We had our first anniversary of tandeming the other day, and in celebration (?) I shifted from nearly-in-phase (captain leading 5 degrees) to 90 degrees out of phase (captain leading).
Having read many endorsements of the out-of-phase life, but also a number of comments tending the other way, I decided to suggest a trial period, which we're now in. To summarize, the main points are: more even drive train wear, better feel of contribution for stoker, easier start/stop (?); harder to climb out of saddle, need awareness at speed bumps/humps, harder to communicate "through the pedals".
The idea is 2-3 months and then a decision, now that we've had a full year of in-phase.
- getting started takes a bit of getting used to, but not a big deal (we're "Proper Method" (tm) folks);
- when she really pushes (esp. out of saddle) and I don't, I feel myself being slid forward and back in the saddle
- down-shifts are quicker, in the sense that I [I]usually[I] had to shift down two, but up one. The second gear I had to shift down was to compensate for the speed lost to soft-pedaling. Without the gap in the power stroke, I can now shift down just one.
- I think our average speed is slightly higher (this has a lot to do with this particular team, I wouldn't expect it to generalize).
- I feel her power more - if I let up I almost feel her jerking my feet around. I think we had a slight drop in rotational speed (not enough to cause us to coast) at the low-power point in the stroke. Now that's gone.
- More of an opportunity for an aerobic workout. Doesn't make a lot of sense to me, but it doesn't have to. It's related to the notion of being able to feel her own power contribution better.
- A little getting used to starting (pedal position changed).
- I think she's made up her mind that we're not going back...
The communication through the pedals thing has never worked as well for us as for some other couples. We've not yet tried any significant hills, but I'm sure we'll get plenty of chance. I certainly wouldn't mind if I got a measurable increase in chain life.