Bicycle Mechanics - Crank / chain compatibility

Got a question, guys ...

I currently have a Campy compact crank and 10-speed drivetrain on my touring bike. But, I'm planning a hillier tour next summer amd want to get some lower gearing by replacing the crankset with a triple. Campy makes a triple crankset for the road, but it's granny has 30 teeth (only 4 fewer than my current compact). If I were to go with a mtn bike triple, I could easily get down to about 22 teeth on the granny. But mtn cranksets are all 9-speed from what I can see. Would my 10-speed chain work with a 9-speed crankset?

Yep. The part where the teeth fit is the same. It's the joints that have been narrowed.

Will your front brifter handle the triple? Dérailleur? There may be other issues, like pull ratio. But I don't know Campy well enough to comment that there is more to consider than the chain.

Don't underestimate that 4-tooth difference. And see if there are smaller rings that will fit the road triple. The chief difference between a road and MTB crank is the BCDs of the rings.

Thanks for the response DMF. Shifters shouldn't be an issue as they're bar ends (friction on the FD). Derailleur might need to be changed, but we'll see ...