What bike for this?

[dim]

Very nice bikes, the smallest frame may suit a 12 year old boy?
However the OP's max budget is £600 for a complete build.

If he contacts Light Blue in Cambridge, he may get one for that price .... I popped in yesterday to have a browse, and they have loads of bikes on sale ... (and loads of Surly's) ... here's the link:
http://www.townsends-lb.co.uk/products/bikes/

here's a disk trucker on ebay for £750 or best offer ... it's a 46cm and looks in good condition .... they may accept £600 ?
http://www.ebay.co.uk/itm/Surly-Disc-Trucker-46cm-/262730199080?
hash=item3d2bf0b028:g:A90AAOSwXeJYDLXe

 

[Reynard]

Have a look at the Wiggins range in Halfords. Sounds like the 26" Chartres hybrid might fit the bill, or else the Rouen 650 road bike. Am a short lady and tried them both as even the smallest ladies bikes were too big for me (I'm 4" 11'). Eventually bought the road bike, but they're both very nice. You could even buy both on that budget, as they're on a promo at the moment

 

[Chris2014]

Okay, thanks. The input is much appreciated.