I'm building up a frame with a Centaur CT 34/50 crank and an 8sp 13-30 cassette using downtube friction shifters. I need a front derailleur, and I'm wondering how well the Centaur FD made for a compact double will work with a wide chain. I'd like to use an 8sp chain since they're so cheap and reliable, but I could go 9 sp. Still, this front derailleur is designed for a 10 speed, so I'm concerned the extra chain width will result in either too much rubbing, or too much trimming.
Any thoughts? ("Search" wasn't working for me today, so forgive me if this has been discussed previously)