User Guide

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LEMOND TITANIUM
Titanium history in cycling
Titanium bikes have been around for
almost 30 years. During this tenure they
have earned a reputation for excellent ride
and durability. While the reputation of tita-
nium is generally well deserved, there is
more to a great bike frame than simply
the material its made from. The high cost
of titanium is wasted without purposeful
design and precision manufacturing.
Research and Development
Although Greg LeMond raced titanium
frames way back in ‘92, we wanted to take
a fresh look at the current titanium technol-
ogy. As a starting point we consulted Gary
Helfrich, the bike industry’s recognized tita-
nium guru. For those who don’t know Gary,
he was a founder of Merlin Cycles. Gary’s
experience with different tubing dimensions,
titanium alloys, and manufacturing tech-
niques were very illuminating. Our engineer-
ing staff followed these sessions with our
own extensive R&D. Armed with a clean
design slate and fresh research, it was time
to sit down at the computers and design a
titanium road bike worthy of the LeMond
label.
Which titanium?
There are many titanium alloys available
for bicycle manufacture. These different
alloys exhibit a wide range of mechanical
properties (strength, hardness, etc.) which
effect the final weight, stiffness, shock absor-
bency and overall ride of a bike. The physical
properties of the metal also determine
the available manufacturing techniques. The
right material choices were essential to our
ability to make a high quality, excellent rid-
ing titanium bike for a reasonable cost.
CP (Commercially Pure) titanium is avail-
able in a variety of grades listed numerically
as CP1, CP2, CP3, and CP4. These different
CP alloys are separated by the amount of
trace elements in the alloy, and they share
some of the physical properties of the more
popular titanium alloys. They are strong,
tough (resistant to crack propagation), and
resistant to oxidation. However, they are fair-
ly hard so they are somewhat difficult to
machine or cold work. In addition, CP alloys
do not have the tensile strength enjoyed by
some of the other titanium alloys.
3/2.5 titanium is an alloy with 3% alu-
minum and 2.5% vanadium. This alloy exhib-
its much greater tensile strength than CP
grades. With higher tensile strength, the
amount of material can be reduced while
retaining the same structural strength. Less
material means less weight. Another benefit
is that although its expensive to do so, 3/2.5
can be drawn or butted mechanically. This
allowed us to achieve the tubing designs
and manufacturing techniques our engineers
wanted to pursue. Plus, the thin wall sec-
tions enjoyed by butted tubing allowed us to
remove even more weight, while keeping the
joint areas thick and strong.
Another titanium alloy we use is 6/4 tita-
nium. 6/4 Ti has very high tensile strength,
and is less likely to form a molecular bond
(known as cold welding) when coupled with
different metals because its very stable on a
molecular level. These properties makes 6/4
ideal for fasteners like water bottle screws.
However, 6/4 exhibits extreme hardness mak-
ing it less than ideal for building a bike
frame. Machining, butting, or other metal
working with 6/4 is very difficult and expen-
sive. We use 6/4 Ti for the dropouts of the
Tete de Course where the strength is valued
on a thin structure. For tubes, the perfom-
rance of 3/2.5 Ti offers the same performance
without a weight penalty, and a much better
oost.
Butting titanium
A bike frame has much higher stress loads
near its joints than in the middle of the
tube. Some of the joints see much higher
loads than others, as exemplified by the extra
high stress at the head tube/ down tube junc-
tion. To supply adequate strength, these high
stress areas need a lot of material. However,
in areas like the middle of the top tube
there is much less stress. Where the stress
is lower the tubing can be much thinner and
thus lighter. To maximize strength and at the
same time minimize weight, the frame tubing
must have varying thickness, or butts (Fig.
T1). Butted bicycle tubing is an advantage
Fig. T1