I think Hora’s got a good point. (never thought I’d write that)
We took theg1 round Landegla blue a couple of times when he was 4 and it was way too much. It gave him negative feelings about cycling for years afterwards. Took a while to get him back into the cycling’s fun point of view.
Kids are all different, my daughter cycled with me for a few years, and now she has no interest in it. That’s not because we overdid it, she’d just rather go and play with her mates.
Jonathan makes a good point for longer rides, always have a plan B and C. We’ve cut a lot of rides short over the years.
Some kids like riding bikes, and some don’t. I love going out with my son, but if he doesn’t want to come along and do something else instead that’s fine also. My daughter rocks, but not on a bike. :)