Originally Posted by pocky

Both the Schwinn and the Burley tandem are drop bar. Schwinnie has an 8-bend Modolo X-Tenos drop bar on a 56cm frame -- erring on the side of small and nimble for me, I think, but she's got a long geometry. I keep the stem a couple inches below the saddle. I'll ride her in the drops when we're going far and fast, but most of the rest of the time I'm on the hoods. I don't think I ride the tandem enough for it to be making any difference to my knee.

The mountain bike and the Kona are flat-bar (actually slight riser bar). I keep the Kona stem about an inch or two below the saddle, but with the riser, the grips are about even with the saddle, maybe an inch below. I've got a 150mm long stem on there, so I'm pretty far forward. (With a shorter or higher stem, the Kona feels far too different from the Schwinn, in an unpleasant way.) The MTB usually has the seat a bit lower than the stem for gnarly terrain, but it's got a quick-release seatclamp so I'll crank it up to normal height if I'm riding flat stuff. I don't think I ride MTB often enough for it to be making any difference to my knee.

I suspect I am pushing too much gear -- I'm pretty sure I stand WAY too much even on the geared bikes, probably just out of habit from the fixed gear being my daily driver, but I also suspect the problem is starting from a stop in too high a gear. I usually start on the right foot, but I'm trying to alternate it to the left. If my theory is correct, this should help. But starting in a lower gear and spinning more in general sounds like it would make a lot of sense.

I ride clipless SPD with 5-degree float on all my bikes, including the mountain bike and the tandem. Have several pairs of shoes -- two BMX-style for the daily drive, a pair of SPD sandals for the summer, and a pair of rigid MTB race shoes for MTB and long rides. No idea how to tune the cleat alignment other than "this feels centered to me". I don't know if there's any way to learn that outside of a proper bike fitting.