Carbon fiber has become the material of choice for the majority of high-end bikes. It has replaced steel as the choice of pros, but one question many people ask themselves is, “can a carbon fiber frame last as long as a steel frame?”
When carbon started to come to prominence many years ago, lots of people were worried about its strength. Over time these worries have proven to be dumbfounded, and every year brings new advancements in technology that further enhance strength and lower weight. That is why even our lightest carbon fiber frames come with a 2-year warranty, longer than many warranties on metal framed bicycles.
The early carbon frames tended to self-destruct, which is one of the reasons that many people worried about carbon. But, as time has gone on and more money has been spent on carbon technology, things have improved and improved fast, and that is not just the perspective of frame manufacturers but also independent testers.
The one thing these tests have shown is that carbon fiber is more fatigue resistant than metal. You’ll find that titanium gives in before carbon fiber, and titanium is considered to be a lifetime frame.
So, what we are saying is perhaps, you should start to think about carbon as a lifetime material. The reason for this is because carbon fiber doesn’t behave in the same way as metal does. Metal tubes will be isotropic, and the material has the same properties in all directions. Carbon fiber is anisotropic, and it can have different properties in different directions.
One of the ways we can change how carbon fiber properties change is how we lay up the carbon fiber. When we lay up carbon fiber, it becomes a composite. It is a composite as it uses a mix of fiber and resin. The mix of these two substances can make a product that is tougher than concrete.
The correct way to mix fiber and resin is the main reason we have much stronger and stiffer frames now than we used to. Picking the correct resin for your cloth is one of the most important aspects of building a bike frame, and one that not many people talk about, probably as talking about glue doesn’t seem as cool.
If you pick the wrong resin, you’ll find that the resin doesn’t fully impregnate the cloth. THe lack of resin penetrating brings imperfections to the layup and can leave air bubbles trapped in the cloth and make it hard for the cloth to cure.
Carbon fiber frames have been susceptible to damage if they take a large force in a small area. It can lead to the frame being cracked, you’ll either need to fix this or replace it, similar to a metal frame. Many people have worried about this over time.
It is an understandable worry, but with mountain biking starting to wholeheartedly embrace carbon frames, we have seen technological solutions being devised to make carbon resistant to these knocks. Although the same as a metal frame if you have a big crash, it may not work out well for your frame.
Maybe it is time to weigh up these options and try and see where a highly fatigue resistant frame can take you.