Dave, Jamie is 12 and been riding Bedgebury, Swinley and even Wales since he was 8ish. It was only this year that I got him the full sus.
I'm with Matt, leave him on a hardtail for a bit (perhaps pimp that a bit ?). That way in a year or so if he's still into riding he'll be bigger and better equipped to go full sus.
And if you can't wait or indeed don't want to then checkout the Canyon Nerve. It comes in xs and is spot on for money and spec - I nearly ordered one for Jamie several times.
Lastly, if you want your son to get into riding then bring him out with the group, Jamie has been badgering me about Swinley so I may see about a group ride like Bedgebury on Sunday but to Swinley
Sent from my iPad using Tapatalk