time we have been working with the Columbus'
engineers, developing a new steel tubing for our
Countach and the Mondonico Futura Leggero frames. We
wanted to take these frames from being semi-pro to
full-pro without changing the price. It's always
easy to improve the specs of a bike: just make it
cost more. We wanted to make these frames much, much
finer without charging a single penny more.
First, a short
explanation: Torelli /Nemo 747 tubing is made by
Columbus out of Nivacrome, and drawn down to only
0.4mm, as thin as virtually any tubing in the world.
Frames made of tubing of this quality should (and do
when sold by other makers) cost twice what the
Torelli Countach and Mondonico Futura Leggero cost.
That's the short
story. Now for a fuller explanation so that, I hope,
you can appreciate what an extraordinary preformance
value frames made of Torelli/Nemo 747 represent.
In the 1970's and
1980's when Columbus' SL and SLX tubing were the
state of the art, the top tube was 25mm in diameter
and the downtube was 28mm in diameter. The tubing
wall was 0.9mm thick at the ends and drawn down to
0.6mm in the center of the tubes. This is what is
meant by "double butted". The internal
diameter of the tube varies so that the tube is
thicker at the joints, where the stress is greatest.
In the early
1990's, steel tubes underwent a small revolution.
The top tube changed from 25mm diameter to 28mm. The
down tube went from 28mm to 32mm. This increase in
diameter allowed the tubing makers to make the walls
thinner and still get a stiffer, lighter frame. An
additional bonus was the profound improvement in the
feel of the bike. The new bikes became more stable
(mostly, I think, because of the bigger top tube)
and gained a fluid, beautiful feel that is
impossible to describe, but wonderful to experience.
With these bigger
diameter tubes, the wall thickness at the thinnest
part of the tubes went from 0.6mm to 0.5mm and even
0.4mm. Columbus' Brain Oversize (or Brain OS) was
0.8mm at the butt and drawn down to 0.5mm in the
center section. People loved the feel of Brain OS
bikes, especially since the price was so reasonable.
But.... there was
something truly special waiting for those that
bought bikes made of EL-OS. EL-OS was 0.7mm at the
butt and drawn down to 0.4mm in the center section.
First of all, there was a reduction in weight, about
1/4 pound. That's always nice. The biggest bonus was
in how the bike felt. Anyone who has ridden an EL-OS
bike built by a good builder understands what a
supple, beautiful, wonderful bike really is.
The problem was
that getting a 0.4mm tubeset bike was expensive.
Even now, almost a decade later, there are tubing
companies that do not even have the technology to
draw a 0.4mm tube. Even though Columbus can now draw
0.385 (a reduction of 15 thousandths of a millimeter
from 0.4mm), I think we can safely say that 0.4mm is
still the state of the art.
Now you see why we
call our new tubing 747. It's 0.7mm at the butt, and
0.4mm in the center, and 0.7mm at the other end.
It's made of Nivacrome steel, the
super-sophisticated Columbus steel that loses very
little strength during brazing or welding.
Now, about the
butting. There are two ways that tubing is butted
(made thicker at the ends). One is the traditional
way, A in the diagram below. The tube gets
thinner symmetrically, with an even taper until it
reaches the new wall thickness. The other way,
called differential butting (B in the diagram
below), is the result of intensive study by
Columbus' engineers. They learned that there are
places in a joint that require a bit more thickness
than others. So, the precise shape of the butt
reflects that knowledge. The tube is only thicker
where it needs to be. Torelli/Nemo 747 tubing is
The chainstays of
Toreli/Nemo 747 are 0.7mm taper-guage. When we build
bigger frames, we build with 0.8mm chainstays.
When we were done
and satisfied with the tubing design, we asked
Columbus what we should call it. Being a custom
tubeset, it didn't fit in any specific tubing
category. They settled on Nemo, being a
differentially butted 0.4mm tubing. It differs from
other Nemo tubes in that Torelli/Nemo is 0.7mm at
the butt, and other Nemos are 0.65mm at the butt.
How does this fit
in with the other Columbus modern oversize steel
(0.8-0.5-0.8) is no longer in the Columbus
catalogue. However, they do draw it upon request for
some builders. For some very big frames, it can be
useful. It was replaced by....
In order to offer a tubing only 0.7mm at the butt,
Columbus developed a reduced price Nivacrome that is
1000 Newtons/square meter tensile strength. This
compares to the 900 used in Brain OS (and old SLX)
and 1200 used in EL-OS, Genius, and our Torelli/Nemo
(0.7-0.5-0.7). This is a very sophisticated tubing,
much finer that one would guess from the 0.5mm wall
thickness. Columbus pulled out almost all the stops
to make a lightweight 0.5mm tubing, using zone
butting, elliptical butting, the works. The result
is a tubing that is lightweight, yet very stiff.
Mondonico continues to offer frames made of Neuron
because it makes a good, stiff, light frame. This
tubing still has a very devoted following among
serious steel frame lovers.
(0.7-0.4-0.7). These sophisticated tubes are
comparable to Torelli/Nemo 747 in the front
triangle. They exceed Torelli/Nemo specification in
the rear triangle. These tubesets have double-butted
chainstays that are drawn down to 0.4mm. We were not
able to offer that in our tubeset and keep the price
as low as we wanted. EL-OS is no longer in the
Columbus catalogue, but Mondonico has it drawn for
his EL-OS monostay. The longer traditional butts of
EL-OS offer some performance advantages. The
slightly greater mass at the head tube joints make
the front end of the frame a bit more stable, or as
one Italian said, "robust".
You can see that
Torelli/Nemo 747 is a fine a tubing as any rider
might desire. For 2001, Torelli will use it in the
Countach OS frames, and Mondonico is going to build
the Futura Leggero with it. These are now full-pro
frames, that are superior to most frames available
at any price. Yet, they remain priced in the
I just weighed a
new 54 cm Torelli Countach TIG: a little less than 3
1/2 pounds. Why lose the beautiful resilience of
steel? At this weight and price you can have it all.