If you don't want to fork out on a new compact chainset, front mech, chain, cassette etc then why not go for a 13-29 cassette in Veloce with a slick dura ace chain.
Do your sums and compare this combo with a 50-34 12-25 which most compact riders use. Now people are getting wse and going for an 11-25 on the 50-34 but there s a jump somwhere on that ratio. All of my riding pals have switched to 50-34 and most wnet for the 12-25 but all hate the jump from 50-34 when droping before a climb.
So what dd I do. I took off my 12-25 and stuck on a 13-29 in its place, maintaing the 50-39. Ok so I lose the 53-12 and settle for the 53-13 but I gain the 29 for really steep climbs (marie blanque) between long hills. (somport, portalet), hence saving your legs.
What cn you now place with- well the 29, the 26 instead of having 25 as bottom. Now I can ride a 53-26 on a climb and really spin out at over 90rpm.
Living clsoe to the skirt of the pyrenees makes this a decent option and I can still kick it a close to 60kph on the flat with the 53-13. Well in te 80s didnt we ride 13-22 cassettes on a 42-52?? How often do you really use our 53-12?? In short the 13-29 53-39 is almost as good as a compact and far cheaper. Try it out...