Went on a 20km ride with my 8yo daughter
Earlier this year I attempted a metric century but only made 72km.
My daughter was inspired and wants to do the 72km too. We ride to school regularly but she has never gone anywhere near that far. So as a test we rode from my Grandma's place to the local lake. 20km there and 20km back if she was up to it. She made it there ok but then we called the SAG wagon (Granddad) to pick her up.
It's a nice road. We saw about 5 cars and none of them passed too close. No magpies attacked my daughter which is a huge bonus in September in Australia.
Still, 20km is a good start. And I got to ride back at my own pace. :)
Her ride: http://www.strava.com/activities/84013747
My ride: http://www.strava.com/activities/83757998