when buying a new bike for many of us
that comes a point where we make the
leap to our first carbon frame the leap
that is often accompanied by a slight
scream as our credit cards wither away
to dust in our fingers yeah and we often
make that leap because carbon is
generally considered a better material
for frames than aluminium but is it
really how does a carbon bike feel out
on the open road in real life versus an
aluminium one we are going to find out
next to it here we have to trek in
Mondas they both got a full Shimano all
type of group set and they've both got
Bontrager finishing kit just as you'd
find in fact if you popped in to your
local trek dealer yeah they are almost
identical almost over because one is an
SL 6 may have tracks OC LV carbon fiber
and the other is an ALR six made up
alpha series aluminium we're going to go
take them up for a ride around our local
loop and then we're going to swap and
repeat who's going to ride what first
though rock paper scissors okay
we told you wanna ride first this one I
want to ride this one first
come on let's get me
you
let's start with that first one shall we
price and you are spending a lot of your
hard-earned money here so what's the
actual difference in this case is
between about eight hundred to a
thousand dollars or about seven hundred
pounds and that is for an identically
spec byte remember the difference in
price is due to the fact that carbon
manufacture is much more labor-intensive
and also more expensive generally though
I would imagine that when you walk into
your local bike shop you'll be looking
at two different bikes of similar prices
and so in that case your carbon frame
one is likely to have componentry at
least one or two levels below that of
its aluminium counterpart so
everything's getting a little bit
heavier and also you probably have a
lower grade of carbon fiber you might
otherwise want we haven't done that in
this case though because you want to be
able to directly compare how these two
different materials right
this is a really big subject when you're
chatting about things down at your local
bike shop carbon is more comfortable in
aluminium isn't it well actually this is
a really tricky subject and I was
talking to an engineer friend of mine
recently who specializes in this kind of
thing and he's done some analyses out on
the open road tried to come up with some
differences and failed he's basically
said it's almost impossible to quantify
differences in comfort between two
frames due to other things like your
tires how wide they are what pressure
you've got the map well how much flex
you've got in your saddle or your seat
post that's all well and good for him
but can we spot any differences but I've
been riding both bikes around about an
hour each so far with the tires exactly
the same pressure and I mean the same
pressure because we've been swapping
wheels between the two bikes at the
moment from my point of view the answer
that question is no yeah I think you can
ever so slightly carbon frame or good
carbon frame should I say has a very
slightly muted feel on the road in a
good way but I suppose the truth about
comfort and bikes is if you actually
want more of it you just need to put
wider tires on and drop the pressure
the next thing to talk about then is
stiffness which is really important for
power transfer so for things like
sprints or accelerating out the corners
ie responsive your bike feels but it's
also very important when it comes to
bike handling which is not talked about
quite so much so if your front end is
not very stiff it's going to make your
bike slightly harder to handle around
corners and over rough ground now
stiffness it can be measured in a lab
but what about the here-and-now
well I think it's more expensive carbon
frame is more responsive and when
pushing really hard and corners on rough
roads I think it's also more composed
but that is only in a direct comparison
and that is a really really important
point
yeah the differences are subtle enough
that you really only feel them in the
first five minutes immediately after
swapping bikes after that you notice the
difference is far less but the
difference is still there on the left
okay so this is the big one apart from
looks obviously apart from the looks
obviously let's put these two bikes on
the scales
so the carbon bike comes at seven point
five nine kilograms this aluminium one
comes in at seven point eight seven so a
difference of two hundred and eighty
grams not a huge surprise really given
that in general carbon frames that can
be made around about four hundred grams
lighter and it's acquitted an aluminium
one yeah but what do those weight
savings actually mean in the real world
then what on our little Tesla which is
about thirty grams as long with five
hundred meters of ascent this carbon
bike was 25 seconds faster and that's
broadly speaking with the same power
output doesn't sound like a lot does it
no and actually it's not really a lot
does I mean it's not significant
well that just depends as I said it is
faster that's a fact
whether or not that means it's
significant depends on you and what you
want to get out of your bike so let's
finish with the most important subject
of all which is of course looks now
modern aluminium frame sets are often
indistinguishable at a distance from
their carbon counterparts take the trek
alpha series and example the wording on
that frame is almost completely seamless
and the hydroformed tubes every bit as
graceful and beautiful and shapely
as any carbon frames them get up close
though and you can of course tell the
difference and if it is any confusion
just go do the tap test see are we
saying then that carbon frames aren't
worth the money no no we are not saying
that in pure performance terms Carbon
does have the edge is the difference
though as big as some people make it out
to be well no it's not especially if
you're comparing to cracking little
bikes from the same manufacturer
alright then tan here's a question mate
do you get an aluminium frame bike or a
carbon frame bike with cheap and
componentry I would go for the aluminium
with better componentry yeah I would as
well but in this instance with the same
component tree on an aluminium frame
will come frame I would go for
carbon frame yeah I think I would as
well we agree on both things
hey fist bump nice okay now if you want
to see a little bit more information
about the materials that we're talking
about here then if you click just up
there we've got a video about things
that you didn't know a carbon fiber and
conveniently up here five things that
you didn't know about aluminium make
sure you subscribe to GCN before going
to either those there to do that just
click on the globe