Tri or Bi-cycle?

Not really a post, just a random thought. I'm seeing kids his age still riding tri-cycles and I wonder if he started riding a bicycle(with training wheels) earlier than usual? He's been riding one for the past 7 months now, so he started when he was 2 yrs 8 mos or so.

The last time he was out with it, he was doing circus monkey tricks on it - riding tummy down on the seat, feet up in the air! After seeing that, we've been considering taking the training wheels off and letting him have a go at it. Too early? Only one way to find out :-)