish)

34 is too low and 50 is too high to the point of being useless, you'll hardly ever want to use a ring that large. A 48 is still on the large side, you'll find yourself in your small ring most of the time. The gears you want most for racing are in the middle range of your 34 50 and you will find yourself shifting your front derailleur often, and its a big awkward shift between those rings. It will suck. A typical, and ideal IMHO, double setup is 36 46 if you have a 110 bcd crank. You could keep your investment minimal with just a 44 or 46t ring replacement and keep your 34, a little low but workable, you won't really need your lowest gears very often, but you also won't be undergeared for a sprint off the start line either. 38 48 is also common but you'll want a pretty big cassette in the back because you'll be overgeared, even a lot of the pros don't require a 48, you will still be in the small ring most of the time. Basically you want to keep your front shifts to a minimum and make them easy in the mud and a 10 t spread is about the ideal max. Ideal- go 36 46, or 34-44 or 46 depending on the cassettes you have available. Dont forget that you will soon want an extra set of wheels for the pit, flats are common especially with clinchers, so that means an extra cassette.

This is of course assuming that you will be racing that cx rig, where your concerns are easy shifts when you're seeing double and running when its faster than riding a low gear. Otherwise you are really asking about a sport touring/commute bike that can handle fat tires. In that case your 34 50 is fine. If you're not racing, well its just not cyclocross.

And, since the original poster SAID this bike is for road riding (not cyclocross) . . .

This is of course assuming that you will be racing that cx rig, where your concerns are easy shifts when you're seeing double and running when its faster than riding a low gear. Otherwise you are really asking about a sport touring/commute bike that can handle fat tires. In that case your 34 50 is fine. If you're not racing, well its just not cyclocross.

well, I certainly would like to give racing a try, looks like a blast, maybe I'll invest in a bunch of chainrings and mess around until I find a combo I like. The bike will also be used as a commuter/trailer pulling bike, but even then, I doubt I'd need a bigger gear than a 46-12 or so. Thanks for the explanation Zen.

weel, after looking around and watching ebay, I stumbled on a set of sram force carbon compacts for $200 which is a killer price. 34/50, and since I don't race and live in Vermont and am in the hills all the time I'm pretty sure I'm gonna love that 34, and it sure is fun still having some chainring left when you're bombing down one of those long hills, so I think the 50 might be fine too. Anyone want to buy a Truvativ Elita cross crank set, 39/48, with 40miles on it? Bryan