I've introduced cycling as a way of life and racing to my two kids. One went off to college and ran her University's cycling team for 3 years (while racing herself). Now she bike commutes to her job in DC. The other just finished his high school sophomore season in the Colorado League and commutes to school by bike through the Wyoming winter. They both began racing young, initially with no more training than riding around town and some family road rides (including tandem time -- an awesome way to get them started young). But once they were a bit serious and willing, I'd take them out on the weekends, riding from home. I have the advantage (mtb trails nearby) and attitude that 9 out of 10 rides begin from the doorstep. I'd either go out before they were ready to start their day or after my ride with them was done. They were either asleep, dithering over their breakfast, or eating lunch while I was doing some "hard" miles. It becomes complicated if you need to drive somewhere to hit the trails -- I don't, so it's easy to be efficient with my time. They're included and ride as much as they want and I ride as much as I want. The kids also nordic ski race and since we have to drive for that (albeit only 10 miles), we were limited by what they could do -- when they were done, we were done. However, they quickly became better than their parents so that wasn't a problem for long (unlike the bike side of things).
So in summary, my tactic was to ride from the house -- no wasted time driving somewhere and I could tack on my miles and intensity on either side of their ride. Can't really do that if you need to leave your kids hanging out in the middle of nowhere at some distant trailhead while you try to tack on some extra miles. And there's always the trainer in the basement when they're hanging with friends or need some time away from Mom and Dad!
