About this site
Why OS20BMX.com exists.
A rider-built reference for a wheel size we love—and one that should be much easier to understand and shop for.
How the site is made
Research first. Publish second.
Specifications come from primary sources. Manufacturer pages support product and compatibility claims whenever one is available.
Retail availability is checked by hand. Stock observations are dated and never presented as a live guarantee.
Uncertainty stays visible. Rider reports and rumors are labeled unconfirmed instead of being promoted to facts.
AI is an assistant, not a source. AI-assisted tools helped organize, draft, and build the first version of the site. I review and approve what is published; factual claims must trace to a source or clearly state what is not known.
Send the page URL, the correction, and a supporting source to corrections@os20bmx.com. Messages are reviewed, but not every submission will receive a reply.
Where OS20 fits
The vet rider. The returning rider. The first-timer.
“First-timer” means an adult coming to BMX for the first time. This is not a recommendation to put every young or growing rider on OS20. Youth bike choices should start with the rider’s current fit, growth, skill, coach or shop guidance, and class rules.
Maybe you raced in the 1980s or ’90s and are finding your way back. Maybe you are in your 40s, 50s, or beyond and getting on a BMX track for the first time.
From my point of view, that is where OS20 has a real role. The slightly larger wheel can give a bike a calmer, more stable feel without moving all the way to a 24-inch cruiser. It can still feel like a 20-inch BMX bike—just a little more settled underneath you.
This is not a promise that one wheel size is right for everybody. It is why OS20 made sense to me, and why I wanted one place where riders could learn what it is, what fits, and what is actually available.
What turned me onto OS20
The reading list that started it.
These articles and videos helped send me down the OS20 rabbit hole. They are worth exploring alongside the practical fit and parts information collected here.
Demystifying the OS20 Wheel Size
A clear early explanation of the 451 standard, why it exists, and why it found an audience among older racers.
OS20 — We’re All About It
A useful walk-through of the wheel size, the parts that make an OS20 build different, and the idea behind the platform.
OS20 Curious
A rider’s account of trying OS20, including the more settled feel and the challenge of finding compatible parts.
Learn All About the OS20 BMX Frame and Why You Need One!
Supercross BMX’s video introduction to its OS20 frame and the thinking behind the format.
Why You Need an OS20 Race Bike with John ‘Benters’ Bentley
A conversation with John ‘Benters’ Bentley about the case for an OS20 race bike.
Community source
Where riders trade information—and sometimes parts.
Private groups can surface useful leads that never reach normal retailer searches. Treat sale posts as rider-to-rider listings: confirm the seller, condition, exact 451 sizing, and availability before buying.