The new fat mongoose Bmax frame has new school geometry and the others above are mountain bike frames, it was touch and go whether I could get these wheels into an old school bmx frame , Even though the wheels are 20" the OD with the tyres are 30mm larger than a standard bmx wheel (15mm top 15mm bottom) That's why I made it so the tyre is only 2mm from touching the bottom of the fork otherwise it would have sat too high at the front.