BMX race frames in 2021

Author: Bruce at LUXBMX  Date Posted:17 August 2021 

Buying a BMX frame, where to start? 

Since the birth of BMX racing in the 1970s, there have been distinct periods in BMX race frame design and geometry that have been dictated by things like track design, innovation and  material availability. The first frames were predominantly steel and generally short, even in the pro sized frames. Unbelievable as it is, a Pro sized frame in 1980 would run a 20 inch top tube, or even shorter. Looking at that in the modern context, we see expert frames at around this size, or longer. The smallest Pro frames start at 20.5 inches, though we do see some brands pushing their Expert XL frames to 20.9 inches. Times have definitely changed!

What this illustrates is two trends appearing since what I call the “modern” era of BMX, which for me starts around the time that BMX racing debuted at the Olympics in 2008. It’s a neat intersection of time where BMX racing started taking to the 8m hill on a regular basis, with the higher speeds and general increasing in size of the corners and jumps seeing frame geometry and design become standardised to a certain extent. At this period in time, a Pro XXL across the brands still tended to be 21.5 inches in top tube length. Pro XL and Pro at 21 and 20.5 respectively. 


When comparing frames from one brand to another, you could be pretty confident that you were comparing apples to apples because on say a Pro XXL frame from X brand, you would have the same top tube length from brand Y. This made weighing up the pros and cons of frames from different manufactures pretty easy. Not so much anymore as the lines between sizes have become really blurred.

With a little look back at the 70s and 80s, BMX bikes were also pretty standardised in size, with micros, minis and junior sized frames being pretty exotic. If you look back through any old school shots, you’ll see kids on a mish mash of bikes, and if they were little kids, on bikes that were inevitably too big for them. This changed around the mid to late 80s when the Australian race market matured a little and “youth” frames became more available. Still, they were predominantly custom builds and not available to be purchased as a complete bike. 

Shifting to the past 3 to 5 years though, we have seen a move into another era in frame design with the emergence of carbon fibre and further broadening of frame sizing, with the 20.9 Expert XL frame mentioned above being a clear example. In the first part of the last decade, the longest Expert XL wouldn’t push over a 20 inch top tube. Now this “size” can range from 19.7 inches, to 20.9 inches. What this means for race customers looking for a frame change is that no longer is a Pro XXL a Pro XXL, if that makes sense? Ditto for Expert XL. What you really need to look at is the top tube length in the specs. On the flip side, a rider isn’t a “certain” frame size now, with frame designations like Expert XL having such a broad range. One inch is a massive variation and stretch for a rider. So again, when looking at upgrading a frame for a growing child, just don’t assume that they need to move up from a Junior to a Expert, though this is a natural progression (and a safe one), make sure to triple check the top tube length on the frame they are currently riding and then the one you are looking to move to. 


Making the big jump

This becomes a problem when the customer is jumping across brands when up-sizing. Within brands the size progression is set to a certain extent and the customer is usually comfortable with the geometry of that model range that they are currently on. But as stated, an Expert XL is not an Expert XL. This problem is exasperated when parents look at jumping a frame size, commonly jumping from Junior to Expert XL, or Expert to Pro. In the first example, a racer could go from an 18.5 frame to a 20.7 frame. A massive jump. We see this when kids are chasing a certain brand or colour. Ditto for the Expert to Pro. A rider could jump from 19.5 to 20.9 if not paying particular attention to specs and the parents have been advised that the kid should be on a Pro bike. Be it from a coach, or a good intentioned parent on the sideline. 


Another trend to look for in 2021 is the push on longer frames into the 22 and 23 inch top tube length. For sure we’ve seen this type of top tube length over the years, but the past 5 we’ve definitely seen more legitimate manufacturers pushing their top level frames to this length, with a corresponding increase in rear length to suit. Brands like DK, Stay Strong, Radio and Meybo all have offerings in this size currently. With the later brand, Meybo, seemingly at the forefront of this movement. As mentioned previously, a Pro XXL frame was pretty fixed at 21.5 inches for the top tube for a long time, though these naming conventions are now more fluid, with some Pro XXL frames coming in at 21.75 inches, which is their only offering (with their Pro XL having a 21 inch top tube. Speedco as an example). While brands like Chase have a Pro XXL at 21.5, and a 21.75 inch frame that they designate a Pro XXL+. 

This has led to some confusion in the market as customers need to look beyond the designations of Pro XL, Pro XXL, and refer to instead the actual top tube length when comparing frames and not all Pro XXLs are the same. Especially when, like we see in the junior frames, a rider is jumping across brands and a Meybo Pro XL is actually a traditional Pro XXL size at 21.5 inches. I think they were running out of Xs when labeling their 22, 22.5 and 23 inch frames. Speaking of Meybo, their HSX range frames are so dialed that these fixed rear end frames have differing rear ends (chainstay lengths) specific to the top tube size. This is high attention to detail and geometry design, especially when looking at their new carbon models. Most manufacturers use a common rear end length as this cuts the costs as they only require one mould. Having dedicated rear ends for each size is quite the investment, and commitment to design. It’s the sort of thing we really dig here at LUX.

What this ultimately means is that taller riders over 6 feet aren’t restricted to a small (for them) frame that has long been a tradition. A trend that has been embraced by European countries where you see some of their riders in teams all around 6 feet tall as BMX becomes entrenched in the supercross era of 8m hills and 50+ kph speeds. As the rider/athlete shape changes, so does frame design, meaning that racers can now find a frame comfortable for them without compromising.

What next for frame design? Disc brakes are definitely a trend that is here to stay. No matter how little we actually use a brake in BMX racing, the precise fingertip control, and clean aesthetic of deleting the brake posts means that (we feel) that this is a trend that’s here to stay. One major company we know of is looking at, on their pro sized frames, deleting the traditional cable linear brakes (and associated hardware) to run just disc brakes. 

And of course, the change in materials across brands sees some manufacturers exclusively offering carbon fibre frames only, while other brands have a mix of alloy and carbon frames. For this decade, we can see carbon fibre frames becoming more and more dominant at the upper end. Again, design and manufacturing flexibility is leading this change when using carbon fibre over alloy tubing as it has a lot more freedom when it comes to manufacturing. Carbon fibre allows for precise engineering of a frame and who knows what the 3D printing world will bring. 

When looking at upgrading your BMX race frame, LUXBMX has Australia’s largest range of brands and sizes at hand, as well as a wealth of BMX knowledge to be able to answer all of your questions when it comes to race frames and gear.


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