I have been thinking about buying a compact for my Soloist. I just want it for my half-dozen trips up to the Blue Ridge Mountains each summer, and I am happy with the 53-39 almost all of the time around home. I already own a nice set of carbon cranks, and would prefer not to spend another $400 on a crank I will use 6 times per year, and I also don't want to put a piece of crap on one of the nicer bikes I own. My question is, is it possible to replace only the chainrings without replacing the entire crankset? It looks like the 50-34 might be pretty close in relation to the existing bolt pattern, so I'm not sure if it will fit. What do you guys think?

ps- Sorry if this has been covered. I searched and I wasn't able to come up with anything useful.