Originally Posted by
Andrew R Stewart
Well, when the chain is new the 1/4" of take up will be enough to tension a chain that has a 1/2" pitch. But as the chain wears this ability can become too little take up over time. .....
To clarify, and disagree a bit.
While Andrew mentioned 1/2" pitch, I suspect he meant chains with a half link, since bike chains are 1/2" pitch.
That means that you can shorten chain by 1/2" instead of the normal 1", divide that between the upper an lower loops and you get the 1/4" travel needed.
While Andrew is concerned about stretch, it's manageable because should you start out with the BB all the way forward and the chain stretched, you could cut out 1/2" and adjust the BB to just slightly forward of the rearmost position.
BTW- On a well designed tandem, the distance between the BBs is set such that the eccentrics would be in mid-range.