My wife and I are a typical 67 yo couple and ride a DaVinci design tandem with a 500 watt front hub motor. The motor is very stealth so unless you really payed attention, you would never see it. We can easily maintain 20+ mph for up to 25 miles. Steep up hill grades with both of us pedaling moderately hard, we can maintain 8 mph without really breaking much of a sweat.
I know we've probably caused a few nervous breakdowns with the "younger" set.
