Steel bikes have an evergreen appeal and they remain the top choice for plenty of cyclists, particularly those of a more enthusiast bent who preoccupy themselves with notions of cycling purity.
I love a good steel bike as much as the next tedious man in his thirties, but I don’t think steel as a frame material deserves the almost mythical status it now enjoys. Let me explain why.
The case against steel
You want the lightest, stiffest bike possible? Don’t use steel. Mike Massaro / Cyclist
If you want a bike to be as light and stiff as possible and you prize these characteristics above all others, you should make it out of carbon. If you claim otherwise, you’re ignoring the facts.
The very lightest steel frames weigh more than even very average carbon ones, and steel bikes that manage to be very light only do so by virtue of being built up with expensive high-end components.
Steel is also a far less versatile material than carbon composite, because carbon is infinitely customisable in a way that steel simply can’t be. There’s no limit to the number of ways you can lay up sheets of carbon to target stiffness, strength and flexibility where you want it. You can also make pretty much any shape you want, a critical consideration when it comes to aerodynamics.
By contrast, a steel frame is inherently more compromised. Yes, you can select specific grades of steel for different tubes that have different fundamental properties, and yes you can do some very clever things to influence the material’s behaviour ranging from exactly how you treat the metal during production, to butting and all manner of manipulation into different forms. However these methods all need to work within the limitations of the material.
Put steel under a microscope and you might be surprised what you see. Djhé via Wikimedia Commons. Licensed under Creative Commons
At the microscopic level, steel’s behaviour is determined by the crystalline arrangement called its grain structure. Manufacturing methods work with the grain structure to produce finished products with the desired characteristics.
Think of it like wood – you wouldn’t make a table leg with the grain running crossways because it would be incredibly weak, with little ability to withstand shearing forces such as someone dragging the table across the floor. (You’d also need to start with a very wide tree, but that’s an unhelpful aside.)
Grain structure is one reason steel products are often bent, forged or drawn rather than simply machined from solid blocks. These processes preserve grain structure and align it to the form of the finished piece, distributing stresses more evenly.
Machining, on the other hand, cuts through the grain structure. As a result, if you compare two outwardly similar metal components (eg brake levers) where one is forged and one is machined, the forged one is likely to be stronger and less likely to have stress risers – points where stress is concentrated that can increase the chance of failure over time.
In reality, many components are made using a combination of processes. For example, the overall shape might be produced by forging, but finer detailing added by CNC machining.
My point here is that for all of steel’s wonderful qualities, a framebuilder is limited in what they can do with it because its fundamental structure can’t be changed at the point tubes are being turned into a bicycle. And at the macro level there’s only so much you can manipulate a tube – you can’t have any form that you please.
There are literally infinite ways to lay up carbon. George Marshall / Cyclist
Composites place more power in the hands of the manufacturer because the act of laying up carbon is analogous to being able to determine the desired microstructure of steel and arrange it differently to suit different areas of the frame.
As well as being able to choose different grades, weaves and types of carbon sheets to suit their needs, carbon frame manufacturers can specify the orientation of every piece during the layup process.
I do not hate steel bikes
I actually really like steel, I’m just realistic about its properties. Joseph Branston / Cyclist
Does it sound like I don’t like steel? You couldn’t be more wrong, and I have two steel bikes in my garage right now – a fixie and the do-everything winter all-roader pictured above (look out for a What We Ride feature on this soon). Everything above is essentially an academic argument that ignores real-world considerations.
Ultimately what matters to me is the actual experience of riding a bike and what it’s like to live with.
Steel bikes can be wonderful to ride and aesthetically beautiful, and the material does have some advantages over the alternatives for specific use cases.
It’s relatively cheap and the tube sets favoured for bikes generally produce frames that are robust and well-suited to the rough and tumble of everyday use or off-road riding, eg, for gravel.
Even editor Pete can build a steel bike, with a little help. Adam Gasson / Cyclist
While it’s hard to get good data for this, I’d also hazard a guess that steel is a good bit more sustainable than carbon, partly because steel frames are highly repairable.
Carbon frames are often treated as somewhat disposable, although this is as much to do with changing fashions as anything else, as damaged carbon can very often be repaired too with appropriate specialist intervention.
So what’s your beef?
Steel can be stunningly pretty, but it isn’t magic. Mike Massaro / Cyclist
I object to people ascribing magical properties to steel. Our affection for the material is inextricably linked to our collective fetish for all things retro, and as a result we’re not always clear-eyed in our assessment of why we prefer one bike over another.
You can tell when someone’s writing about steel – and I’ve been one of the offenders here – because they’ll trot out adjectives like ‘classy’ and ‘timeless’ while perhaps lauding ‘springy’ or ‘smooth’ ride quality.
On the latter point, there’s good data to suggest that steel frames aren’t any more compliant than aluminium or carbon ones. Alee Denham of Cycling About looked at this topic back in 2020 and highlighted studies showing that vertical frame deflection – often taken to be a direct corollary to comfort – hardly varies between different materials because the frame contributes so little flex to the total package compared to other elements such as the tyres and seatpost.
Many steel bikes adopt traditional geometry with a near-horizontal top tube meaning there’s not much seatpost on show, and as a result it’s entirely likely they’ll be less comfortable than comparable aluminium and carbon designs.
Of course ride feel is about more than simple deflection. Vibration damping is a significant factor (carbon composites tend to be good at this…) but some people simply prefer the way steel rides. That’s fine.
This is not your average oven. Fred MacGregor / Cyclist
Steel is also intrinsically linked to notions of artisanal authenticity. It’s the OG frame material and unsurprisingly the one favoured by most custom builders, because you can build steel frames with some relatively simple and affordable equipment. The same is not true of carbon, which typically requires expensive industrial machinery such as specialist ovens (unless you’re Sideways).
So let’s be clear: steel is pretty, practical and can be made into great bikes. It is not however the most highly optimisable material, nor the best choice if absolute performance (ie, the best possible stiffness-to-weight ratio) is the priority.
Steel is real, but it isn’t magic.
Looking for more hot takes? Read why Sam thinks gravel bikes definitely don’t need suspension