he means wide enough cage for coping with 11 speeds without rubbing in either the high or low position. the drop won't be a problem.
No, I mean one which can cope with the drop, since the road triples come with a 50t outer; 26t between outer and granny can be tricky to set up. I'm pretty sure he wouldn't be using 11-speed, since it's exclusive to Campag and that doesn't seem to be on his shopping list, and nobody needs 11-speed anyway. If it were my build, I'd probably stick to 9-speed for now as there is more chance of getting decent second hand shifters in both drop bar and flat bar formats.
No, I mean one which can cope with the drop, since the road triples come with a 50t outer; 26t between outer and granny can be tricky to set up. I'm pretty sure he wouldn't be using 11-speed, since it's exclusive to Campag and that doesn't seem to be on his shopping list, and nobody needs 11-speed anyway. If it were my build, I'd probably stick to 9-speed for now as there is more chance of getting decent second hand shifters in both drop bar and flat bar formats.
Cassette swaps are indeed easy, but shifting is compromised if you go from road cassettes to MTB cassettes, since you end up spending a lot of time trying to get an MTB rear dérailleur to shift on the faraway sprockets of the road cassette.
Incidentally, 10-speed cassettes are actually narrower than 9-speed, so FD chain rub in extreme gears is easier to avoid.