Last updated: January 2nd, 2023
Bicycles have several dozen parts, but most are made of just a few materials.
Some, like rubber tires, are obvious and standard. But others, especially frame materials, are varied and surprisingly controversial among cyclists.
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This is what bicycles are made of
Virtually all modern bicycle frames are made of aluminum, steel, carbon fiber, or (less commonly) titanium. Components are principally steel, aluminum, rubber, and plastic. There are also small amounts of foam, vinyls, and various lubricants.
Frames and rigid forks are simple. They’re often just a single material. But components involve dozens of precise moving parts, which in turn requires several other materials. And below is a list of just about all of them.
No bike (to my knowledge) uses every possible material, but all bikes use several of these:
- Carbon fiber (composite)
- Foam (for grips and saddle padding)
- Leather (for grips and saddles)
- Rubber (primarily for tires and brake pads)
- Liquids (like brake fluid, suspension oil, and various greases/lubricants)
- Magnesium (sometimes in pedals and suspension forks; very rarely in frames)
- Wood (now a novelty for frames, but common many decades ago)
What are electric bicycles made of? Most electric bicycles have aluminum frames, and a few use steel. Carbon fiber is becoming more common as e-bikes gain popularity among mountain and road bikers.
However, quality batteries and motors are already expensive, and carbon adds a further premium on top of them. The whole package is cost-prohibitive for many cyclists, so it will probably remain rare out a tiny, top-tier slice of the e-bike market.
What materials are mountain bikes made of? Most low- and mid-range mountain bikes are aluminum. Carbon is more popular on high-end models. Steel mountain bikes are still available, but have not been common since the 1990s.
Titanium MTB frames are also available, but you won’t often find one on production bikes. Many MTB riders who would have chosen titanium in years past now opt for carbon, instead.
What is the best material for a bike frame?
Aluminum bicycles frames are usually the best value, but high-quality steel or carbon fiber frames may last longer since they don’t have fatigue limits. Steel is especially easy to repair. Many believe aluminum has the harshest ride quality, but that’s somewhat controversial.
For sport cyclists, aluminum gives the best combination of light weight and low price. However, it won’t have the potentially unlimited lifespan of steel, nor the extremely light weight and vibration reduction of good carbon frames.
If you plan to spend around $2,000 or more, then carbon fiber will get you the lightest possible bike and arguably the best ride quality. That’s true of mountain, road, and even hybrid fitness bikes. Titanium is also popular on very high-end mountain and road bikes, but it’s rare to find a worthwhile one under $3,000.
It’s worth noting that pure carbon fiber isn’t used. Those fine fibers are delicate and hard to work with. Rather, they’re coated in a resin (essentially a glue) that holds them together in sheets. That’s why we call it a “composite.”
There’s a lot more to the manufacturing process, too. In brief, engineers arrange the fibers specific patterns to help the frame/component either flex or resist flexing where appropriate.
Steel is the best choice for touring, commuting, or all-around practical cycling. It is more durable than aluminum and carbon fiber, and easier to repair if needed. That’s especially important for bikes that carry luggage or cargo, and are often knocked around on public bike racks.
Steel-frame bikes exist at all price ranges. Brooklyn Bicycle is a great brand for practical riding, Jamis makes some sportier options, and Rivendell is one my favorite boutique brands if money’s no object.
Most bicycles throughout history have been made of steel. Aluminum and carbon fiber are arguably more prevalent today, and may perform better for road and mounting biking. But steel remains highly popular, and is still the best choice for most of us.
As its fans say, “steel is real!”
What are the lightest bicycles made of?
All of the lightest production bicycles are made of carbon fiber. That includes their frames, fork, and virtually ever other non-friction component. Bikes like this are often under 15 lbs, but may run upwards of $10,000.
But exactly how light can a bike be?
Someone with a lot of ingenuity, time, and (presumably) spare cash pulled off a sub-6-lb custom bike. Does it ride well or last very long? The jury’s out. But it’s quite a technical feat in any case, especially when you consider that a typical frame and fork may weight 4-6 lbs.
As for production bikes, it’s surprisingly easy to find ones under 6.8 kg. Most brands with large racing programs (think Specialized, Trek, Bianchi, Canyon, and the like) all have something for you—that is, provided you have the bankroll. Why 6.8 kg? That’s the weight minimum for racing in events under UCI, cycling’s international governing body.
All the above are carbon fiber through and through. But it turns out that steel frames can yield a lighter bike than you might have thought. This custom steel bike got down to an astonishing 9.94 lbs—with the help of carbon fiber components, of course.
Unusual frame materials
Once in a while, manufacturers experiment with unconventional frame materials like magnesium, plastic, and even wood. These were usually small production runs in the 1990s, which generally didn’t perform well enough to justify their high prices.
The goal of unconventional bike materials is usually the holy grail of engineering: strong and light and cheap. It’s often said that you can only pick two of those. Some brands have tried to have their cake and eat it, too, but those experiments have never been commercially successful.
More recently, some small brands have sold bamboo or wood bikes. Projects like these are more about sustainability or social enterprise than performance, which is perfectly good. They just don’t offer practical benefits that standard materials don’t. (Fun fact: back in the mid-1800s, the predecessors of today’s bikes commonly had wood frames. But, like just about everything else from the mid-1800s, we’ve found better alternatives.)
Are any bicycles made from recycled materials? Every few years, a start-up develops a bike from recycled steel, aluminum, or even plastic. On one hand, turning especially troublesome waste in a bicycle is the best sort of recycling I can image. On the other hand, it’s an incredibly expensive process—and still energy-intensive—which essentially rules it out for mass production.
They’re great as brand marketing or awareness-raising, but so far, they’re not viable on a commercial scale.
The best way to get a “recycled” bike is simply to buy a used one. No manufacturing (or re-manufacturing) process will ever be as environmentally sound as simply not making something in the first place.