- Steel is the most traditional of bike materials,
it's got a long and distinguished career in cycling.
And while new wonder materials have stolen it's limelight
there are many people for whom a steel bike is
the dream bike but how does it really compare?
Well yeah steel is steel yes but there are many many
different types of steel because of course it's not an
element, it's an alloy of iron, of carbon
and a load of other elements added in to
make up the material that we see before us.
Now specifically 4130 steel, which is common known
in the bike industry as Cromo has the following alloying
agents added to it, with 95% of it of course still
being good old fashion iron.
Now it's not only the alloying additives that vary to
make different types of steel but also the way that
the steel is produced, specifically we're thinking
about different ways of heat treating.
Well yeah heavy yeah, top flight steel frame like this one
probably weighs about one and a half kilos,
where as top class aluminium could be 1,000ish grammes
and carbon fibre about 700 grammes.
And the fact is it's because steel is dense,
there is no getting away from that, it's twice as dense
as titanium, three times as dense as aluminium
and six times as dense as carbon fibre.
But clearly density doesn't tell the whole story
because otherwise our carbon fibre frame would be
six times lighter then our steel frame and it's not.
It's about twice as light, so obviously there are
other factors at play and what we're thinking about
then is tensile strength, fatigue strength, toughness
but right now we're gonna talk about stiffness or modulus
because funnily enough steel is twice as stiff as titanium
and three times as stiff as aluminium.
Which kind of gets us back onto an even keel.
The reason steel comes out heavier in the end then
is down to those other properties that ultimately govern
the size and wall thickness of the tubing.
You can use a little formula to work out the polar section
modulus, a phrase that you can now instantly forget,
but what it tells us is that fat tubes that are twice
the diameter of skinny tubes will be twice the weight
but they will also be eight times stiffer.
Now the problem with fat tubes is that they can be
prone to buckling, so to combat that you need to make
the walls thicker and there is the point at which
steel's density comes back to bite it in the ass.
Whereas aluminium tubes can be made fatter, stiffer,
thicker but also lighter.
So that is the reason why steel is a little bit heavier.
Does it really matter?
Well to the majority of us probably not actually no.
What steel advocates will often rave about and frankly
some of you do rave, sorry but it's true,
is the ride quality that you get with steel.
So that kind of ethereal unmeasurable description that
refers to the balance of stiffness, comfort and liveliness.
And the reason that that might be the case is that there is
an inherent springiness to a steel tube.
Columbus, who are one of the main manufacturers of
steel tubing refer to it as an elastic response.
Whatever way you want to call it it definitely differs
to the way that a carbon frame will kind of mute the
road buzz as opposed to bring it alive.
But I don't really want to get drawn down this path
because I don't think you can say that a carbon bike
does this and a steel bike does this because there is no
generalised carbon bike or steel bike.
What matters most is the engineering and it's here that
steel definitely has an ace card to play because it is
relatively easy to engineer
and it's also relatively inexpensive.
So that's why for many of us steel means custom.
This bike in front of me now from Saffron Frameworks
epitomises custom, not only is it made to measure
but each tube is chosen for it's specific properties.
And that is balanced against the demands of the rider,
so their weight, their riding style
and also what the bike is intended for.
Now I can't tell you how a custom bike rides because
I've never actually had a truly custom bike
but judging by the number of people that are over the moon
with their custom bikes and the whole buying experience
that goes with it, it's fair to say that for a certain
type of person there is definitely something in it.
Another strength of steel, at least traditionally at least,
is that you can repair it.
So if you were to have a monster crash at high speed
and write your frame off or indeed if you just fancied
modifying it and sticking a set of track drop outs
onto your old faithful and making it into a fixy,
both of those are options available to you.
But then we've also seen that actually you can do that
with carbon fibre as well, those frames can be repaired
and relatively inexpensively.
And indeed you could probably stick a set of track drop outs
on your carbon fibre frame if you were so inclined.
Added into the fact that some modern super high tech
steel tubes don't really like being re-exposed to heat,
so when they're being re-welded.
Actually this point isn't really as
clear cut as it used to be.
Yeah being fairest steel can rust but all you got to do
to prevent it externally is give the bike a good coat
of paint and internally a quick procedure once a year
will sort it out, you just got to whip the seat post out,
spray a frame saver inside and then that's it, job done.
And you add into that the new batch of super high tech
steels, which are also corrosion resistant at the same time,
which means you wouldn't ever have any problem with it
rusting internally, and externally you can leave
the steel exposed, which looks kind of nice.
If you were now hoping for an X is better then Y conclusion
to this video, then I'm sorry, but I am gonna disappoint you
because although steel doesn't quite hit the same numbers
that carbon fibre does it does have a whole stack of
plus points and many legions of fans.
It's fair to say that it is very much still a wonderful
material to build bikes out of.
Right that is the end of today's Maintenance Monday
video, do make sure you subscribe to GCN.
We have Maintenance Monday video every week.
And if you do it means you'll always be in the right place
but if you're in the mood for some more content right now
then hopefully either "Seven Things You Didn't Know About
"Carbon Fibre" or a similar video about aluminium
will hit the spot for you.
Check 'em out.