I’m in a dilemma. Jnr – 7yo – we have discovered has outgrown his Islabike Beinn 20 small He’s small for his size but is now the correct size – 55cm inside leg – for a Beinn 20 Large or Frog 55. Now, these are quoted as 6-7yo bikes, and although appreciate the sizing is more important than the approx age bracket, its costly if he grows out of them quickly.

Should I risk a bigger Beinn 24 / Frog 68 or am I abusing my child?

if you ride non technical stuff get the bigger bike
If you ride technical stuff dont as it wont be “chuckable”

ie my MTB is 17″ my hybrid is 21″ both fit but i would never ride 21 offroad for i would die.

Well here’s the thing he rides to school and races MTB/cyclocross.

Having been to the o2 Team Sky experience today and attempt thier “wahoo” time trail on thier Sky frog road bikes he wants one of those as well of course, but there’s no way I’m getting him two bikes when he could do it all on one MTB. Mean I know, but he also needs to realise I have to leave a bit for the food bill.

Can’t you just swap a seatpost or stem. 20″ wheels are just that, so wait until he’s propoerly sized for a 24″ (which won’t be long).

Kids bikes grow in 4″ jumps, I can’t imagine why anyone would go from a 20″ to another 20″ (unless its to a BMX 😈 )

Well, this is the thing it makes more sense to get him the bigger bike.

I seem to recall my son riding a 24″ bike before he was tall enough but at that age they grow so quickly it probably only took a couple of months for him to grow into it.

The other alternative would be to buy another secondhand 20″ bike as a stop gap. In my experience ,of buying and selling kids bikes you lose very little if anything so needn’t cost anything.