In the bicycle industry we are blessed with an array of variations across all frames, components, tires – you name it, but with this, comes a general understanding that is needed before making your next decision as to what to get.
One of the most prominent material alternatives you can have in the mountain bike industry is between aluminium and carbon fibre. Now, before we delve into this article, it needs to be said because it is often illuded to that because something is new and more expensive that is has to be better. Well, sometimes yes, but sometimes it’s just not what you are after.
The purpose of this article is to share a general understanding for what carbon and aluminium are, what the differences are between them and what this means for you on the trails.
The aim is that with a better understanding for what individual material is good for, you can make better decisions about how you want your bike to feel. Do you want it to feel more responsive? Do you want it to feel a bit for forgiving and have less feedback? Let’s take and look at the difference between carbon fibre and aluminium so!
Carbon fiber and aluminum are the materials often used in the cycling industry. Carbon fiber is a material with a high stiffness to weight ratio, making it a very applicable material for bicycles and components. It also makes it a more expensive option over aluminum, so there are some trade-offs to be made. In mountain biking, most riders will have a preference for certain components to be made from either aluminum or carbon. By combining the use these two materials on your bike, it creates a sort-of synergy, where they can work together to create a very unique feel on the bike. There are benefits to the carbon-aluminium combination that make it worthwhile spending that little bit extra to experience the use of carbon fiber on a bicycle.
Aluminium is a metal that comes from the ore bauxite. It is used in many products because it is strong, flexible, and inexpensive to produce. There are various ways to work with aluminium, such as machining, where a machine will remove the unwanted material to leave the desired form. Or, casting where the molten metal is poured into a mould and subjected to intense pressure to create the form that was left by the negative space within the mould. In all cases, the aluminium can then be painted, anodized or left with the raw aluminium look.
Carbon is a composite material made of carbon fibers woven together into a matrix with an epoxy resin bonding them together. The resin in carbon helps to strengthen the fibres and make them more resistant to fatigue when used in an application such as bicycle frames, handlebars, rims. Advances in carbon fiber technology allow designers to have more control over the stiffness and flex of the material during it’s use. The way a material flexes under loads is really crucial for how the ride will feel.
Both carbon fiber and aluminium are extensively used in mountain biking; however their properties make them ideal for specific jobs. For examples, let’s look at the use of carbon in wheels.
First things first. Carbon rims are not flimsy or easily destructible, the use of carbon in rims has been around for many years now and have developed hugely over time. If you are looking for a huge reduction in weight and an increase in the stiffness of your bike, rims is a very good place to start.
In addition to the price increase in price for carbon wheels, the actual feel of riding carbon rims is noticeably different. In mountain biking, we are always looking for grip and we help gain grip through the flex and movement of the rider and the components on the bike – the rims are no exception here. When we twist and turn, our rims are constantly tracking the ground and reacting to the movements of the bike. The flex in the wheel can be really important for the feedback the rider experiences. If a rim is super stiff, it doesn’t allow the wheel to track the ground as easily. However, stiffness often relates to efficiency and for a lot of riders efficiency is what they are after. Flex will naturally absorb energy, where a stiffer setup will transfer it. This can often mean that stiffer rims correlates with a rougher ride which is something to consider if you have very long days on the bike, but the rewards can be worth it. The bike is lighter, easier to get moving from slow speeds and easier to climb.
Aluminium rims will typically offer more flex, but are no means weak either. DT Swiss are one of the most prominent brands in the industry for reliable and trusted wheel sets on offer. Their spline product line offer a wide range of products at various price points. If you are looking for a more forgiving feel for when the bike is tracking the ground, through large compressions and quick changes of direction, aluminium wheels could be for you. With all these products, there is nothing better than to try them out on the trail as personal preference will always play a huge roll.
Another very noticeable change you can make to the responsiveness and feel of the bike is changing the handlebars. By testing between the use of carbon and aluminium handlebars you can get a real sense for the drastic change that reducing or increasing the flex in the handlebars can make.
Two very popular handlebars from Race Face are the Atlas (alu) and SixC (carbon) handlebars. With all bars, whether they are carbon or aluminium, you can cut the ends of the bar down to your desired width. Always important to remember though, you can always go narrower but you can never go back once you cut them down!
The main differences between the feel from a carbon bar compared to an aluminium bar are:
- Stiffer, more responsive to your inputs and feedback from the trail
- Lighter, removes weight from the front of the bike making it easier to lift the front wheel.
There is a balance to strike when it comes to stiffness on a bar. A handlebar that is too stiff can transmit very intense vibrations through the handlebar and into your hands. This is something that aluminium bars are very good at reducing as they reduce a substantial amount of it. If you are someone who is prone to fatigue in your arms and hands, a switch to an aluminium bar could be really beneficial. Similarly, if you feel you could benefit from a lighter and more responsive setup on the bike where fatigue isn’t an issue, a carbon bar could be change that may find you some added speed.
Advancements in material technology has completely changed the landscape for how we can utilise alternative materials to what we are conventionally used to – i.e metals. In the early days when carbon fibre first began to really make it’s way into the mtb industry, you most likely heard tales of how ‘people were cracking and breaking carbon fibre’, but times have changed. Not only is the material further optimised for mountain biking and other biking disciplines, so is the understanding for how you need to care for the material. Over-tightening on carbon fibre leads to damage and subsequent cracks. This is no fault of the designer but rather the mechanic/rider, with a lack of knowledge. The industry is far more educated now and is less of an issue as we come to understand how to better set up a bike.
Just because carbon fibre is lighter and stiffer (and typically more expensive), it doesn’t mean you need it. There are plenty of world cup riders still winning medals on aluminium frames and parts, it is just down to whatever makes you happiest to get from a to b!