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Carbon fiber vs. aluminum bike frames

By Bruce Lin

Published

Aluminum vs. carbon bike frames
The frame is a bicycle's heart and soul. It binds all the components together into a cohesive machine. It is the bike's identity. Without it, a bike is nothing. But what kind of soul should your bike have? Does it have a space-age carbon-fiber frame or an affordable aluminum frame? 

Most bike frames will be made of either steel, titanium, aluminum, or carbon fiber. Steel and titanium are the most popular options for custom and handmade bike building. Most modern bikes, however, are made from aluminum or carbon fiber.

How do you choose between aluminum and carbon fiber frames? Let's compare the key differences

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Are aluminum bikes harsh?

The conventional wisdom in cycling has been that aluminum is stiff and harsh, while carbon is compliant and smooth. However, this subjective thinking is a bit outdated. It was true 20 years ago when aluminum frames were unrefined. Aluminum is actually a fairly soft metal, so in the early days, builders used thick, oversized tubing for strength and durability. This made aluminum frames super-stiff — fine for racers but too harsh for everyday riders.

Ride quality has long been a claimed benefit of carbon frames. Carbon can be engineered to be stiff in certain directions and compliant in other directions. This means a carbon frame can be comfortable over bumps and rough roads while simultaneously being stiff enough in key areas for efficiency. Bike marketers love using the old “laterally stiff and vertically compliant” chestnut.

Cyclists in LA

Over the last couple of decades, improved technology has narrowed the comfort gap between aluminum and carbon. Manufacturers can now vary the shape of aluminum tubing throughout its length with hydroforming to achieve laterally stiff and vertically compliant ride characteristics. Frame tubes can be thinner — sometimes as thin as a soda can — in areas where compliance is desired and thicker where stiffness and strength are necessary. All this means that a modern aluminum frame isn’t significantly less comfortable on regular roads than its carbon counterparts.

Objectively quantifying the difference in comfort between two similar bikes is incredibly hard. Bike design has a huge influence over comfort. So do tires and touchpoints. If your bike feels harsh, wider tires with more supple casings and lower air pressure will make the greatest perceptible difference. Things like more compliant handlebars, seatposts, and thicker bar tape can make noticeable improvements too.

The bottom line: Carbon has a slight edge, but if comfort is your biggest concern, frame material is secondary to other, more important factors. Is the bike intended for road racing or endurance riding? Look at things like tire clearance, fit, and geometry. Ultimately, no matter the frame material, comfort is something that can always be fine-tuned or improved.

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Weight comparison: Carbon vs. aluminum bikes

Even if you’re not a “weight weenie,” a lighter bike can improve the riding experience. It’s possible to build very light and capable bikes out of either aluminum or carbon. However, a carbon frame will almost always be lighter than an aluminum equivalent. Few materials can come close to carbon fiber's strength-to-weight ratio.  

Using high-modulus carbon and clever engineering, designers are able to produce carbon bikes that are very strong, while being ludicrously light. Many major manufacturers now produce carbon road bikes that weigh less than 15 pounds complete, and cross-country mountain bikes weighing in around 20 pounds. 

Not all carbon is created equal though. Lower-grade (or modulus) carbon has more fillers, which reduces cost but adds weight. It is possible for a lower-modulus carbon frame to weigh more than a high-end aluminum frame. In this case, you get what you pay for. 

Of course, a frame only contributes to part of a bike's total weight. Components are the other half of the equation. A carbon frame with low-end components can weigh the same or more than a nice aluminum frame with high-end parts. Wheels make a huge difference in bike weight and how heavy it actually feels when riding.

The bottom line: With the right components, aluminum frames can still be competitively light, but if you’re looking for no-holds-barred lightweight performance, carbon is unbeatable.

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Why is a carbon bike more responsive?

Modern bikes are amazingly stiff and responsive without feeling punishingly harsh. When you push hard on the pedals or dive into a corner, a good frame needs stiffness to resist the torsional forces that rob you of power or derail your bike's handling. 

Does one material do this better than another? Technically, carbon comes out on top. With aluminum frames, manufacturers use different tube shapes and varying thicknesses to control the ride characteristics. But fundamentally, Carbon fiber simply has more potential for engineers to tune ride quality. By simply changing the carbon layup (the direction that carbon fibers are oriented), it can be made stiff in one specific direction, and in one specific area. 

Solo road rider in California

The bottom line: Both carbon and aluminum frames can be made to be responsive and stiff. The responsiveness and stiffness of carbon frames can be engineered and tuned to a higher level and it can be finely controlled, giving carbon a slight edge over aluminum. 

Are aluminum bikes more durable?

Many riders are afraid of damaging an expensive carbon frame. Carbon fiber's strength to weight ratio is higher than steel. And it has infinite fatigue life, so carbon isn't subject to damage from normal, long-term use. But, it is susceptible to damage from direct impact, as you'd experience in a big crash.

Fortunately, carbon can be easily repaired, and when done correctly, the repaired frame's performance and durability is indistinguishable from when it was new. That's something that can't be said for aluminum.

Two ladies riding mountain bikes

While aluminum frames cannot typically be repaired, they are less expensive to replace. Aluminum can also withstand some crashes and impacts and still be okay to ride. However, make sure you have your local bike shop check out your frame, if you're concerned it might be damaged. Dents in key areas can compromise an aluminum frame. Cracks can appear in welds that can eventually lead to frame failure.

While carbon fiber has an infinite fatigue life, aluminum frames won't last forever. Sometimes riders will talk about how they can notice how an old aluminum frame feels "softer" after years of riding. 

No matter your frame material, it's important to regularly inspect it to ensure it is safe. The simplest way to tell if carbon is cracked is to run a clean rag along the tubes to see if it snags on loose fibers. You can also tap on an area that's been impacted and listen to the sound — a dull "thwack" is a bad sign, but a clean, crisp "tick" might mean you're okay. Again, check with your friendly, local pro mechanic before assuming your bike is safe to ride.

Aluminum dents can vary from shallow cosmetic blemishes to deep dents. Ultimately, it’s always best to get your bike inspected by a trusted professional.

The bottom line: Any frame that’s properly cared for can last a long time. Bad luck and crashes can happen, and in these cases, aluminum might be more durable, but it's certainly cheaper to replace. Carbon might get damaged by impacts, but it can be repaired.  

Aluminum bikes are less expensive than carbon bikes

There’s no real contest here. Carbon is more expensive. There is more engineering required, the manufacturing process is more labor-intensive, and every frame requires a dedicated mold that further increases the cost. It's possible for aluminum frames to be built by machine, but carbon fiber layup is still done by hand. 

When considering bikes at an equal price point, an aluminum bike will generally have nicer components than a carbon bike. It is a balancing act between paying for frame quality and component quality. Remember, components are always easier to upgrade than frames.

The bottom line: Aluminum is cheaper. Whether or not that makes it better or worse can be a matter of taste. Good bikes are made at every price point. The lower cost of aluminum frames may free up your budget for higher-end components.

Carbon vs. aluminum: Which looks better?

Carbon fiber opened up new possibilities in bicycle design. The smooth curves and swooping shapes of today’s bikes were unimaginable in the era of steel and titanium.

Aluminum bike manufacturing has also gotten good enough to produce bikes that look a lot like their carbon counterparts. Hydroforming allows manufacturers to form aluminum frames into smooth aerodynamic shapes. Seamless welds can add to that smooth appearance, making some new aluminum frames almost indistinguishable from carbon at a distance.

Carbon and Aluminum Bikes

For some, welds can also be a mark of beauty. Perfect, clean, and even welds represent excellent craftsmanship. For some mountain bikers, thick, beefy welds can make a bike feel tough and ready for gnarly riding. 

Ultimately, a good-looking bike could be made out of anything if it’s done right. It's up to the rider, and if you're happy, that's all that matters. 

The bottom line: Beauty is in the eye of the beholder. Ride what you like and be happy!

Conclusion

Based on this info, ask yourself questions when choosing a new bike. What's your budget? Are you a competitive rider or are you more casual? How much does weight matter? Are you planning to crash a lot? Some riders simply don’t need carbon. Some can’t stand the thought of riding aluminum

Remember, though, that the most important part of a bike — even more so than the frame — is the rider. Pick the frame that you think can make you the happiest. That’s the best way to enjoy the ride.

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24 comments


  • I started on steel, then carbon and now aluminum. After 36 years, I honestly enjoyed riding all three for different reasons. But cycling is so much more than frame material. It’s gluing up my first set of tubulars, the sunrise hill repeats, cracking a tooth in a CAT5 crash and racing UPS trucks to the next stoplight. No one gives two shits what you ride so just go out and make memories.

    Glenn on

  • The Fun thing is “ riding your bike” ….. this is a subject like asking Vanilla or Chocolate ice cream sprinkles or Jimmy’s
    And yes Steel or Titanium…… a road bike will handle different than a Mtn bike downhill or cross country, gravel or road
    It’s your choice enjoy

    James Wilbur on

  • I own both carbon and aluminum bikes. I think several others have commented about the components being a crucial factor in how one feels about their ride.
    I have to say, my aluminum Felt crossbike that I use as my gravel ride, is considerably smoother than my Pinarello Dogma carbon road bike. Now a big part of that ‘smoothness’ is related to running 35 mm tires on the Felt. Tires make a huge difference in how a bike rides. Conversely, my Dogma is lighting quick and accelerates like a sports car. Totally different riding experience. On the road, I find the Felt cruises comfortably, but it’s not nearly as responsive as the carbon Dogma. I love both rides, but they’re very different. If I’m out on the Felt aluminum for 5 hours, no problem. But after 3 hours on the Dogma, I’m ready to get off. It generates a lot more road vibration and it’s a much less ‘comfortable’ ride.

    Brian on

  • I’ve worked for steel, aluminum and carbon tubing manufacturers over 30 years. I ‘ll go for an aluminum frame – lasts for years, doesn’t rust, doesn’t break and is just slightly heavier (10-20%) than carbon fiber frames. Save weight with simple structures – forks, handle bars, seat posts – are ideal for carbon fiber matrix/engineering.

    Richard George on

  • Carbon vs. Aluminum? Most bikes made out of either one Stink On Ice. There are good examples but I’m talking about the plethora of junk that is popped out of genetic molds or that is welded by robots. They are all either disposable dreck or complete arse-hatchets to ride…or both. Unless you are pinning on a race number and have a realistic chance of kissing a podium girl, get a steel or titanium frame and leave the ones made out of plastic and beer cans alone.

    Hoogle Da Boogle on

  • I have a 2004 Fuji Super light and a 2010 trek madone. I love both bikes and alternate riding 5 rides on one then 5 rides on the other. I have never had to adjust the gears on the fuji but have to adjust them on the trek every now and then. The fuji came with 9 speed ultegra gears and the trek has 10 speed ulterga gears. About 3 years ago I changed the fuji over to 10 speed Dura Ace gears and I still never have to adjust the gears. I love both bikes and they both ride super good.

    Roger Stewart on

  • There are way too many bikes in the world. Just get a bike that fits and have fun! There is a great youtube video of a guy that rode like 100k miles on a $100 bike. Quit feeding the system and start feeding love! You don’t need a new bike and it won’t make you happy but buying a bike for a child that really can’t afford it, thats awesome. Ask a neighbor or stranger if they want to ride to the park and make coffee, awesome! Save the planet, buy sell shit.

    Jacob J Meis on

  • Interesting article. As far as I am concerned carbon is over- hyped. I assume the profits are greater. I got a no name aluminum frame from Merlin for $175 with free shipping! Great riding internal cable very light. But ugly tho. Carbon cost too much! They have weird bottom bracket shells. Feels dead and wooden (this might be advantageous for some). Good steel is expensive. The best frame is 6/4 titanium but very expensive. If you find one that fits you try it. Try finding a used cannondale CAAD 12 for sale….people keep them! Now the CAAD 13 is only 980 grams! LESS than most carbon frames…carbon does soak up road buzz but I miss the road feel. 6/4 titanium is the best of all but unobtainable. Light stiff silky smooth very very lively. My custom Dean is ALIVE! I heard the same thing about the Colnago Oval Master Titanio.

    David Dudley on

  • GCN did a nice comparison on this subject. In the end it was determined that components were of greater value then frame material. Both evaluators agreed they would rather have a alloy frame with better components than a carbon with slightly less. I always liked racing aluminum. Just felt it was faster in a crit. Mountain biking is a different gig. Alloy frames are fun and you can bang them around, but speed comes with less weight.

    Richard on

  • Hey Igor,
    I wouldn’t worry about any carbon frame at your weight. Very few carbon frames have a suggested max weight, but even so, you’re still far lighter than what modern carbon bike frames can handle. The only real concern is wheels. The majority of wheels will be fine, but you’d probably want to avoid ultralight aftermarket wheels with low spoke counts. Pretty much any wheel that comes standard on a bike should be fine though. Hope that helps!

    Bruce Lin on

  • I weight 220lbs. Is a carbon frame right for me? Will it hold up?

    Igor on

  • Hey Kevin,

    Thanks for the question. It’s hard to know for sure what will help your wife without more details, but first things first, the frame material shouldn’t affect her feeling of stability. The biggest contributing factor to stability is geometry. If the Felt is a more traditional road racing style bike, with road racing geo, she simply might find the handling to be too “twitchy” for her preferences. I usually suggest riders seeking more stability and confidence descending to look at endurance road bikes and gravel bikes (which can be equipped with road tires). These bikes have more “relaxed” geometry that makes them feel more stable. 

    I did a write up on the subject here: https://www.theproscloset.com/blogs/news/why-you-should-ride-an-endurance-road-bike

    Hope that helps!

    Bruce Lin on

  • Appreciate the article. I went from a ten year old Scott aluminum ($1200 in 2011) to a new carbon Pinarello Razha ($2500 in 2021)…and the difference in ride was noticeable. The Pinarello seems to jump forward in comparison. I’m also using 28 tires. Very comfortable . Here’s my question: My wife is 5’2” and rides a women’s specific 48cm aluminum Felt. She gets a bit unstable going down steep hills, especially in wind. Would a carbon frame make a difference for her? Would she find it more stable?

    Kevin Clark on

  • The article sold me on carbon, but the comments just sold me on aluminum. Yes, I would LOVE the smoothest ride possible, but I simply am not going to take the extra precautions to prevent scratches on my bike.

    Michael on

  • In Scott Holmer’s comment on this article (two comments prior to this one that I’m writing) he mentioned that he would not ride aluminum on wet pavement if there are curves. Can someone explain this to me? Maybe elaborate a little? I don’t get the reasoning behind that. Clearly, I’m missing something. Thanks!

    David Archer on

  • I’ve really started to value your articles and happy to see them when researching a bike topic.
    I was leaning towards an aluminum bike buy you may have talked to me into a carbon one without trying. Anyway, nice article.

    Paul on

  • Carbon is so much more compliant, comfortable yet refined. There’s just something to leaning into a very fast curve and applying power on a carbon bike that you just don’t get with aluminum. If you just want a long ride anywhere, Carbon is so much more comfortable, posh, fast, responsive and controllable. It’s like having a BMW. Smooth, nice… fast!

    On the other hand there’s just something to throwing your bike in the back of your pickup truck with a couple of outdoor carpets on top then throwing your wife’s bike on top of yours, and then more outdoor carpet and your kids’ bikes on top of that then driving off to a destination. I’ve gotten our (mostly) steel and aluminum bikes that weren’t exactly new or in great shape scratched slightly here and there this way and it doesn’t matter. I’d never treat a carbon bike like that. My carbon bike stays home for long, fun rides always starting and ending from my house only. I would never transport it anywhere as the abrasion resistance is terrible. I was careful with it once but loading it on the bike rack with another bike leading to an OOPS moment costing me hundreds of dollars. Last time I ever loaded my carbon bike to go anywhere with it. Now it’s a “ride only from home” bike.

    That is why I own both.

    Attilio on

  • Good catch, thanks Carlos!

    Spencer Powlison on

  • I believe you meant to say at the start “comfort is completely subjective”.

    Carlos Reyes on

  • Test rode carbon specialized Tarmac (carbon) and Allez Sprint (alum). Bought the Allez and added carbon wheels (Roval C38). Even without wheels the Allez was alive compared to Tarmac, it was Fun To Ride.

    jeff lesueur on

  • Carbon is certainly a nice ride especially for the climbs but I’m not sold that it is the appropriate material for harsher riding like freeriding, or jumps where you risk a crash. I’ve seen carbon crack on mild impacts and requiring major professional repair or replacement where aluminum would have made it through with some superficial scratches and easily fixed with touch up paint. That’s an unfortunate reality and why there are now cottage industries of frame protectors and wraps designed for carbone frame bikes. The point about carbon being used in the highest levels of the sport…well many pros get their bikes for free or substantially discounted and don’t have to worry about breaking a frame because their sponsors will provide a back up bike. They often ride custom fabricated or prototype frames that are different from production models that you and I would find at our LBS. Not to mention that their sponsors have them ride what they want to sell to the public.

    Carbon is beautifully light but aluminum is far more abrasion resistant. That’s the key advantage when talking about strength between the two. Carbon might have a slight advantage in tensile strength, but aluminum has better abrasion and sharp impact resistance just through observation.

    Reyn on

  • I’m a woman in my 70’s , better than average fitness level, love riding my bike in a variety of conditions, pavement, dirt roads and gravel paths. My main considerations are fit for riding comfort, and weight for lifting and transporting to different locations.

    LInda Pero on

  • I have found that I can get an aluminum bike with better components, that feels more responsive at a better price. It feels noticably faster but also noodely. I won’t ride aluminum on wet pavement if there are curves, I keep a carbon bike for wet days. It’s all personal preference, but I look forward to riding my aluminum bike, where my carbon bike doesn’t really thrill me.

    Scott Holmer on

  • Great pro’s and con’s for both Carbon vs Aluminulm…in choosing a bike that is “right” for me, this truly gave me a better perspective than being taken to the bank by a bike shop wanting to only to make a sale. Thanks for sharing!

    Jerry on


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