My problem is that I have limited gear selection on the small crankgear (34-tooth), as the chain starts to rub the outboard cage of the front derailleur, when I get to the four smaller cassette gears.

If I adjust the FD to stop its rubbing, I find that the chain then rubs the inside face of the big crankgear (50). Due to this, it seems I only have six available speeds on the small crank gear.

When I'm on the big crankgear, I can run on the 9-smaller gears with out issue, but get inboard cage rubs if I try to run the biggest rear gear when on the front.

Yes, I know I'm not supposed to "cross-gear" in these ways, but that's a lot easier to swallow on my other bikes which are triples.

This bike is being built from scratch - my first, and also my first "double". This is a Motobecane Le Champion SL frame, with 10-spd Ultegra cassette, Ultegra 6600 GS rear, and 6600 front derailleurs. The crankset is a SRAM Apex, 50/34, 110 BCD. Chain is 10-spd, 6600 as well.

People talk about 10-speed gear trains as having 20-speeds, but in this case I wind up with only 15 usable combinations. In contrast, my 27-speed gear trains on my Specialized Sequoia, delivers closer to 25-speeds.

What's the deal here on these 10-speed doubles?

Thanks in advance!