We've had 3 Co-Motions. All performed flawlessly. I would highly recommend Co-Motion's to anyone looking for a high-quality performance tandem. Our Calfee (carbon/boron) is head & shoulders better than any tandem we've ever been on (in our opinion)...of course, it also cost about as much as all 3 Co-Mo's combined! It's considerably lighter than any of our others, AND stiffer AND smoother. Everything we wanted in a frame. We have zero experience with ti tandem frames, although I talked with numerous tandem teams on Litespeed's & Lynskey's, as we considered ti before we bought our Calfee. All the Litespeed owners I talked with were very pleased with their bikes, but almost unanimously said they would do Calfee's if they had the chance to do over. The few Lynskey owners I talked with (there aren't too many Lynskey tandems out there) were all very pleased with theirs & none indicated that they wanted anything different. Ti/Carbon is definitely interesting to say the least.
I would like to see the component list Co-Mo are using to achieve sub 20 lbs. It would be interesting to know how much the bare frame weighs. Our Calfee weighs 26 ride ready including pedals, heavier wheels, heavy saddles, 145mm dropout & 28c clincher tires. Our bare frame weighs 5 lbs & change. We did order ours extra stiff. Some of the tubes are larger than stock to achieve this added stiffness (an extra pound or so & a few hundred $$). I've seen claims of Calfee's weighing 23 lbs built & Paketa's at 22. Both of these had wheels that would fold up like a pretzel under us & saddles that wouldn't make my a$$ too happy. This may all be fine for others (lightweight soft pedaling teams), but not realistic for us. It's definitely exciting to see the numbers on the scales keep dropping with every new frame that comes out! The real comparison is frame weight vs frame weight. I am also inflicted with "weight-weenieitis", but only if performance, comfort & durability aren't sacrificed.
Charlie
"Life is Short...Ride Long!"