Joined: Sep 2015
Posts: 1,300
Likes: 210
From: Ottawa, Ontario, Canada
Bikes: TrueNorth CX bike, 88 Bianchi Strada (currently Sturmey'd), Yess World Cup race BMX, Pure Cruiser race BMX, RSD Mayor v3 Fatbike
So what I'm trying to convey is that 451 is now labeled as, in addition to 20" with fractional sizing, 20" with decimal sizing but branding on the tire of OS20.
Because bike manufacturers hate us they also claim that, for no reason they've disclosed, OS20 at 451mm is not compatible with the fractional sizing 451mm.
Back to the original question, 22" for freestyle BMX is 457 BSD.
You're likely to be able to fit a 22", but you may be restricted to narrower tires.