I think a bicycle trip is a GREAT idea. I've been on a couple with Rangers and Pathfidners and they were a BLAST!! Here are a few things we learned the hard way:
Dogs . . .
especially farm dogs which aren't tied up. Once we had a dog follow us for 20km - eventually a Guider trailing us in a car had to take the dog back to its farm!. We met a couple of dogs were weren't friendly but fortunately they didn't try chasing us very far. So be careful!!!
Make sure the last person in your line of bikers is wearing one of those fluorescent orange triangle thingys . . . it really helps make motorists award of the bikes! On the trip with the Pathfinders I also found myself telling the girls to stay together several times . . . we had a couple of cyclists who were really fit and had great bikes and tended to zoom way ahead of the rest of us.
Surprisingly enough, we had a hard time with water on a couple of the longer treks. Some of the gas stations or convenience stores wouldn't let us fill our water bottles unless we bough something. On the other hand, one place we stopped for water turned out to be a little family operated chocolate factory - not only did we get water, but a tour of the factory, free "imperfect" chocolates and ice cream!
Even though we trained all summer for one of th trips I was on, none of us were in superb shape. And even though we tried very hard, it was difficult to carry all the necessary equipment with us on our bikes. What we settled for in the end was everyone carrying their own personal gear and their share of the food in their panniers, etc and one Guider in a car carried the tents, tarps, and larger cooking utensils. That worked out pretty well.
Having it play leapfrog/shadowing your cycling group can be VERY useful. In case of an accident such as we had on one trip when a girl some how managed to shred a tire on her bike. As we had an extra bike in the car she just switched without loosing too much time - then changed the tire after setting up our campsite later that nite.