x2 on the knowing effort rather than speed. That speed may be just because you have a good draft pulling you along

Gotta put in the plug for the dual Garmin setup. We love our dual 510's. Share the speed/cadence and individual HR monitors. Stoker has learned that tapping out the Captain is not a good thing so I can sometimes call out my HR and inspire a bit more production from the back seat.

For long day rides we just make sure the batteries are fully charged and then leave them on all day with never a problem. Really the only problem we have had is the stoker scrambling screen settings.