aluminium is one of the most common
materials with which to build bikes
while the cheapest buy extends me steal
the most expensive a typically carbon
fiber the middle ground is occupied by
aluminium which to many people I guess
Masek seem particularly unexcited and
also gets a bad rap it's less
comfortable than steel it's not as light
as carbon it's less durable than
titanium but is it really well let's get
one thing straight first of all you
actually don't make bikes and aluminium
you make them out of aluminium alloys
and what those alloys are depends very
much on cost but also the
characteristics that you want the tubes
and therefore the frame ultimately to
have so for example Beaumont's cycles
who build frames exclusively out of
aluminium choose a 6000 series aluminium
for one frame because the
characteristics are slightly softer but
yet they choose 7000 series for another
because although stiffer and therefore
slightly harsher it is also more robust
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well that is good one firstly aluminium
alloys as a material are cheaper than
carbon fiber but it's mainly because
carbon frames take many many more staff
hours to produce than aluminium now it's
not necessarily skilled staff hours
whereas the brazing welding of metal
tubes takes considerable skill actually
carbon manufacturer is all about lots of
tedious labor but that labor needs
paying for and where as much of
aluminium manufacturer it can be
automated even if you cut the carbon
sheets by machine the rest of it needs
to be done by hand
now this is a definite myth nowadays at
least its origins are rooted in fact
mainly thanks to the second generation
of aluminium frames characterized by
those drop-dead gorgeous clients of the
early 90s with their massively oversized
and also very stiff tubes now the main
problem from that second generation of
frames came from the tubes which were
just that tubes meaning that their
properties were constant in any
direction unlike a carbon frame which
can be made stiffer laterally but yet
more compliant vertically however thanks
to considerable investment in aluminium
technology mainly in Asia new methods of
manufacture like hydroforming mean that
tube shapes can vary significantly along
their length and then when you add in an
advancement in our knowledge of butting
which is where tube thickness varies
along its length
meaning that parts of your bike might be
less than a millimeter thick and parts
of it might be considerably more what it
all means is that aluminium which is one
of its key natural traits is that it is
very soft is able to keep that yet still
providing a stiff platform to pedal and
steer from now this is a tough one to
answer as we saw in a previous video
about carbon fibre actually it comes
down to the engineering rather than
material choice when it comes to
robustness but as we also saw in that
video the two materials actually have
very different methods of failure so
whereas carbon will crack and then break
aluminium will dent and then Bend and
then break and any permutation of the
two could prove terminal but perhaps the
reputation and robustness does come with
good reason if you were to observe the
aftermath of a pileup in a road race you
would likely see lots of broken carbon
fiber but it's very rare that you'd see
anything broken in aluminium which means
there perhaps in the real world it
really does deserve that reputation but
another interesting point is that
actually whereas carbon fiber frames
will last indefinitely aluminium has
always had a shelf life put on it Owens
the Faton
Ariel does fatigue over time however
someone like Trek here actually offers a
lifetime warranty on its alloy frames
now meaning that presumably those
concerns are long gone well it does Anna
doesn't because you see where as steel
frames are famous for rusting there was
a common misconception that aluminium
doesn't corrode presumably because you
don't get those red telltale patches
under the paintwork but it does corrode
but instead of rust what you get is a
white powder typically where water has
got under the paint and caused it to
bubble up but again though that might be
a thing of the past because I contacted
Trek to ask him about it and they said
that the Alpha series aluminium doesn't
suffer from that problem and they've got
a raft of evidence both from in the lab
and out on the open road to back it up
so where as owners of older aluminium
may want to purely check to make sure
they don't have any telltale signs of
bubbling paintwork owners of modern
aluminium bikes can rest easy aluminium
alloys are consigned to the mid range of
bikes for economic reasons then but to
overlook it is a frame material it's to
do so at your peril because a high-end
aluminium bike could easily outstrip a
low-end carbon one on ride feel alone
even if the two are priced and weigh
similar amounts so it's perhaps for this
reason that big brands like Trek and
Canyon is still investing heavily in
high-performance aluminium as well as
smaller brands like Bowman what be
interesting then is to see how the two
materials stack up out on the open road
hmm what we're pondering that I did it
mention about that carbon fiber video
earlier on if you want to see it you
haven't yet already then you can click
straight through to it just up there or
to see behind the scenes at the saran
factory where we got to see not only
aluminium being machine but also carbon
being laid up click just down there for
that video otherwise make sure you
subscribe to GCN to do that just click
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