6-9 is actually quite a big age range in terms of ability to sit and listen. Add to that they will have been in school all day forced to do ‘boring stuff’. They go to beavers with the preconceived idea that they’ll get to be hyper with their mates. A nerdy bloke pitching up and trying to tell them too many facts will do their nut in and you only need to loose a quarter of them before you will have lost the lot.
Think about what you want to tell them, then lob out all the dry facts, then half the rest and you have a chance.
A pimp carbon road bike they can fawn all over (have a clunker bike to compare the weight to)
Some silly lycra to laugh at
The fact that your feet are in silly carbon shoes and attached to your pedals will freak them out
Maybe a bit of gnarly footage of a high speed descent
Distances is worthwhile only if you can compare to something very local – kids of that age have an incredibly limited understanding of distances outside of their immediate experience.
Could you ‘play’ at being a peleton? Simulate a Cav leadout train for example.
A great big pile of food to represent how many calories a rider will use in 3 weeks.
Trying to explain the points system for the KoM will loose them – red spotted jersey for best climber will suffice even if you want to go into that much detail.
Good luck.