I have been riding my first road bike for a couple seasons now, and am starting to get the itch to upgrade some of the components. I have a 2010 Specialized Secteur Comp with a Shimano 105 gruppo. I have already upgraded wheels and tires so I am thinking of stepping up to a Ultegra or DA crankset.

My current crank is a compact Shimano FC-R600 with BB, I have no idea what size BB this is.. What is all involved in changing cranksets? Can I upgrade to either Ultegra or DA without changing any other components?

Thanks!

Ultegra or DA cranks will work with your BB but if you install a nicer crank you might as well get a nicer BB too.

The nicer crank and BB won't make you any faster.

Don't bother changing that crankset unless you want different gearing.

I was using an R600 and switched to a 6700-series 53/39. Both cranksets shift great, and I don't think I'd be able to tell them apart if it weren't for the different gear ratios.

If you're not going to change the ratios, or you'd stick with the same BB size (the Secteur has regular English threading, right?), keep using that R600 until the teeth wear down. It's a nice crank.

Your current crank is 2-piece, there's no BB involved. (Strictly speaking, it is involved, but it's built into the right crankarm.)

You need a couple of specialized tools, Shimano TL-FC16 and TL-FC32. I think you can use ParkTool BBT-22 in place of TL-FC16.

Then you take out your crank, put it on eBay, and install a new one. Procedures involved in installing the new crank depend on the model, but you will most likely need BBT-22 again, and possibly other tools.

EDIT: I stand corrected: you can't use BBT-22 in place of TL-FC16, and I don't think you need TL-FC16 at all to remove the crank, it's called on just to install it.

^^^^

An Allen wrench (I forget what size) and a Park Tool BBT-9 are all you need to remove that Shimano Hollowtech II crank and its bottom bracket.
https://www.parktool.com/product/bott...ket-tool-bbt-9

It's easy. Really, even I can change a crankset in five minutes (if that), not counting readjusting the FD (which some pro mechanics have said isn't necessary when they change from standard to compact between stages).