Please anyone with a 22” and a 20” handy can you measure the diameter height of them both. Maybe please share a side by side photo. I’m trying to see if I have room for a 22” in the rear of my bike. Thanks in advance
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Why would you run a tire size that is basically non-existent? I would have to build and buy new wheels that are an extremely uncommon size which would mean sticking with potentially lower quality stuff or at least stuff with fewer options. I will have to run narrower tires and if I do run a brake then I would probably have issues there. Then if I have a need for a new tube or tire most shops aren't going to carry it and they would be hard to order. It all seems like downsides to me. If I wanted a bigger BMX bike I would go with a proper 24" which is a more common size but honestly I would probably stick with 20" like all the other BMX bikes.

All the adults I know who ride BMX ride 20" or I have seen people build up 26" and 29er stuff for cruising and such.

By 22", do you mean 451 bead seat diameter, or a different one?

20" is typically 406mm, so that's almost 2" difference, but 451 is also typically called 20". Also, 451 tires tend to be skinner and high pressure, as 451 is typically used for fast road riding, so the actual outside diameter is closer to 406-44 than the difference in bead seat diameter would indicate.

So - picking up on Duragrouch - The 451 size has been picked back up in racing as the "OS20" size, some people refer to it as "cheater size" as the wheel is bigger than the 20" classes allowed until this new name happened. There are a few good race tires and rims out there for it for sure. It's going to raise your bottom bracket and mess around with your geometry a little.

22" BMX is pretty common and tires and tubes are readily available. If not in stock at your LBS they can order them very easily. S&M, Fit, Subrosa, and Stolen just to name a few brads have 22" bikes or frames. The frames are closer to the geometry of a 20" than the companies can get with larger wheeled bikes.

Yes OS20 and 22" are the same rim diameter. It's like 700c and 29" same size rim just wider. OS20 uses 20x 13/8" tires and 22" uses 2.1-2.4" tires. One is for racing and one is for street/ park/ trails.

I know you can get them but I wouldn't say readily available. None of the shops I have worked for stocked tubes for it aside from one where towards the end we stocked them for the rad power crap coming in.

From one of the largest distributors QBP which does a lot of BMX stuff you have one tube option in a normal butyl tube and some Tubolito tubes and a single rim strip was well as one front and one rear wheel. No rims and no tires at all. Eastern which does nothing but BMX has zero stuff from what I saw (not saying they make good or bad stuff just commenting on a BMX only company). I get it does exist but not super common in the regular world.

Not quite - 20x 1 3/8 is expert size. Uses the same size wheels as mini BMX racing. I know it's should be the same, but the manufacturers claim that it isn't compatible. I haven't tested whether it is or not. They're labeling the tires as 20x2.1" but marking it OS20. This is because if they call it 22" then it can't be used in BMX class racing, only cruiser.

"Oh great oracle of Sheldon Brown, lend us your wisdom."

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.

457!! OK, that was not understood, that gives a much better understanding of things. I thought you were talking purely about 451 vs 406. So are you trying to fit 457 tires on 451 rims, or 451 tires on 457 rims?

I'm not the OP. @AtNjineer is trying to fit 457 tires and rims on a frame intended for 406.

Sorry, thanks. Ah, well, depends on how tall the section height. I wish the tire charts on sheldonbrown had either that or the outside diameter for each tire size. They do list the bead seat diameter and/or radius. I would take that for 457, add the same section height for the 406 tires he prefers, and that would give them the diameter they seek.

AtNjineer was banned, and the forum was better off for it.

I’m late to the party. I got here while looking for info to offer some BMX-related corrections for the Sheldon Brown tire sizing systems page.

It’s a narrow rims and tires versus wide rims and tires thing. Same 451 BSD, but mating wide tires to skinny rims (and vice-versa) seems like a bad idea, assuming it works at all.

Actually, the dividing line between class an cruiser is drawn at 22-1/2”. The USA BMX rule book says:

(above) I'm sure the current overlord at SheldonBrown, John Allen, will appreciate contributions. The site has continued to expand in knowledge after Sheldon's passing. How you get in touch with John is a mystery to me, I see no obvious link on the SB page.

John Allen made some updates to the SB Tire Sizing Systems page about a week ago and BMX sizes like OS20 and 18" x 1.0" (ISO 400, the bane of many a race parent) are now included. The kid-race fractional sizes (451 and 520) now have improved descriptions. While 457 (the 22" of this thread) now gets a proper BMX mention (and several additional street/park/freestyle widths), wires were crossed: the page states that it's also a racing cruiser size. I sent a follow up email to correct this a few days ago. Fingers crossed.

If you want to get in touch with John Allen, you can get his email address within a few clicks starting with his name in the revised-by line at the top of the article. (Emailing the general contact address on the SB website didn't get me anywhere, BTW.)

John Allen: I see that now. Hiding in plain sight. Thanks.

22" is more of a cruiser midlife crisis kind of bike. You can still do tricks on it, but the 20" is more versatile long term wise. At the end of the day, all wheel sizes are fun, but dont commit to the 22" if you want to still do stunts.