Need help identify my pit bike and what wheels to run.

[Radium]

Bought this pit bike, I have no idea what brand it is, The engine has Atomik on it but all i know is its a 125cc.

 

[Cordogs]

It’s probably an Atomik nitros by the look of that frame, and the fact it has the engine with it.
Are you rebuilding it?

 

[Cordogs]

Sorry I didn’t read the full title…

14” front and 12” rear would of been the original spec, but you can run what ever you like. Hope this helps.