This article will help you make a good decision on whether to buy carbon frame.
The main content of the article:
- How is a carbon frame made?
- Not all carbon is made equal
- Properties of a carbon frame
- How Long will a carbon frame last
- How much is the carbon frame
- Technology and design
For many of us we come to a certain point in our life where we need to make some difficult choices: new bike day. There is so much to consider while looking for your new bike, but one of the first questions that pops in any riders mind is: an aluminum or carbon frame? Certainly we’re lured in by this amazing stuff that’s known to us from Formula 1 or even from aviation. And many of us will make the leap from an aluminum to their first carbon frame. Generally speaking, carbon is considered the better material for frames than aluminum. But what makes it better and is carbon always the correct answer for your ride?
How is a carbon frame made?
To put it simply and easy to understand a frame is made from weaving carbon fiber strands in certain patterns and then setting within a hard epoxy resin which is then shaped into bike frames using molds and heat. Manufacturers use a number of different techniques. For example some high-end carbon bikes use modified monocoque construction. means that the head tube, downtube, top tube, and seat tube consist of one continuous piece.
carbon bike frames are very light, strong and reasonably stiff. The material is also easy to craft into aerodynamic shapes, and it allows engineers to play with variable strength or flex in crucial areas around the bike. This is mainly why carbon is used for the best bikes in the world because, right now it is the most highly optimizable material we have at our disposition.
Not all carbon is made equal
Just because a bike uses a carbon frame does not mean it’s as good as bikes that are optimized and use quality carbon. In fact, low-end carbon frames have some undesirable characteristics and you could be better off with an aluminum frame. Matter of fact, a low-end carbon frame could weigh even more than a high-end aluminum frame, certainly depending on the components fitted on both bikes
There are a lot of different ways that carbon frames are built as well as the way the carbon fiber itself is made. For example, the used type of resin, the thickness of the layers, the construction style, the way the material is heated, the direction of the fibers, the grade of carbon fiber, the density and types of fibers used all play a role in the durability, stiffness, ride characteristics and comfort of the finished frame.
Properties of a carbon frame
Lighter
The first thing that comes to mind when hearing the words “carbon frame” is weight, as a lighter bike let’s you climb and accelerate faster and maneuver more easily. When looking for the lightest bike possible your best option is a well-made carbon frame. A top road bike frame can weigh as little as 700 – 1000 gr while a top of the line aluminum frame can weigh 500 gr more. Although for most of us it would be easier and cheaper to lose the extra 500gr on our body than buying an expensive lightweight bike.
Comfort
Carbon transfers less vibration and shock through the bike than aluminum, carbon does a better job of absorbing shocks and dampening vibrations from the road. Certainly on road bikes you’ll feel a big difference between a carbon fork and an aluminum fork.
Generally, you want your frame to be stiff laterally so you don’t waste energy flexing the frame from side to side as you push down on the pedals. Vertically, you want some flexibility for shock and vibration absorption. This makes the ride more comfortable while riding over bumps or rough roads.
Stiffness vs flex, it’s a difficult exercise for bike manufacturers, which some still don’t get right. The bottom line is that the flex-stiffness balance is an art. Getting the right feel on the bike, what is to stiff or to flexy, is a matter of experience. Like any great artist, bike manufacturers need to learn and perfect their art before you can enjoy it.
For example, high-stress areas, like the bottom bracket, can be made incredibly stiff. Other areas, like the seat stays, can be made more compliant and flexible. This creates a comfortable frame without sacrificing efficiency or responsiveness. The lower density of carbon fiber also helps with vibration absorption. The improved ride quality is more noticeable on road frames than mountain bike frames.
How Long will a carbon frame Last? And can it be repaired?
Theoretically, a carbon frame lasts longer because carbon fiber doesn’t fatigue like aluminum. A carbon frame can last indefinitely, as long as it’s taken good care of. This means using a torque wrench to spec every bolt up to torque, not clamping your frame too hard on your bike stand and of course, don’t try to crash your bike.
Although carbon fiber is an extremely strong material, it is more brittle than aluminum. It can’t handle as hard of impacts without cracking. If you participate in a cycling discipline that is particularly demanding on frames, there is a good chance that your carbon frame will crack during an accident and fail prematurely. But one of the benefits of carbon frames that it can be repaired in most cases. Most cracks and damaged sections can be repaired but it’s a job you better leave to a professional.
Aluminum, on the other hand, fatigues over time. Aluminum will eventually crack and fail. How long your aluminum frame lasts depends on a couple of things: the type of riding you do, how you treat it, the quality of the aluminum and welds. It may fail after 5 years, if you’re harsh on your frame but if you treat it properly, you could get decades of use out of it.
Any good manufacturer guarantees their frames for a certain amount of time. If you crack your frame, you may be able to get it replaced for free. Be sure to check your warranty before going out and buying a new frame.
Carbon Frame Cost
It is no secret that carbon frames are more expensive than an aluminum frame. The main reason is the production cost. While aluminum frames can be mass-produced and automated a carbon frame is a more labor intensive process and the raw material is more expensive.
Most of the work is done by hand instead of a machine which leads to more man hours and higher labor costs. And manufacturers need to invest in a lot of specialized equipment, like molds and ovens, that all adds to the costs.
Technology and design
Since carbon frames are laid up by hand framebuilders and engineers can finetune their creation with limitless options, optimizing everything to their desires.
For example the direction in which the carbon fiber is laid or changing thickness by adding or removing layers, a different type of resin is used… The options are limitless to change a bikes characteristics.
This is why carbon is considered to be higher end and why almost all professional racers choose a carbon frame.
Final thoughts
Your choice between a carbon fiber or aluminum bike frame, will mostly come down to weight, durability, comfort, and price. There are tradeoffs between these four and it all depends on the priorities you set when choosing a new bike.
If weight and comfort is more important over durability and price you’ll want a carbon frame. But also consider how often you crash, your style of riding and your budget and is weight really that important to you? In the end you’ll have to compromise somewhere.
