Daspydyr 

The FSA is a compact double (50/34). My bike is a DuraAce 53/39. I have tried but can't build enough strength to climb a class 2 grade. I am hoping that the compact double will give me the gearing to pull the grade. Thanks in advance for the comments.

jimc101

You may want to clarify which Dura-Ace you have, as 7600 is/was the track groupset.

For the BB30, no groupset cares what BB spec you are using, but your frame does, if your frame doesn't have a BB30 spec BB, it's not going to fit.

Daspydyr 

FSA SLK Carbon, 39/53 teeth, with a FSA MEGA EXO is listed as the standard crank and BB for this model on Bikepedia. It is the Dura Ace bike, but FSA had some parts on the bike. I bought it used. It seems the crank, seat post and handlebar are replacements from the original specs.

achoo

I *really* don't like FSA's "flavor of the week" approach to bottom brackets - each crankset has a different type of bottom bracket. WHY!?!?!?!

What crankset is on the bike now? If it has a Shimano Hollowtech II crankset, you can replace it with any other Shimano Hollowtech II crankset. You can find Tiagra 10-speed compact cranks for under $80 online.

Or, if you like a more classic look, get a 10-speed Campy alloy crankset and bottom bracket:

Campagnolo Veloce Power-Torque CT Bicycle Chainset - 10 Speed Sports & Leisure | ProBikeKit.com
Campagnolo CX Power Torque Bottom Bracket Outboard Cups Sports & Leisure | ProBikeKit.com

02Giant 

If the bike originally had the Mega EXO, it is not compatible with the BB30.

Drew Eckhardt 

BB386EVO is a way to put a 30mm spindle in a BSA frame which helps win gram counting bench races because that's sufficient diameter to make an aluminum spindle work. It'll also work with BB30/PF30 frames which reduces SKU count, increases profits, and allows FSA corporate executives to fulfill their fiduciary duty to share holders.

The thinner non-drive side bearing on the later MegaExo bottom brackets provides clearance for larger crank arms which makes hollow arms a viable alternative over solid.

Flyingblind9

If you already have a DuraAce crankset, I am assuming your bottom bracket is a Hollowtech II style, which means you cannot install a bb30 crankset because it has a 30mm spindle going through the bearings where yours from what I can tell should be 24mm. Hollowtech II has bearing cups that thread into the frame where bb30's bearings are pressed directly into the frame. Your frame will determine what new cranksets you can get if you are considering changing your crankset. Depending on the year of the shimano components, many of their cranksets between the compact and standard variants have the same radial span between the spiders and the chainring bolts so you could just put compact rings replacing the larger ones.

Daspydyr 

Replacing the current rings with compact rings would probably be the easiest for me. Would the "shorter rings" have any problems with the front derailer?

Flyingblind9

You would need to adjust the front derailleur. Ideally the outer cage of the derailleur should be parallel to the large ring and the bottom part of the outer portion of the cage should be 1 to 3 mm above the chain wheel's teeth. Otherwise your chain could jump off of the rings. When new rings are installed do a quick visual to see if it's still within proper tolerances.

GuitarBob

Perhaps the easiest way to change gearing might be to change the cassette, assuming that you're now running something that has a fairly narrow range (say ~11-25). If you move to a cassette with a winder range (~12-32) perhaps that might be enough to get you up the hill?

To do that with some Shimano rear derailleurs, though, you'd need the long cage version. I'm sure that last bit is correct with Ultegra 6800, but I am not sure about Dura Ace, so be sure to double-check.