We've decided to get DS a bike for his 8th birthday as he's outgrown his last one. I'm not sure what size to get him though. Everything I've read says 20" is for 6-9years and 24" is 9+ years. We did take him to decathlon and Smyths recently and the 20" seemed like it fit pretty well and the 24" would take a bit of growing into (maybe okay by the summer when he'll use it more). He's average height for his age. Obviously I don't want to get a new bike that he's going to grow out of super quickly because they are expensive.
Which size should I be getting for DS?