Looking at the Planet X and Ribble Sportive. The lads 12 so it'll probably just last two seasons when I could then use it as a training bike.
We will go the self build way so by the time he hits the Junior ranks in four years time we'll have a good bike. And I'll have a good second bike using all the old bits or we could sell it on.
not helpful but;
I'd be putting the money into some good wheels, a HRM, some quality gears or forks.
He will need to size up fairly quickly so I'd stick with bargain basement frames that fit. Look at it this way, he wont be putting out enough watts to trouble any cheap frames in terms of flex.
We will be building with good kit, not top end but good enough. The frame will be a temporary host for the kit.
He is 12 and 5'7" I'm 5'8" so I'm guessing he'll be taller than me but it does mean I could use all the gear that gets replaced.
kinesis do junior/women specific race frames which might be an idea.
At 5'7" i'd buy him a 54, it would be a little long but he'd be able to ride it through to 5'10"-11"