We’ve carried BMX bikes at the Brantford Cyclepath since day one. Many shops make the decision to not carry BMX bikes for one reason or another. We, on the other hand, can’t imagine our day without them. Many of our staff, both past and present, come from BMX backgrounds. I myself did a quick calculation and figured out that there has been a Haro branded bike in my life, to some degree, whether in a workplace or at home, pretty much EVERY DAY for thirty six years! I’d bet that that’s a longer run than most of the employees that work at Haro.
It would be a safe bet to say that the large majority of our customers, both young and old, once cruised around on a twenty inch BMX bike. Many cyclists who spend their time on the latest carbon road racing bikes and dual suspension mountain bikes have BMX DNA in their blood. It doesn’t take long before a conversation with a customer can potentially turn to “when I was fifteen I had an awesome Redline and we used to have these jumps over behind….”, followed by “man, I miss that bike….”
Enough reminiscing already. It’s 2017 and BMX has stood the test of time. Not bad for a segment of our sport that became sanctioned way back in 1974 with the creation of the National Bicycle League, with the start of BMX agreed to have taken place in California during the early 1970s. So, what’s up with these small wheeled bikes? How have they evolved since the massive BMX explosion of the 1980s? What makes them different than your old Redline?
We can easily split the modern BMX bike into at least two camps. Just as not every bike with a drop handlebar is a road bike, the same holds true for BMX bikes. Those that are made for racing are incredibly light and stiff with nimble geometries for fast handling and efficient use of power. (Sound familiar, roadies?) Their compact carbon or aluminium frames use a very long top tube and rear triangle to keep the front end pinned down. Tall, wide handlebars allow for a powerful pull and increased leverage against the bike. Carbon wheels and cranks offer maximum stiffness and weight reduction, just like their road racing brethren. And just like road and mountain bikes, clipless pedal systems are used. If you’ve never seen an advanced level BMX race, these bikes are incredibly fast.
The other category is a bit loose in it’s definition. Street. Park. Dirt. (Flatland freestyle is an entirely different discipline with a unique bike all it’s own.) Ideally, it can come down to tire choice determining which of the three a bike might fall under. The common traits when compared to a 1980’s bike are shared regardless of the terrain being ridden.
The seat tube length of a modern frame is smaller, making the frame lower in it’s overall height. This allows tricks such as tail whips (Google it) to be done without the danger of having your toes hook up on the rotating top tube. This is also the reason why seats are run as low to the frame as possible. (Yes, you can ride sitting down. You simply have to learn to tilt your pelvis forwards.) Top tube lengths vary and are usually decided by personal preference and usage despite a general guideline for rider height. A longer top tube length gives you more room to move yourself around between the bars and seat. A shorter top tube length allows the bike to rotate faster around the center axis, minimising any outward gyroscopic effect that a spinning trick might produce. As with modern mountain bikes and unlike BMX race bikes, shorter rear triangles are used here to allow the front end to come up easily. The more money you spend, the more 4130 cromoly steel is used as a material, creating a lighter, stronger frame. As with race bikes, taller wider handlebars with taller top loaded stems enable greater pull on the bike.
Tires are considerably wider than before. This was done for several reasons. A larger tire provides more grip due to increased surface area. The greater air volume, coupled with softer handlebar grips, allows more shock absorption which helps to decrease the chance of wrist fractures due to the increased stiffness that a compact frame creates. Higher air pressures allow the tire to roll faster and deflect less. Wider rims open up the carcass of the tire, creating a larger tire profile that has even more contact with the ground.
More expensive bikes use sealed cartridge bearings in the wheel hubs and headsets, reducing the chance of impacting a bearing due to, once again, the increased stiffness of a more compact frame. Most frames of this level use what is called an integrated headset, wherein the head tube of the frame acts as a bearing race, rather than having traditional upper and lower bearing cups pressed into the frame. This provides a lighter, stronger setup and eliminates the possibility of a frame tube deforming due to loose bearing cups.
If you’re an old school BMXer, you’ll no doubt have noticed that the sprockets on modern BMX bikes are really small. This is what designates a bike as street, park or dirt rather than race. For the most part, race bikes still use traditionally sized larger chain rings due to the fact that gearing ratios must still be changed according to the track and climate conditions on race day. The other bikes use smaller sprockets so that the front chain ring doesn’t come into contact with street ledges or the lip of a skatepark bowl, and makes it more difficult to “case” a dirt jump when misjudgement makes a rider come up short on a landing. The rear sprocket had to naturally be made smaller to retain a useful gear ratio, and is now a component of the hub, rather than the traditional threaded on freewheel of the past.
In the end it really doesn’t matter what type of BMX bike you have, whether it be modern or vintage. Most bikes easily cross over to multiple uses without changing anything. The main thing is to get out there on one and use your creativity to have a blast while getting a physically demanding workout. We’ll see you down at the park!