DO I NEED A CARBON MOUNTAIN BIKE ? CARBON VS ALUMINIUM

Photo: Jim Buchanan

 

Despite the history of pains and imperfections in the early history of carbon bike components, quality, performance, and consistency have all been on the rise. There is no doubt that carbon frame and other carbon bike parts have a huge significance in a competitive mountain biking. But what does it mean for a non-competitive weekend rider like you and me ? Do I need a carbon mountain bike ? Before answering this question, let’s take a look at advantages and disadvantages of carbon vs aluminium.

 


 

CARBON MOUNTAIN BIKE VS ALUMINIUM MOUNTAIN BIKE

DO I NEED A CARBON MOUNTAIN BIKE ? CARBON MOUNTAIN BIKE VS ALUMINIUM MOUNTAIN BIKE

Weight

One of the most obvious and looked for advantages of carbon mountain bikes is their weight. It’s not a secret that it’s a lot easier to fashion a lighter frame from carbon than it is from aluminium.

Yes, you can buy a quality aluminium mountain bike that is lighter than many rigs made of the carbon. But well-made quality work will generally be lighter than most aluminium machines, although the weight difference can hardly justify the extra price.

The simple physics tells us here that less weight equals usually faster bike, especially on the uphills. The lighter bike is also easier to accelerate and change lines dynamically. That’s why cross-country riders will do just about anything to lose a couple of grams.

But is it always better ? The simple physics also say that heavier bike has more weight to push you down which in the presence of air resistance means that you go faster. Also, a too light bike can become skittish and hard to control in a rough terrain. It’s one of the reasons why you will still see many top competitive enduro and downhill riders on the alloy frames.
 


 

Stiffness

Quality carbon fibre offers 2 to 5 times more rigidity than aluminium and steel of the same weight. It has a significant meaning especially for cross-country racers where the weight and stiffness will result in razor sharp, ultra-responsive ride.

But the stiffer doesn’t always mean better even for competitive riders. Many enduro/trail and downhill riders chose alloy frames for their extra bit of flex and forgiveness which benefit their style of riding.

 


 

Strength and Durability

Carbon fibre vs aluminium strength ? It’s a tricky question. We still remember the early days where carbon mountain bikes cracked if you only looked at them wrong. And although carbon fibres frames still have a rep of ones that break easy, it rather comes to engineering rather than the material choice. This weakness is also often limited to super lightweight bikes designed for cross-country racing.

Carbon on its own is very brittle and prone to splitting and cracking. But by forming a composite material called epoxy resin, top companies can add crucial toughness and durability making carbon fibre frames incredibly strong. Today the tubing on enduro/trail mountain bikes is a lot thicker and much more resistant to impact while still being very light.

However, these two different materials have very different methods of failure. Carbon will crack and break, whereas aluminium will first dent then bend then break. “Absolute destruction of the element made of carbon fibre will follow suddenly and without any warning – unlike aluminium, which shows some warnings related to permanent bending.”

As much as any manufacturer wouldn’t recommend it, as long as it’s not bent, dented aluminium frame can still be ridden, while a snapped carbon frame is an expensive write-off in case your frame is not anymore under the warranty.

Another theory tells us that whereas carbon fibre frames will last indefinitely, aluminium will always have a shelf life due to the fact that this material does fatigue over time. Today, many companies offer a lifetime warranty on their alloy frames, which could mean that these concerns are long gone.

In practice, in serious MTB crashes and road racing pile-ups, you will often see a lot of broken carbon fibre. On the other hand, you will rarely see anything broken in aluminium. Perhaps in the real world aluminium really deserves a reputation of the stronger one.

 


 

Price

Despite the fact that carbon fibre is more affordable than ever, the cost still significantly exceeds mountain bikes made of aluminium. Especially when it comes to quality and quantity. It’s not just a frame we are talking about here. Bars, cranks, brake levers, brake pads, wheels, and even stem caps. There’s no shortage of them, and the price difference here will also depend on the bike part.

Mountain bike frames made of carbon are certainly more expensive than aluminium ones, but for example, carbon wheels can be almost 7 times more expensive than their alloy equivalents. Heat pressing, drilling, demolding, de-flashing, finishing, etc. Many hours of hand-made carbon rim will certainly cost more as opposed to minutes to form and weld an aluminium rim. Generally, carbon parts need a lot of hands-on work which makes them much more expensive.

 


 

DO I NEED A CARBON MOUNTAIN BIKE ?

There’s no doubt that carbon fibre frame and other components can improve riding performance. But what does it mean for a weekend trail rider ? Do you really need a carbon fibre mountain bike ?

Speed ? As much as it might feel like the weight of the bike is seriously slowing you down on these steep uphills, unless you are a competitive rider racing neck-and-neck, you will literally see no difference. You’ll make much better results by losing some weight of your body and improving fitness. Shoving off a couple of pounds of your bike is certainly not the most efficient way to chase speed.

The strength and stiffness are also very hard to be justified (especially if you ride enduro kind of trails) for a much higher price tag. Many high-end aluminium mountain bikes can easy outstrip low-end carbon ones even if the two weigh and are priced similarly.

In my opinion, not being a competitive rider you won’t gain anything by riding 2kg lighter bike. But, I guess if you have money to buy one and fix it when it breaks, it might be nice to have it.

 



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Showing 2 comments
  • S

    Seriously, that’s your whole article “But, I guess if you have money to buy one and fix it when it breaks, it might be nice to have it”???

    • admin

      What do you mean S ?

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