Originally Posted by
jrecoi
451 rims are available as racing BMX parts. In BMX use, they are referred to as 20 x 1 1/8, and the rims are available from Sun, Alex, in 28h, 32h, and 36h.
In order to run 406 rims, you'll need to change both the rims and the brakes, and won't take a tire larger than 1.75.
I was under the impression that 451 was 20 x 1 3/8 and most common on recumbents. Could be wrong though. But yes if you change wheel sizes the brakes will be an issue. It's a very long reach to a 406 rim of you currently have 451.