I think this is a very good idea, although it is a good idea to combine grid everyone...

Because when i was in juniors i was by far the biggest junior, and it was much harder for me to keep with Dylan Jewell the 9 year old...It makes it a lot easier on the heavier riders...

If you combine grid, one there will be more ppl on the grid which is a lot more fun, and it still gives the heavier riders the chance to compete with everyone else and see how they go (but being pointed differently)

just my oppinion
Sam Phillips #26