An opinionated discussion of Frame
Steel, Aluminum, Ti or Carbon?
Here is the basic thesis of this essay:
there are three forces that have recently and profoundly changed the
design of the road-racing bicycle
- The usual search for competitive
advantage on the race course.
- Marketing pressures.
- The manufacturer's search to reduce
costs, and the corollary desire to reduce the number of items
The result? Most people are being sold
bicycles that have had their ride quality seriously compromised in the
name of increased performance that is really illusory. To put it
bluntly, the bikes they are being sold ride like bloody hell. The
pleasure that can be had by riding a delicious, well-designed,
comfortable bike that is competitive at all but the very highest levels
of racing has been denied to the majority of the modern road bike
A discerning rider should look upon
lightweight road bikes as basically falling into two categories.
- All-out racing bikes (and
lower-priced clones that purport to be the same, but have none of
the competitive advantages and all of the disadvantages of these
bikes) that, while not offering the most comfortable or pleasurable
ride, give the serious athlete a chance to race without worrying
that his equipment will hold him back. Many items that claim to be
in this category are marketing tools aimed at the misinformed. But
more about this later.
- Riding bikes. An intelligently
designed bike will offer a wonderful ride, handle like a dream and
only slightly compromise the all-out need for the ultimately
competitive bike. I believe that these are the bikes most people
This all used to be so easy.
In 1975, a professional rider rode a bike
made of Columbus, or Reynolds 531. The usual group was Campagnolo Nuovo
Record, but a mixture of French or even Spanish components could be
used. The rims would be tubulars like Fiamme strung up with 36 spokes,
and have handmade (cold-treated) tubulars glued on. The bars were most
likely Cinelli, the chain and cogset Regina. The bike probably weighed
about 21.5 pounds. It was the state of the art. No bike could be made
that was faster, more reliable or significantly lighter.
At the same time, no bike could be had
that rode better than a handmade frame, built by a master out of 531 or
Columbus and assembled with the pro equipment of the day. The bike was
not only competitive at the highest levels of the sport, it rode
comfortably and had excellent vertical compliance so that it adhered to
the road. The sensual element that gives a bike ride its real pleasure
could find no better tool than the true pro bike of the '70s.
Bikes have changed. Those changes require
that a thoughtful person contemplating the purchase of a new bike to use
a different set of criteria than a rider of the '70s and '80s. It's no
longer enough to just want what the pros ride.
As I stated in my opening paragraph,
there are several forces at work changing the design of the professional
racing bike. First of all, the most easily noticed is the march to
lighter weight. This has caused the UCI (the governing body of worldwide
bike racing) to require that bikes weigh at least 6.8 kilograms (15
lbs.). There is a fear that the technological advance will obscure the
importance of the human effort in a bike race. The UCI wants to make
sure that the emphasis is on the athlete.
There are two other forces at work.
Manufacturers want to reduce the number of different items that they
manufacture. Sometimes this ends up being for the better. Threadless
forks are lighter, the stems are stiffer. The manufacturer gets to make
only one fork and cut it to length. Previously he had to make a
different threaded fork for each size frame. His life is simpler and the
bike is lighter and stiffer.
Compact frames reduce the number of frame
sizes that need to be manufactured. We make the Corsa Strada (not a
compact frame) in 18 sizes, each with a unique geometry. This many
items, all complex and differernt, are a manufacturer's nightmare, but a
bike rider's dream.
Fit and weight distribution on compact
frames, however, can be a problem. If a person is between frame sizes,
the choice between a too-short or too-long stem (and the same with the
seat post) will result in a poor fit and bad handling. The miniscule
weight savings does not make up for the disadvantages. But, the
manufacturer has saved a bundle. And you'll look like the pros in the
Tour de France who are being paid to sell this line of baloney.
Another force driving design is
advertising. Marketing costs are huge. In the sport-driven world of
bicycle advertising, these costs have ballooned. Up until the 1970s, a
big bicycle factory could, on its own, sponsor a high-end bicycle team.
Gone are the days of a Peugeot team stocked with Tour winning riders
like Thevenet. The last team sponsored primarily by a bicycle company
was TI-Raleigh. And this was possible because Tubing Investments, the
owner of Raleigh, amortised a lot of the costs of the team over other
branches of the conglomerate. Today, the bicycle supplier generally
plays a much smaller part in the financing of a pro team, which can cost
more than $8,000,000 a year. With these huge costs, the pro team has
been forced to become a more focused marketing driven device than in
decades past. Every square inch of the bike and the riders' clothing is
crammed with advertising.
In the past, rim manufacturers never paid
racing teams money to equip their bikes because the then-used
box-section rim is so anonymous. You never knew which teams were using
what rims. New wheels with deep section rims can carry obvious and
easily recognized advertising, but this is at a real cost to the rider.
The deep rims ride very harshly. The reduced spoke count wheel have very
high spoke tensions that exacerbate the problem.
The consumer is sold the wheels because
they are light. But, this is a half-truth. Because the rims have deep
sections, the inertial mass (rotating weight) is greater. The result is
that the bike has less snap and rides more harshly. To make it worse,
tests have shown that a rim needs to be 40 mm deep to have any real
aerodynamic advantage. The rims with their cross sections in the 30mm's
are not aero, they are only fancy looking. Before buying one of these
wheelsets that have lots of gee-whiz, consider a nice set of 32 hole,
cross-three wheels with box section rims. Put a pair on your bike and
give them a chance. Borrow a buddy's set if you have any. The weight is
almost the same. But the ride.........
On to the frames.
Bicycle frames and forks are made of four
different materials: steel, aluminum, titanium, and carbon fiber. There
other materials on the fringe, but they are beyond the scope of this
Steel, aluminum and titanium are metals
with an interesting relationship. Titanium has 1/2 the density of steel
and 1/2 the tensile strength. Aluminum has 1/3 the density and 1/3 the
strength of steel. Now the obvious conclusion that one can draw from
this is that a frame of aluminum should end up weighing the same as a
steel frame. A given cubic volume of aluminum weighs 1/3 as much as the
same volume of steel. But because it has 1/3 the strength, one would
need 3 times the material to make a given structure work.
It's not that simple. In building
bicycles, made of 9 tubes, there are problems in drawing the tubes too
thin in relation to their diameter. Given the current state of the art,
a bicycle downtube of steel is roughly 32 mm in diameter. It can be
drawn so that the walls are about 0.4mm thick. Any thinner and the tube
can buckle easily, and the tube is subject to denting as well.
Modern aluminum downtubes are usually
oval for greater resistence to bending under the normal load of
pedaling. The mechanical characteristics of aluminum are inferior to
steel. It will fail more quickly under repeated stress. So, the
diameters and wall thicknesses must be increased, but not as much as
would be called for to make up entirely for the reduced tensile strength
of aluminum. With a 42mm diameter, aluminum tubes can be drawn down to
0.7mm yielding a tube that weighs 185 grams, compared to 220 grams for a
state-of-the-art steel downtube. Multiplied throughout the bike's 9
tubes, it is obvious that a significant weight saving can be achieved
using non-ferrous (non-steel) materials. Intermediate weight savings can
be gained using titanium.
We know more about steel than any other
of the materials used to build bikes. It is one of the basic building
blocks of our civilization. Even though it has been over 150 years since
Henry Bessemer figured out how to produce steel commercially and
cheaply, new developments keep coming. In the early 1990s, Columbus
announced the introduction of Nivachrome steel. Previous steels used to
build bikes were chrome-moly alloys that lost as much as 40% of their
strength after brazing. Nivachrome was the first alloy specifically
developed for building bicycles. In the hands of a competent builder,
Nivachrome loses only 10% of its strength after building. Also, it is a
highly ductile steel (not brittle like glass) and has a very high
tensile strength. The results? Steel tubes could be made thinner and
Previously, because so much strength was
lost in brazing or welding, the tubing maker had to put a lot of
redundant material in the tubing to allow for the loss of strength. A
normal tube in 1976 was 0.9mm at the butted end and 0.6 in the center.
With Nivachrome, that changed to 0.7mm at the butt and 0.4 in the
center. This is a reduction of 1/3 of the mass of the tube with no loss
of strength or durability.
The resulting bikes made with these
modern 0.4mm thick tubes were light and had a new, beautiful, elastic,
delicious sensual feel that I cannot describe. I can only tell you that
it is there.
The other advantage of steel is
reliability. Modern metallurgy teaches that if a steel tube is bent and
released repeatedly, it will not break as long as the amount of this
bending remains within what engineers call the "elastic" range of the
metal. When a steel tube is bent until it permanently deforms, it is
said to have failed. As long as the frame is never bent beyond it's
elastic range, its life will be very long, indeed.
But let us not deceive ourselves. The
slight weight disadvantage that comes with a steel frame makes it
unusable for racing at the highest levels. A steel frame can be made
that weighs in the mid to low 3-pound range. Over a non-compact aluminum
frame, this is a penalty of about one pound. This is just too heavy to
chase Tyler Hamilton up a category-one climb. That is why the
professional peloton uses aluminum or carbon. But for the rider who does
not compete at the elite level, that one-pound penalty as part of a
whole rider/bike package that approaches 200 pounds (or may generously
exceed it) is insignificant. And for that pound, the rider gets a bike
that can take advantage of the high-tensile strength and springy
elasticity of modern steel and ride a bike that is an absolute dream. No
bike rides as well as a steel bike built by a skilled builder. People
who disagree with this conclusion usually have either a commercial
interest in other materials, or have not ridden modern steel bikes.
Forks. Putting on a full carbon fork will
save almost a pound. This is a huge weight savings in a single component
for a very modest price. I will save most of my comments for the carbon
discussion below. But, because the deformation of steel under load is
linear, the springy feel of a steel frame is greatly enhanced by the
lively feel of a steel fork.
The evolution of the aluminum
frame has been going at the speed of light. The first modern aluminum
frames that showed up in the mid 1970s by Alan of Italy used the same
diameters that were then used in making steel frames. The resulting
frames were very light, but they were so soft, I considered them
unrideable. Vitus also made aluminum frames that were very soft and very
light. I could say these were terrible bikes, but Sean Kelly beat the
rest of the world like gongs with these spongy imitations of real bikes.
There are many roads to the same place. One man's food is another man's
Then, builders started tig-welding
extra-large diameter alumunum tubes (Klein and Cannondale come to mind).
The resulting bikes were fantastically stiff, very light, but hard as
nails. I considered them terrible alternatives to good steel bikes
because they had gone too far the other way. The ride was just too
The engineers never stopped working on
solving the problems aluminum presented. Columbus came out with Altec
and the ride got better. Easton's offerings made frames that I finally
admitted were tolerable. Columbus' modern tubes Altec2 and Airplane make
fine riding bikes. I don't put their ride quality in the class of the
good steel bikes. But, if a rider is seeking competitive light weight
and acceptable ride quality, a non-compact, horizontal top-tube aluminum
bike will serve him well. The earlier problems of aluminum's tendency to
fail after only a short time has been basically solved. But the lifetime
of an aluminum frame is not and will not be that of a steel bike. The
rider has to accept that in his search for high-perfomance, compromises
must be made. These are not lifetime bikes. They just aren't!
This is the middle ground. Titanium is
not as strong as steel and it is not as light as aluminum. The result is
a frame that has a better ride than aluminum, but weighs more. It
doesn't ride as well as steel, but it is lighter. It is very reliable.
Titanium frame failures, like steel frame failures, are very rare.
Titanium also has another advantage. It doesn't rust. Riders in areas
where roads are salted like titanium frames. They don't have to be
painted. If the decals get wrecked, new ones are easy to apply.
I have good friends whose judgement I
respect who insist that this is the best material from which to build a
frame because of its middle ground between aluminum and steel. At this
point, it becomes a matter of taste.
I think it was about a decade ago that
Greg Lemond predicted that carbon fiber bikes were the future. I don't
think they have yet lived up to that promise, even with Lance
Armstrong's six Tour de France wins on carbon.
The first carbon frames I recall were
from Alan and Vitus. The aluminum tubes that were usually glued into
aluminum lugs were replaced with carbon tubes. Then, the next big
advance came from Kestrel with a monocoque frame. Lots of riders went
wild over them and adored the ride and lightness. Like all early
products, all of the above frames suffered from growing pains.
Reliability just wasn't there.
If we fast-forward to today, the advances
have been profound. The basic problem of carbon's reliability has been
solved. Millions of men and women trust carbon for the their forks, the
component on a bike that requires the greatest level of quality and
reliability. A broken fork can be catastrophic.
Producers of carbon fiber products have
advanced the basic technology of the raw material. Carbon fiber products
are made of carbon fiber imbedded in an epoxy resin. As the technology
has advanced, engineers have been able to reduce the amount of resin as
well as cabon fiber in the basic make-up of a carbon item.
This is important not only for a weight
savings, the basic reason people turn to carbon, but also for road feel.
I have a theory.
When the first carbon tubes frames from
Alan and Vitus showed up, they were slightly over size. They were still
quite soft as frames go. Then, when the first carbon fiber forks were
introduced, many of them mimicked the dimensions of steel forks. They
were terribly underdesgined. They were so soft that the front wheel
would vibrate back and forth in an unnerving shimmy when the front brake
was applied. These very soft, improperly designed items gave carbon a
reputation for softness. If an item were carbon, it was assumed that it
would give a soft, comfortable ride. It was not the carbon, which is an
extremely stiff material, that was causing the softness, it was the
Look at carbon forks today. They are
built to dimensions that are appropriate to the material. Carbon forks
are stiff, reliable and well-made.
So how does carbon fiber affect the ride
of the bike? Engineers can do almost anything they want with carbon.
It's all in how the sheets of woven carbon fiber are laid and epoxied
together. There is, however, a great deal of commonality in how all
carbon fiber products are designed for bicycles. So, we can paint with a
broad brush and make some general rules.
The epoxy in the carbon fiber matrix
damps high-frequency vibrations. If you have a nice road, it will take
out that road buzz and smooth it out.
However, because the deformation of
carbon under load is not linear, the worse the jolt or impact, the
harsher the feel. It can make a good road nice, but it will make a bad
road terrible as it bites back when the usual elastic limit of the
carbon is reached.
Some riders find the deadening of road
buzz delightful and pleasant. Other find that carbon fiber results in a
dead feel. Once again, it's a matter of taste.
I believe that the feel of the road is a
large part of the feedback I am looking for as I ride my bike. I am not
looking to isolate myself from my cycling environment. I want to be part
of it. For me, then, carbon works against my cycling goals. I have never
ridden a carbon frame or fork that gives the fine, pleasant, comfortable
ride under the widest set of condition that steel gives.
With changing technology, this judgment
is only for today.
So, what kind of bike to buy?
I still hold that a modern steel bike
built with hand-made cross-three wheels and good tires inflated to no
more than 110 psi remains the gold standard. No other bike will ride as
The elite racer looking for the lightest,
fastest bike is best served with a lighweight aluminum bike. He can get
good feel as well as high performance with aluminum. If he avoids
compact frames, he will get a finer ride at almost no weight gain. The
important, and now ignored, questions of fit and weight distribution are
better answered with a horizontal-top-tubed bike.
and read that steel road bikes have made a "comeback". COMEBACK?
We don’t think that they have really gone anywhere. Fans of
steel bikes have remained loyal. As recently as 20 years
ago, a professional rider feeding his family with his pedaling
talents rode a steel (cromoly) bicycle. End of story as far as
frame materials went. Steel was the gold standard. Since then,
many different materials have come onto the scene…some more
successfully than others. The general consensus remains to this
day that steel (cromoly) frames deliver the best overall ride.
Other materials might make a frame stiffer, lighter, more
aerodynamic, and in some cases some materials might make a frame
even MORE compliant and comfortable than steel tubes, but the
idea is still to make them all ride as close to steel as
Making a great
frame that rides incredibly well requires the balance of all
these characteristics (comfort, shock dampening, weight,
stability, traction, etc.). These attributes are all directly
related to one another. Making a frame lighter automatically
changes or "digs into" one of the other distinguishing
performance features. So all of these important riding aspects
must be considered carefully and be balanced. It seems that
steel frames keep this balance at a more favorable ratio than
any other frame material.
The number of
brands offering a full line of steel bikes is dwindling. This is
great news for Torelli and the Mondonicos, but a sad statement
of where the bike industry has gone in the last 20 years.
We know many
dedicated riders who have been riding aluminum or carbon for the
last few years and have decided to go back to steel, purely for
the quality of the ride and the experience that a steel bike
delivers. Frankly, a lot of them want a more comfortable bike
that doesn’t beat them up in certain riding situations. These
are men and women who have logged many miles on stiff, tight,
robotic frames for years and they are quite simply tired of the
lack of personality in their rigs. We mention durability and
longevity when speaking of steel frames. Aluminum and Carbon
frames have an effective "performance lifespan" that is much
shorter than steel. This means that the quality of the ride
deteriorates over time. It doesn’t refer to an all-out frame
failure. We think it is fair to say that a good steel frame,
built properly, can last 25 or 30 years if cared for. Aluminum
and carbon frames are much less predictable, but we think it is
reasonable to say that they won’t have the lifespan of a fine
This topic is best left for in store conversation, but let us
type a few words on the matter. First off, proof is in the
pudding: we've built full bikes with lugged, steel frames that
weigh in UNDER 17 pounds. And NO, they did not cost $6000.
Most of the steel bikes we build weigh in between 18 and 19
frames are the lightest available. There are some
exceptions, but if you want to talk about top-shelf, proven,
stage style frames, this remains accurate. Titanium is light no
doubt, but it has lost the label as the LIGHTEST bike material.
Carbon, in general, is light....but in some specific cases it is
NOT. When you consider ride quality, you can debate for
hours on weight vs. material. Ask us (in store) to explain
to you how some companies at the TOP of the food chain have
decided that Titanium and Carbon on their own don't make for
very good bike frames at all. The combination of these
materials is another story. More on this when you visit
Aluminum seems to
be the material that has come closest to the goal of doing what
steel does but with less weight. 20 years ago, aluminum
was lighter than steel but it was harsh riding and too stiff.
[There is a great story about an engineer from a BIG CORPORATE
BIKE COMPANY in the pits at the Tour De France in the early
1980's. A team competing in THE Tour was riding his
company's newest aluminum frame. When the riders returned
from the stage, they we assembled under a tent to meet with the
engineer for a feedback session. The engineer, through an
Italian speaking helper asked "How was the ride on our great new
frame"....the riders muttered to each other in Italian and their
collective reply came from the one team member that spoke a few
words in broken English, with a heavy twist of Italian accent..."It's
a-fast, but it's a-too a-hard!"]
As higher quality materials and aluminum alloys became
available, tubing manufacturers became more and more able to
make aluminum tubes with a thinner wall thickness which reduced
stiffness and even lowered weight more. BUT, at the same
time, steel tubing benefited from new alloys and advancements in
production and design. Steel tubing is now much lighter
than it had been. Also, frame parts like lugs, bottom bracket
shells, seat collars, etc. have been slimmed down by new
materials and production techniques to reduce full frame weight
even further. This lends some proof in our eyes that steel
is still at the forefront of frame material. If steel is
"OLD SKOOL" or "RETRO" or whatever you want to call it, contact
Columbus, Reynolds, True Temper or some of the other steel
tubing manufacturers and ask them why they continue to spend
millions of dollars on R&D for steel tubes!
what you lose in weight you gain in many other departments.
A light steel frame is 3 to 3.5 pounds*. A SUPER light
Aluminum frame is 2.5 pounds*. So we are talking about .5
to 1 pounds net difference. If your absolute 1st priority
is building as light a bike as possible, you won't choose steel.
If you want a very light bike that performs and rides to the
highest quality standard, you will love a steel frame.
WEIGHTS...not catalog weights or tech sheet weight!
and titanium are fine frame materials. After all the touting
we’ve done here about steel frames, you still might very well be
better off with another material. No worries, our friends at
Torelli and Mondonico all know this very well and all brands
offer frames made of these materials, and of course, all are
crafted in the Italian Style. If you aren’t sure what is best
for you, please consult with us. We can give you solid advice.
We will always throw the warning flag if we think a customer is
wandering down the wrong path when buying a bike or making a fit
decision. Ultimately, it is your choice, but we are here
to help you match your desires and needs with the right product.
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