Why you should consider aluminium for your next bike

Carbon fibre might get all the glory these days, but it’s not necessarily the king of all materials. You might think they’re a sign of a lower-end frame, but aluminium bikes can be fantastic. They’re stiff, light, fast and affordable – what’s not to like?

If you’re a die-hard carbon fibre fan, take note. Here are all the reasons why we think aluminium could be the right choice for your next bike.

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Ribble offer their CGR in carbon, aluminium, steel and titanium

It’s cheaper

The first - and maybe biggest - reason why you should choose aluminium. With aluminium, you can get almost all of the performance of a top-end carbon frame but for much less cash. And while the world’s best carbon frames are lighter, stiffer and more aerodynamic than the top-end aluminium ones, you’d be getting 90% of that performance on an aluminium frame, for about 20% of the price.

Those savings can be put straight into other parts of the bike: the wheels, the groupset – all things that will make a far bigger difference to how a bike rides than the frame material. Save on the frame, and allow yourself to splash out on the components.

Good aluminium is better than bad carbon

A really important thing to think about here is that while top-end aluminium is as good as top-end carbon, it can be far better than a low-grade carbon frame. Carbon fibre everything is an easy sell: it’s associated with loads of cool stuff like the Tour de France, Formula 1, fighter jets, and even space exploration. But not all carbon fibre is created equal.

There’s a massive difference between low-end carbon fibre bikes, and the bikes that win the Tour de France. The cheaper frames will have thicker walls on the tubes, lower-quality resins, and less stiff construction. That might sound pretty inconsequential, but even non-sprinters will be able to feel the difference.

So if you’re torn between a high-end aluminium bike and a low-end carbon one, you might be better off with the aluminium one.

Aluminium is more durable

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Aluminium can withstand crashes that would resign carbon frames to the scrap heap

Next up, durability. Carbon fibre is incredibly strong (as we found out in a recent test). In fact, it’s got a tensile strength about 3.8 times stronger than aluminium. But that strength is directional. If a carbon bike is impacted on the side of a tube, perhaps if you drop it, it doesn’t take much of a whack to crack.

Aluminium, however, can take plenty of knocks. It might dent, and it might get scratched up, but an aluminium frame is far less likely to properly break from an impact. And if you ask us, a few battle scars on a bike frame can look pretty cool

It’s because of this durability that we often see aluminium bikes between the legs of criterium racers. In these races, crashes are common, but where carbon can crack and splinter in a crash, aluminium will usually live to ride another day.

Aluminium is more precisely made

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Modern hydroforming is incredibly precise and repeatable

Quick quiz for you: which is manufactured with more precision, carbon frames or aluminium frames?

OK, we probably shouldn’t have put the answer to that one in that subheading, but still. It is a truth universally acknowledged that aluminium frames are made to a higher level of precision than their carbon fibre counterparts.

It’s because modern methods of forming aluminium shapes are highly controlled. Take the bottom bracket for example. This can be made from a single piece of aluminium, which is machined out to achieve the perfect shape and perfect alignment.

Manufacturing with carbon, on the other hand, is a process of layering and glueing. It’s tricky work, that takes a lot of time and effort, and is difficult to repeat in exactly the same way each time.

The weight difference isn't that significant

Bike weight: the eternal fixation of road cyclists worldwide. And yes, you’re right, aluminium bikes are a touch heavier – usually about 200 to 300g heavier than a carbon equivalent.

But let’s fire up the trusty GCN watt computer and put that number in context. Let’s imagine we’ve got a 75 kilogram rider and a 7.5 kilogram bike, and a 10km climb with 600m of elevation gain. To complete that climb in 33 minutes, the rider has to ride at… *beep boop beep* …304 watts.

If we then add 300 grams of additional system mass, for that rider to complete the same climb in the same time they only need to produce… *whirring computer noises* …1 to 1.5 watts more power. Really, unless you’re racing, that’s negligible.

Yes, that’s right, we’re saying it: bike weight is overrated. Raw power is what matters. So an aluminium frame really isn’t going to hold you back.

Aluminium budget affords better components

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Peter Sagan rode the Specialized Allez in the 2019 Tour Down Under Classic Criterium

Picture the scene. You’re in a bike shop, looking at two bikes. They’re the same model, and they’re the same price, but one’s aluminium and one’s carbon. How can this be? Well, chances are the aluminium frame will have higher quality components – one or maybe even two levels higher than the carbon one.

For example, where the aluminium bike might be equipped with Shimano Ultegra, the carbon bike might be equipped with 105, or even Tiagra. And those lower spec groupsets simply won’t shift or brake as well as the higher end ones.

And as you step down to those lower-end groupsets, your 300g frame weight advantage will be absorbed by those heavier components (not that weight matters, as we already said).

It’s not actually uncomfortable

Over the years, aluminium has got a bit of a bad reputation for being uncomfortable. Whilst steel and carbon flex under the rider’s weight, knocking bumps out of the road like a magic carpet, aluminium will shake your bones until your skeleton grinds itself into a small pile of dust… or so the theory goes.

But this perception was formed when aluminium bikes were brand new. Back in the 1990s, aluminium bikes were unforgiving, but a lot has changed since then.

Now, using hydroforming and butting, manufacturers can form aluminium into shapes that absorb road buzz. In fact, these days, the alloys themselves can be optimised for comfort. And perhaps more importantly, we all ride wider tyres these days, and at lower tyre pressures. Ultimately, that’s what really makes the difference to a bike’s ability to absorb road buzz.

So ignore this myth when browsing aluminium frames. All it takes is a slightly wider set of tyres to take any harshness out of a frame’s ride, no matter what it’s made from.

It’s better for bikepacking

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Bikepacking bag straps rub away paint and sometimes damage the frame material

You've probably heard of bikepacking. It's that thing that all the cool kids do where you pack a tent and head off into the sunset. We'd argue that, long term, aluminium is better for bikepacking.

It's all down to durability. Not only will an alloy frame hold up better if your bike takes some knocks, but it'll cope with the abrasion from bikepacking bags better. Bikepacking bags strap directly onto the frame, and over the course of a trip, the grit and grime that gets collected under these straps is going to rub away at your frame, damaging the paint and possibly even the carbon underneath.

If this happens on your aluminium frame, it might look a bit funny but it's not the end of the world – aluminium is far harder to grind away, so this abrasion isn’t likely to impact the structural integrity of the frame. This means that aluminium may well be the best choice for rugged outdoorsy types.

A material worth considering

As you can tell, we’re big fans of aluminium bike frames. But are we saying that aluminium is better than carbon? Well, not exactly. If you want the absolute pinnacle of bike engineering, and you have all the cash to spend on it, carbon is the way to go. Those top end frames are lighter, stiffer, and more aerodynamic. But if you’re on a smaller budget, or if you value durability over out-and-out performance, then aluminium is the material for you.

Oliver Bridgewood

GCN Tech Presenter

PhD Chemist turned cycling enthusiast, bringing the lab coat to GCN Does Science