Replace a 52/36 crankset with 50/34 I'm looking at purchasing a new bike with a 52/36 crankset on a 11-32 cassette. I've grown accustomed to a 50/34 crankset on the same cassete, and for the type of riding I do in the PNW (300-400ft hills regularly, 3000ft+ mountains monthly), I don't think I want to give up that lowest gear. It's not that I always rely on the lowest gear, it's just that want the option for days where I want to take it easy. I've been riding around on my current bike where I avoid using the lowest gear to simulate the 52/36 crankset and I've found that after a long day of riding I really like the option of spinning up a steeper hill.

So, I know I can swap out the crankset but will I have to swap out more than that? The 52/36 crankset is really the only thing keeping me from purchasing this new bike over something else that comes with a 50/34 crankset.

For the complete specs, this Canyon is what I'm currently considering.
You should not have to replace the entire crank-set. In general, a 'mid-compact' 52/36 crank will have a 110mm BCD spider, which allows 50 and 34 tooth rings to be installed.

The Ultegra FC-R8000 crank on the Canyon comes in 53-39, 52-36 and 50-34 versions, so you will be able to get the smaller rings for that specific crank.

The front derailleur may need to be dropped down slightly to adjust for the slightly smaller rings. 

Front derailleurs have a 'max capacity' spec which is the difference in tooth counts between the rings - typically 16 for a road group-set. Obviously this is not changed between 52/36 and 50/34 so the derailleur does not have to be replaced.

Updates:

As mentioned in comments the chain may need shortening.

You might need to remove the crank to get the small ring off, but no special tools are required with Shimano 2-piece cranks - just a couple of bolts on the non-drive side arm.