This year my wife and I bought a used tandem and have been having fun. We like long rides on our singles, but the tandem cockpit is uncomfortable for me. I'd like to put an extra-long stem on the front, and it looks like the longest you can get are adjustable stoker stems, some of which are the right size to clamp on a 1-1/8" steer tube (pictured).
Would that be dangerous? I assume the adjustment weakens the stem somewhat, but also they are built to withstand being used as stems, so it seems like it should be fine? If anyone has some actual knowledge (rather than my semi-informed speculation), I'd love to hear it. Thanks!