What size is a BMX tube? It's a good question and to give a quick answer it's a 20 inch diameter. With widths generally ranging from 1.75 to 2.4 (depending on the year of BMX and the discipline of BMX you're talking about). So a tube that ranges from 20 x 1.75 - 2.40 would cover most sizes.


...Generally speaking that is

However, to go into the deeper nuances of BMX inner tube sizes, we need to look at the sport itself a little. The universal tyre diameter of a traditional BMX is 20". But over time as the sport developed, so to have BMX variants and wheel sizes (therefore BMX tube sizes). 


But it does depend...

At the smaller end BMXs these days can range from 16", 18" and 24" (yes, 24" is bigger than 20" we'll come onto that in a minute). These are designed to accommodate riders of different sizes and ages. Which is great. These smaller bikes have helped countless younger riders get into BMX way before a 20" bike is possible to ride. Which in turn helps the sport to develop, progress and more people having more fun. 



Hold on. You said 24"? Yup, we're talking about a racing or cruiser BMX. You see it's not always about the wheel size in BMX, it's the bikes geometry that dictates its target audience and use.

Even more confusing are that 22" and 24" are now becoming more popular for adults too. So it's not always about the wheel size, it's the geometry of the BMX that allows different people to enjoy different aspects and disciplines of BMX.


You see BMX is not one size fits all!

Which brings us onto the key point. The term 'BMX' covers a lot of different disciplines, therefore the bike and inner tube sizes vary. 

Briefly, older BMXs of the 80s would use a more 20" x 1.75 tube. But as the sport developed into the 90s widths grew making 20 x 1.95 more popular. Then around the turn of the millennium your regular BMX tube size would be needing to fit 20 x 2.125.


Yes, but what about today's BMX tube size?

As we move further toward the present day, things got wider. Up to 20 x 2.5 in some cases. Depending on the riding you do and the characteristics the of the tyre you need. So too does the tube size change with the tyre.

This wasn't much of a problem say in the 90s and 00s because the typical BMX tube of that time would be 20 x 1.75 - 2.125. 

Now what we're seeing is perhaps a divide between inner tubes. Some cover old skool sizes, some mid skool sizes and some cover new skool sizes.


Okay, so whats the answer in my case?

So to answer the question of what size is a BMX tube, it depends on your BMX, it's tyres and what tubes you'll need. Gone has the know it all reply of 'this size will fit'. As we have more specific bikes for the job and sports develop, traditional answers might not always be best. 

Asking the question of what size is a BMX tube? The better answer is to know where to look for the answer yourself as you already have it.


How do I know what size tube my BMX needs?

Simply take a look on the side of the tyre (not previous inner tube) you are replacing the inner tube of. You might see something like:

  • 20 x 1.75
  • 20 x 1.90
  • 20 x 1.95
  • 20 x 2.00
  • 20 x 2.125
  • 20 x 2.20
  • 20 x 2.25
  • 20 x 2.30
  • 20 x 2.35
  • 20 x 2.40
  • 20 x 2.45
  • 20 x 2.50


Great, so where do I find my next BMX inner tube? (Shameless plug!)

Now you're armed with your exact BMX tyre size (not a general rule of thumb of old), you can look for the tube that fits it! Here is a link to some great BMX tubes we have covering all of the above and more to get your started:


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