BMX

After contacting several bmx companies and wheel builders in the UK, all I heard was I needed to spend somewhere between £140-£280 for a single 20'' wheel to be build that would have a disc brake hub mount option. I then found these useful screw on disc brake adaptors that can be fitted to the rear thread on hubs: www.youtube.com/watch?v=5g_-LSBYWXU and on urbanvelo.org/montano-velo-fixed-hub-disc-adapter/

The only ones I can find being sold in the UK are by DT-Swiss Arai to disc brake adapter. They are slightly wider and have a grub screw at the side to offer a better hold to the hub. www.sjscycles.co.uk currently have them in stock. They have 2 versions available, a 140 and a 145 for an OLN 98 / TD - unsure what exactly that means - anyone know if either will be fine for a standard sized bmx threaded 14mm hub?

 £20 each seems a little steep considering you'll need 4. Has anyone seen any cheaper available in the UK?  

Understand they'll be fine on 2 wheels on one side of the kart, but the other side will need to be glued and perhaps even welded on as they'll want to unwind when you break.