Updated on April 5, 2022
What Material Is Bmx Bikes Made Out Of
A BMX BIKE FRAME’S ANATOMY
The frame is the most crucial component of any BMX bike, since it determines how the bicycle feels to the rider and, more significantly, how it performs when riding.
All BMX bike frames are designed to combine maximum strength with minimal weight. Several factors play a role in attaining this, including the materials used in bike frame manufacturing and how they are used.
Choosing a framework is more difficult than it appears. Weight, strength, impact resistance, rigidity, lifespan, shape, and riding quality are all elements to consider when choosing a frame.
Many BMX bike shops provide one-size-fits-all bikes, but frame size is important if you wish to compete in BMX racing.
Above the forks, the length of the top tube from the saddle tube to the centre of the headset tube is most essential. The longer the tube must be, the taller you are. There are numerous online bike size charts websites that can assist you in determining which size is appropriate for you.
Choosing a frame is also influenced by a number of other criteria, such as your height, weight, and riding style.
This article will go through the material used in BMX bike steel frame as well as what to look for when purchasing a frame.
BMX bike frames are made up of a variety of materials. They’re all formed of tubes, but the way they’re built and interconnected can make all the difference.
Seamless tubes are preferable, and their weight-to-strength ratio can be modified by thickening at high-stress places such as joints.
Although frames composite structures are frequently joined, most tubes are integrated into the simple bicycle frame by machine or hand welding.
For added strength, short-sleeved lugs can be wrapped around joints and brazed into place with brass. The bicycle frame are primed and coloured after alignment inspections.
1020 Steel Steel comes in a variety of colours and textures, but 1020 steel is the most prevalent choice for budget BMX bike frames. It is heavier and less durable than other materials, but it is less expensive. As a result, several manufacturers provide a steel/Chromoly mix (see below), with the downtube being built of stronger Chromoly because it is the most stressed portion of the frame. They’re ideal for younger riders since they allow them to have a taste of the sport without having to spend a lot of money.
Another prevalent material used in BMX bike frame construction is carbon steel. Although carbon high-tensile steel is a strong and long-lasting material, it is not the lightest. Younger riders will benefit from BMX bike frames built of high-tensile steel because they are less expensive when learning the sport.
Fibre made of carbon
Carbon steel strands can be bonded together to make a bike frame that is both strong and light. Carbon fibre bicycle frames have the disadvantage of being more expensive and more fragile. Because it is laminated, the completed product can tolerate a lot of bending and severe handling.
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Steel with chromium
Chromoly, a steel alloy of chrome and molybdenum, is one of the most frequent materials used in BMX bike frame construction. It’s light than carbon, has a high strength-to-weight ratio, and can withstand years of heavy use. Chromoly, on the other hand, comes in a variety of grades. Because inexpensive Chromoly is weaker, the tubes are thickened to compensate, eliminating the weight savings. Many bike frames are made of a combination of Chromoly and 2010 iron, which helps to keep costs down.
Aluminium used to be prohibitively expensive, but it is now considerably more affordable and frequently utilised in bike frames. Aluminum 6061 is lightweight and sturdy, although it is less flexible than other metals. Riders who ride their bikes on the road prefer aluminium frames. To make them more inexpensive, some frames are built of aluminium alloys containing scandium or magnesium.
Titanium is one of the most costly metals and is used to make top-of-the-line road and cross-country mountain bikes. It is much lightweight but just as robust. It also has the benefit of being both durable and adaptable.
What to Check for When Purchasing a Frame
The bicycle frame is still being shaped by manufacturing methods and market trends. Butting is still employed in the production of bicycle frames, albeit it isn’t as common as it once was. Meanwhile, steel, the long-serving workhorse, is increasingly being supplanted by aluminium, its sturdy relative that is becoming less expensive by the year. So, what are your criteria for selecting a frame? Is the frame for next year inherently better than the one for this year?
Manufacturers have experimented with a variety of unique metals and technologies in order to shave valuable grammes from frame designs. However, the price you pay is inversely proportionate to the weight of your bicycle. It weights less the more you pay.
Aggressive angles should, in theory, result in aggressive ride characteristics. Angles that are more relaxed result in a more relaxed ride. Which is the best option for you? The answer is highly dependent on how often time you spend riding. If you ride frequently and aren’t eager to fight the road or trail, opt for a head tube with a relaxed geometry of 70 or 71 degrees. The head-tube angle on more aggressive bikes is 72 or 73 degrees.
Tubing with a plain gauge
Despite advances in materials, production processes, and design, plain-gauge frame tubing is still the best bang for the money. These are tubes that are straight, sturdy, and easy to build without relying on butting (see below), oversizing, or strange mixtures. As a result, they are less expensive. Plain-gauge tubes weigh more than butted tubes, according to those who are “serious” about cycling. True, however the difference can be as little as three or four pounds in some cases. If you’re just out for a stroll through town or on a trail and not trying to conquer a mountain, the weight difference won’t matter.
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A good bike manufacturer’s goal is to place the materials where you need it. And you’ll need the material that gets the most wear and tear on the bike frame—at the ends of the numerous tubes. Butting is the term for this procedure.
Internal Butting—Because butting is buried within the tube, you won’t see it when looking at it. So, how can you tell whether the bike has been butted? It’s a significant selling feature for bike manufacturers, so they’ll tell you.
External butting—Adding material to the exterior of the tube is an older, more expensive method. This is a rare occurrence nowadays. On rare occasions, though, an extended weld will be visible. (For more information, see below.)
A frame tube can be butted in one of two ways.
Extra material is permitted inside at each side of the pipe due to the tube’s form. The entire tube wall thickness can be decreased by enlarging these portions of the tube, saving weight.
Triple Butting—The double butting method is developed by stepping down the material at the tube’s ends to save even more weight. This means that the butting starts off thick, double-butted, before being thinned and stepping down to the typical tube wall thickness. The inside of the tube appears to be three terraced rice farms on a hillside in a cutaway.
Frame tubes can be joined in one of three ways:
Use the same material as the tube to fuse them together (TIG welding).
Using silver or brass, braze the tubes together.
To attach the tubes, use lugs.
Despite the fact that each process has its supporters, TIG welding is used on practically all bikes except the very highest-end models. This method is quite low-cost and produces an excellent, solid weld. Examine the welds on a bike, however. You’ll notice that good bikes have a thick, even weld all the way around the tube. The welds on department store bikes are thin and patchy, normally wiped down on the top, bottom, and sides, but with open sections in between.
Extended Welds—Adding welding material towards the end of a tube is an affordable technique to add material. This is usually an elliptical circle or a double line that extends from the joint to approximately an inch down the tube before disappearing. What’s the issue with this approach? The heat utilised in this operation has the potential to corrode the tube. Manufacturers will heat-treat the entire tube again after welding, basically baking it, to bring the metal back up to par. This procedure, while successful, is less substantial than actually creating the butting as the tube is dragged out.
What other aspects should I think about?
How long will you keep your bicycle?
Steel oxidises (rusts) more quickly than aluminium. Steel, on the other hand, can withstand more stress in the long term than aluminium. Which is the superior option? Aluminum may be a better option if you live in a damp region. Is it a dry climate? Steel is a good material to work with.
What is your current weight?
If you weigh more over 170-pounds, you’ll need a bike with more strength. This may require an extra pound of frame weight, but it will be well worth it in the long term. Steel and titanium are also superior for larger riders due to a property known as elongation. They are able to flex further without breaking.
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Is money a consideration?
Despite the fact that the costs of aluminium and titanium have decreased, steel remains the most affordable metal. However, because most bikers prefer the reduced weight of aluminium or carbon fibre, manufacturers are developing aluminium or carbon fibre bikes that are more inexpensive. Titanium? It’s still pricey.
Hey, all I am Joe Marino I love to ride bikes and teach others how to ride them. Most of my articles are about which bike is best for others. I am passionate about cycling and it shows, whether I am writing about a $25 bicycle from any random website or a $5000 Santa Cruz.
I have always been the guy who gets calls from friends while at work asking which bike they should buy. I have written about the best city bike for commuting, the best folding bike for use on public transit, and even what to keep in mind when shopping for kids’ bikes.
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