In order to appeal to a wider audience many manufacturers like Giant, Norco and now Ibis offer their bikes in both a carbon and an alloy frame option. The carbon models naturally cost more so what makes them better or should we save ourselves some money and go for the alloy option?
Weight is an obvious place to start when comparing the two. A well made alloy frame can weigh in at a very respectable weight and come within a few hundred grams of their carbon brothers while other lesser quality aluminium makes will be heavier again. A lighter bike will be easier to manoeuvre and more friendly on the climbs. A few hundred grams may not seem like much but it can be hard to save this kind of weight in one area on your bike and the cost of changing multiple parts over quickly adds up.
Even though the bike may have the exact same geometry and suspension the actual feel whilst riding the bike can vary between carbon and alloy frames. Designers of carbon frames can manipulate the fibres of the frame to handle vibrations in a way that will benefit riders. Getting on a carbon frame doesn't mean you're getting on a magic carpet of smoothness but riders in tune with their setup will notice that trail chatter is reduced. Not all riders will be able to feel the difference and poor execution of carbon frames can actually make for a rougher ride. It's important to go for reputable brands like Giant, Norco, Santa Cruz, Forbidden, Yeti, etc. when choosing your carbon frame to experience the best handling characteristics.
Now we just told you how good carbon can be at handling vibrations so it's got to be a bit of a soft noodle right? Wrong. Carbon frames can be made with great levels of stiffness, in fact some early carbon frames were too stiff causing greater rider fatigue and poor handling. But, carbon designs have come a long way and with the right design the frame will be stiff in the right places enabling you to snap out of corners with speed and precision. A well designed alloy frame may not have the same stiffness or require a bit more material and therefore weight to achieve it but can be well stiff enough to provide fast and accurate handling as well.
Firstly we need to understand that bikes are really strong but aren't indestructible. When bottomed out there can easily be over a tonne of force going through a frame that weighs close to 2kg. In both carbon and aluminium it's seriously impressive what bikes can handle. The big difference is in the unlikely event of a failure aluminium can deform; bending or denting before braking where as carbon will crack. Giant offer a lifetime warranty on both alloy and carbon frames showing their firm belief in the durability and quality of both materials. We'd always recommend you buy from a quality brand that has a clear warranty policy so you know you're looked after in the event of an unexpected failure.
What's Best For You?
If you're after the best of the best carbon is the answer but understandably not all of this have that luxury. When you're comparing two bikes of equal value an alloy model will likely have better components so if you're not one to fuss around with changing parts over this may be more suitable. On the contrary, if you're likely to tinker and upgrade parts as time goes on you'll get greater benefit out of having that carbon chassis as your base.
If you're looking for your next mountain bike check out our offerings here or better yet, come into our Brisbane MTB store and talk bikes with our friendly sales staff.