26inch or 29inch for kids

[RobertWhitehead]

My opinion: Get the 9 year old a new bike but seriously consider 650B or even a mullet. I agree that a bike that's too big will be a death trap rather than a joy. I had a friend who's like 1.65m and he went ahead and bought himself a M Cannondale Lefty 29er. He could not keep up on any terrain and he said every time we finished some single track that he felt unsure on the bike - this coming from a hardcore DH rider. It's as Captain also mentioned, it doesn't have to be 29er, 26ers are still pretty much alive in the European countries so I won't write them off just yet 

[porqui]

For a little person you want less bike.

 

A 29er is a lot more bike than a 26er.

 

I would go with a 26er with a good wide handlebar.

 

26ers are not from the past they are just out of fashion.