Would not be cost effective. Just about every tube length and angle would need changing.

I can see that happening. If only one person on the team loses interest or is injured, no more team. If a tandem takes a relationship where it's going, only faster, then perhaps someone's partnership got to the finish line before delivery.

I'm reminded of a story the builder of my first tandem told me. He had a couple who were having him build them a tandem. He wasn't cheap; his motto was "Why Pay Less?" He wondered why the husband was insistent that the stoker compartment be made bigger than was appropriate for the wife. He got his answer a few months after he delivered the tandem. The couple was getting a divorce and the husband already had a new stoker who just happened to fit the bike perfectly.

This seller had very specific requirements for this impressive build. The Cannondale Hollowgram cranks are not tandem-compatible, and he had to reverse the threads on three pedals. Wonder if he ordered the crank arms with the reverse threads or did a retrofit.

Sold for $10,300.I would want to test ride before buying, if I was spending that kind of $$$$$$

I didn't put it in my watch list, but noticed it was no longer listed.
I thought it had a little more time left and the seller had pulled it.
I am with you Joey, at that selling price, I would want to lay hands on it before committing to buy.
Last weekends trip to Bama got postponed due to weather, we have rescheduled with Jack for this Saturday and plan to demo a Calfee, a Supremo and a Speedster co-pilot, post ride thoughts to follow.

At 10 grand you might be able to part it out and make a profit.

Wow, now that would take some big stainless steel bearings to pull off!