All the facts on bicycle frame materials

“Steel bicycles weigh a tonne.” “Carbon breaks easily.” “Titanium isn’t worth the money.” “Aluminium bikes are cheap and crappy.”

As bike mechanics, we’ve worked with every kind of frame material. We’ve seen how they break, how they’re made, and which ones work best for different riders. But many myths still persist. You need a guide, and that’s what we’re here for.

First, the TLDR version:

STEEL

• Pros: Strong, comfy, repairable
• Cons: Heavy, prone to rust
• Best for: Touring, gravel, classics

ALUMINIUM

• Pros: Cheap, light
• Cons: Brittle, hard to repair
• Best for: Entry-level, budget builds

CARBON

• Pros: Light, stiff, customisable
• Cons: Pricey, can crack
• Best for: Racing, high-performance

TITANIUM

• Pros: Light, strong, won’t rust
• Cons: Expensive
• Best for: Premium builds

Overall: no one frame material is “best”. It depends on your riding style and budget. So before you make your next bike purchase, let’s get stuck into the facts on frames.

What’s the best bike frame material for commuting?

For a commuting bike, pick a metal frame, especially if you’re locking it up in public or at work where it might get knocked around.

Are steel bikes good for commuting? Absolutely. They’re durable, reliable and smooth to ride.

Is aluminium better for city bikes? If your budget doesn’t stretch to steel, then aluminium is a good backup.

Remember: don’t just go for the cheapest option. A cheap steel frame is heavy. A cheap aluminium frame rides like a tank. A cheap titanium frame… well, a good cheap titanium frame doesn't exist. We’ve had quite a few budget ti frames through the workshop, and they’re always full of manufacturing flaws.

Mechanic’s tip: make sure the frame has mounting points. There’s no point buying a commuter and then discovering that you can’t fit mud guards or a pannier rack on it.

What’s the best bike frame material for touring?

Metal frames will always be best for touring. But what’s best: steel, aluminium or titanium?

Steel, for three reasons.

1. Steel frames offer a smooth, bump-absorbing ride.
2. Steel frames are durable.
3. Steel frames can be repaired.

Do not underestimate the importance of repairability. If you find yourself in the middle of Uzbekistan with a broken steel frame, anyone with a welder will be able to patch you up and get you back on the road. If you’re riding aluminium, ti or carbon, however, you’ll be looking for a new bike instead.

Why do bikepackers love steel frames?

A steel frame absorbs a lot of vibrations over rough and unpredictable surfaces. Couple that with the fact that you can load it up and it can deal with dents and bingles, and steel is an ideal choice for bikepacking.

What’s the best bike frame material for road racing?

Is carbon the best bike frame material for road cycling?

Carbon is the lightest of all frame materials. Not only that, it can also be made into a very stiff frame, ideal for racing. (Badly made carbon frames, though, can end up being too rigid, resulting in a bone-jarring ride feel.)

Additionally, carbon can be made into any shape you want, ideal for aero frames and for those who want a particular aesthetic. (Which is most roadies, let’s face it.)

Do I need a carbon frame for racing?

This depends in part on what kind of racing you’re doing.

If you’re racing long, flat stages (not time trials), frame material isn’t as relevant as you’d think.

In hills stages, though, the differences start to show themselves, especially with a heavy or harsh frame, so we’d recommend going good-quality carbon if you can.

What’s the best bike frame material for gravel riding?

Is carbon good for gravel bikes?

For lightness, the best frame material for a gravel bike is either titanium or carbon.

Titanium is great for longevity, but carbon tends to be more affordable.

Budget too tight for either? Go for the always-reliable steel.

Steel vs aluminium for gravel — which is better?

While many major brands now offer aluminium gravel bikes, from a mechanic’s point of view, most of the ones we’ve seen have been less than impressive, so it's hard to recommend them as an option. Again, steel is the winner here.

Mechanic’s tip: strapping bikepacking bags on to a carbon frame? Strap movement plus dust and dirt can act as an abrasive on your frame. Make sure to cover these areas with protective patches to protect against frame damage.

What’s the best bike frame material for mountain biking?

Steel vs aluminium for MTB — what lasts longer?

For weight, ride comfort and durability, high-grade steel is the best choice.

Lightweight steel has its limitations, however. Pete’s custom mountain bike frame—which he had made by a frame builder as an experiment—is a good example. In his own words, "it flexed like a bastard, and broke easily.”

As it’s hard to find high-grade steel MTBs, most of your options will be either aluminium or carbon.

Carbon has a two-fold advantage over aluminium: it can be patched up if it’s damaged, and will give you a weight advantage if you’re racing.

Are carbon MTB frames strong enough?

Customers sometimes worry about using carbon frames off-road where there are rocks and roots and pointy things, but this is largely unfounded. These frames are usually manufactured to be reinforced at impact points.

What’s the best bike frame material for heavier riders?

Is steel better for heavy riders?

Not necessarily.

Carbon frames can actually handle bigger cyclists well. With metal frames, there's a limit to what you can do with the tubing. Carbon has no such limit, and thus can be shaped and manufactured to deal more easily with heavier loads and forces.

However, every frame has a weight limit, and these vary greatly between brands. Always make sure to check the specs before you buy.

This especially applies to boutique lightweight frames and components: make sure you’re well below their maximum weight limit.

What’s the best bike frame material for coastal/snowy/salty environments?

While most riders don’t have to think about their environment when it comes to their frame, it matters if you live near the coast or somewhere snowy where the roads get salted.

Does aluminium corrode near the ocean?

Yes.

So does steel.

That frame will eat itself into nothing but dust and shattered dreams.

Is titanium the best choice for coastal riding?

Yes.

Titanium is an inert metal: it does not rust.

Where traditional metals suffer badly, titanium will survive.

OK! So now you know what frames suit what kind of riding best. Let’s dive into exactly why.

Bike frame materials explained

First up, a note on metal definitions.

Although we refer to a frame as ‘steel’, ‘aluminium’ or ‘titanium’, that frame’s material will actually be an alloy.

An alloy is a combination of elements with at least one of those being metallic. All metal frames are therefore alloys as they all include other elements.

• Titanium frames are usually an alloy of titanium with aluminium and vanadium.
• Aluminium (if you consider Bauxite to be the natural version of aluminium, and for the sake of this blog, we will) is usually mixed with silicon or magnesium. Aluminium bike frames tend to be alloys such as 7005 and 6061.
• Unlike titanium ore and aluminium, which are natural elements (e.g. you can extract them from the earth), steel is a purely manufactured product. It’s created by combining iron with carbon, so it’s already an alloy even before it leaves the foundry. Steel bike frames are commonly alloys such as chromoly or stainless steel, but sometimes are just purely high-tensile steel.

Is steel a good bike frame material?

Pro: Strong, durable, shock-absorbing.

Con: Can be heavy.

Steel has a long history in bicycle manufacturing. The all-steel safety bicycle was developed in the 1870s as an alternative to the cast-iron penny-farthing, and the material continues to be popular over 150 years later. #steelisreal

Primarily known for its strength, steel also offers some elasticity – it will bend before it breaks. When made into a bike frame, this elasticity dampens bumps and vibrations to give the smooth ride that steel bikes are famous for.

Steel also has a major advantage in that it can easily be repaired.

Not all steel is created equal, however.

High-grade steel—the material that every manufacturer is trying to emulate overall—offers lightness, plushness and durability.

Cheap, high-tensile steel, on the other hand, makes a durable but very heavy frame. It will probably never break, but you’d better pray you never have to lift it over a fence, either.

Good-quality chromoly steel is far lighter than its cheaper counterparts without compromising strength, and can be made stronger again. People are often surprised by how light a Genesis bike is, and Pete’s custom-made steel roadie is just over 7kgs with pedals, which is pretty respectable for a bike with a steel frame and fork.

Overall, a steel bike can potentially last you a lifetime.

(As long as you don’t live by the sea.)

Are aluminium bike frames durable?

Pro: Can be cheap, generally light.

Con: Brittle, shorter lifespan, hard to repair.

Aluminium’s main claim to frame fame is its weight. In alloy form, it’s lighter than steel, and can be made even lighter than a mid-level carbon frame.

The trade-off is that aluminium isn’t as strong as other metals. Some frame manufacturers try to fix this by making oversized tubing and thicker tube walls (which sometimes results in a heavier frame, ironically negating any original weight saving).

Another downside is that aluminium has a shorter lifespan than steel. The more it flexes, the more fatigued it gets.

This brittleness also means that—unlike steel, carbon and titanium—once aluminium starts to bend, it usually breaks, and a broken aluminium frame is difficult to repair. Welding aluminium changes the metal’s structural properties, and weakens the surrounding area. (This is why factories need to chemically or thermally reset the frame after it’s been built, to realign the alloy’s grain.) If your aluminium frame breaks and is welded, the section immediately next to the weld is now far more likely to break – you’re essentially just moving the problem along the frame rather than solving it.

Because of this, most repairers won’t touch aluminium frames.

Is carbon best for road cycling?

Pro: Light, strong.

Con: Costs more.

When you think ‘carbon frame’, you usually think ‘expensive’. And that’s correct – good-quality carbon tends to be pricier than steel or aluminium.

For the cost, however, you get a frame that’s light and resilient, perfect when every gram counts.

Carbon can also be stronger than you’d think, though it won’t necessarily survive a dent that a steel frame can absorb.

If the worst does happen, though, it can usually be repaired.

But there’s an even better aspect to it.

Carbon can be put together in almost limitless ways. Unlike metal, which has to come from a foundry, carbon is a prefabricated material and can be made into practically any imaginable shape. Its fibres can be loaded and arranged in different ways to achieve different objectives – strength at high-load areas, flexibility in others. The frame builder has ultimate control over the ride quality, weight, design and stiffness. (This can be good or bad, depending on who it is.)

Custom carbon does comes at a price, and with this material you tend to get what you pay for. We see a lot of cheap unbranded carbon frames that have been purchased online; they’re usually riddled with manufacturing errors and, in some cases, are downright dangerous.

Make sure you’re buying something from a reputable frame manufacturer, not bikesbytemu.com.

Is a titanium bike frame worth the price?

Pro: Light, strong.

Con: Expensive.

For many riders, titanium is the holy grail of frame materials. It’s lighter than steel, and has a longer fatigue cycle. Unsurprisingly, it’s also the most expensive frame material on the market.

Titanium’s high price point is down to two factors:

1. the cost of the raw material
2. it’s harder to work with than other metals – the properties that make it durable also make it hard to weld.

So why is titanium such a great material for bikes? Mainly because of its strength-to-weight ratio; as titanium has the same strength and durability properties as steel but without the same weight, you get a lot of bang for your buck.

Like steel, titanium is excellent when it comes to shock absorption, leading to a more comfortable ride. It's also very resistant to impact, and tends to return to its original shape after a hit.

(We weren’t kidding about metal having a memory.)

How can I tell what my bicycle's frame is made of?

One thing people tend to do in bike shops is tap-tap-tap at the frames to work out what they’re made of.

Unsurprisingly, this method isn’t particularly reliable, so here’s our easy What’s My Frame? Guide.

1. Get a magnet and put it to the frame. If it sticks, it's steel.
2. Magnet doesn’t stick? Now check out the frame’s welds.
3. Are the welds big and chunky? It’s probably aluminium.
4. Are the welds small and neat? It’s most likely titanium.
5. No frame welds? It’s carbon. Ta-da!

Note: some manufacturers grind back the welds on their aluminium frames to make them nice and smooth. While it may look better, the problem is that the frame will then usually break because the material holding the tubes together (i.e., the weld) has been removed/reduced.

One major brand is notorious for doing this, which is why in the trade they're referred to as Crack 'n' Fail.

*cough*sorry if you ride one*cough*

A final note: are magnesium bike frames any good?

Magnesium bike frames break.

Magnesium is not only soft but also corrodes easily and needs surface treatments so it doesn’t oxidise. It's difficult to weld (Google 'magnesium fire'), and frames often requires additional reinforcing plates so they don’t fall apart.

So… yeah. Forget magnesium bike frames.

What’s the best bike frame material for me?

Steel = comfy, strong, repairable - your go-to for touring, gravel, and bikes that last decades

Titanium = light, durable, rust-proof; perfect for premium builds and salty coastal roads.

Carbon = stiff, feather-light, and customisable; ideal for racing, performance, and saving every gram.

Aluminium = light, cheap, gets the job done; entry-level and budget builds welcome here.

Magnesium = lol no

At the end of the day, the material matters less than the maker of the bike. The manufacturing process and design is what makes the difference between a beautiful machine and a sketchy deathtrap.

Choose wisely, and listen to your bike mechanic, not some rando on a forum.

FAQs on frame materials

Q: What is the strongest bike frame material?
A: Titanium and high-quality steel are the strongest, but carbon can be just as durable when made well.

Q: What’s the lightest bike frame material?
A: Carbon fibre is the lightest, followed closely by titanium.

Q: Which bike frame material lasts the longest?
A: Steel and titanium can last a lifetime with proper care. Aluminium has a shorter fatigue life.

Q: Are carbon bike frames fragile?
A: No. Quality carbon frames are strong and repairable, but they can be damaged by sharp impacts.

Q: Do aluminium bike frames break easily?
A: Not immediately, but aluminium fatigues faster than other materials and is very hard to repair.

Q: Is titanium worth the price?
A: Yes! Titanium offers an unmatched mix of light weight, comfort, strength and corrosion resistance.

Q: What’s the cheapest bike frame material?
A: Aluminium is usually the most affordable, though low-end steel frames are also inexpensive.

Q: What frame material is best for commuting?
A: Steel for comfort and repairability, aluminium for affordability, or titanium if you want a lifetime bike.