Bicycles can now be built with a wide variety of materials
including Chrome Molly (Cro-Mo) steel, aluminum, titanium, carbon fiber, and other
exotic materials. Which is the best frame material for building a bike
frame is an emotional debate in the
a big part missing in the debate is comparing
a cheap bike with an expensive bike. Cheap break and high quality do
There is a lot of debate and strong opinions in the
bicycle world about "what is the best frame". I believe that there are
minimum acceptable quality standards for frame material and workmanship.
In addition, specific frame types are designed for
specific applications. These issues are
fairly cut and dry with little disagreement. After these minimum
standards are met the "best" is abstract and involves unclear choices.
The different materials available for building bicycle frames is one of the most
of discussion anywhere touring cyclists gather. Building bikes frames with aluminum, steel, carbon fiber,
or other bicycle frame materials are all options. Each bicycle frame material has
its pros and cons but this is not completely agreed upon as well. I believe that the most important variable
usually left out of the debate is factoring in things like the riders size,
weight, strength, and preferences. The same frame will feel completely
different to everyone who rides it. A large, strong, heavy rider may
think a frame has to much energy robbing flex and feels "dead". A small, light rider may
think the same frame is too stiff and has a harsh ride. Even riders of the
same size and weight can have different opinions about how the same bike
feels when ridden. There is no frame material or design that is right
Test rides are seldom possible with the
majority of high end touring bikes sold in America/Canada because most
touring bikes and frames are not stocked by local bike shops. These choices have to be made
by looking at catalogs and manufacture's internet web sites. At first
there may seem to be a huge variety of touring bikes and frame choices but
once you boil it down to tubing, geometry, and construction techniques choices
are limited. The two main choices for touring bike frame material are aluminum or steel, with increasing
interest in titanium.
I (Tim) have never built a touring bicycle frame or any other
kind of bike. I am not a metal engeneer or metaloligist but I have
several decades of expierance, starting in the mid 1970's, and our current
international bicycle tour. This includes both steel touring bikes and
I grew up riding steel bikes before aluminan
bikes were known of but bought an alumin road bike in 1986 that I liked very
During our first two years of our around the world
bicycle tour we both used expensive steel touring bikes. After that we
switched to top of the line alumin bikes.
I like both and each has its advantages and sisadvantages
Seperating fact from fiction
Here is what I think
To narrow this discussion greatly I am only going to discuss
touring bicycles and leave road racing and mountain bikes out.
To further narrow the debate I am going to only talk about
steel and aluminan touring bicycles. I have never ridden a touring
bike made from titanium or carbon fiber. To my knowledge none exist.
I would love to try out a titinam touring bike if it had a real touring
geometry but I have never seen one. I am sure it is
just a matter of time.
Tubing diameter, wall
thickness, and reality
A bicycles ride quality is greatly determinend by its frame
charisticics. Tubing can have various diameters, lenghts, and wall
thickness. tube diameter
and wall thickness) and frame geometry
In theory the same ride quality can be achieved from any frame
material by changing the combination of tubing diameter, wall thickness ?
to stiff vs noodle
I have heard of alumin bikes getting repared in poor country
In reality there are not that many choices in touring frame
design so some generalizations must be considered. Cro-Mo steel touring
frames available are heavier, have more flex, and rust.
Alumin has to be built with larger diameter tubing
Conclusion = Even though any frame material can be made to
have a given ride quality touring bike frames are not available in a wide
spectrum of choices.
aluminen can dent due to thin walls and soft meatal
but a high price tag does no guarantee a good
bicycle either. Even an expensive frame can be heavy and have poor
ride qualities if it is built poorly or substandard materials.
I am speaking from experience because I have
made huge mistakes in this area.
During our first two years of our trip I had a
custom Cro-Mo steel frame made by a well known manufacture in the USA. It
cost a fortune and fit me well. I did not learn until it was too late that
although it was expensive it was made out of cheap straight gauge steel tubing
with no rust protection. This made it unnecessarily heavy, rust quickly,
and have a lot of flex. When I stood on steep climbs (the Andes has many)
my frame would flex to the point that the gears would shift on their own.
This flexing combined with the heaviness also gave the frame a "dead" feel which
was far from the lively responsive feel that I was hoping for. I could
actually feel and see my effort being absorbed by the rhythmic flexing of the
frame with every pedal stroke. I recommend that whatever brand of aluminum
or steel bicycle frame you buy
each and every tube and weld is
understood upon before buying.
All this being said the debate will no doubt
During our first two years of our around the world
bicycle tour we both used expensive steel touring bikes. After that we
switched to top of the line alumin bikes. Once the switch was made
public I recieved several emails from stonch supporters of the steel frame
camp that essentially called me a trader and promised to never look at our
site again. I believe that this is crazy. Something as nuatral
as a touring bike should not be turned into hardliner politics. I have
repeated this many tiimes on this web site "What is important in bicycle
touring is not the touring bikes. What is important is traveling and
meeting the people and cultures of the world."
I do not want readers to think that I am pushing alumum but rather want to
put the 2 material on equil ground. What you decide is best for you is a
personal decision. The recent trend among American touring cyclist is to
prefer steel while Europeans tend to prefer alumined.
The Frame Flex
Vs. Stiffness Misconception
Have you ever heard "an aluminan frame will beat you up
because it is too stiff" or "steel frames have a silky smooth ride because the
frame flexes and absorbs road shock? These statements get repeated often
in trendy bike magazines and web sites but does this make it true? NO, just
because we hear statements repeated regularly in popular media does not made it
scientific fact. It is best to look beyond the hype with independent
thinking. I have
always have believed that trueth is sometimes different than what is widely
believed. Alimun frames not being confortable or to harsh for touring is a
misconception. Sometimes I think that we consumers only know what the
marketers tell us.
We meet touring cyclist from all over the world on all kinds
of bikes. About half are riding aluminen framed touring bikes and the are
riding steel. Every now and then we also meet touring cyclist on a
titianem frame as well. They all seem happy with their frame material
choice. Each bike serves its rider well.
The misconception that some frame materials are more
confortable than others has been arounf for as long as alternative (to steel)
frames have been on the market. I have heard it from cyclist who have
never owned an alumin bike as well as people who ride both. Here is the
basis for this belief.
It is widely accepted that allumin frames are stiffer than
The logic applied here is
I do not know of any scientific test or reasearch so I have to rely on
Cindie and my personal expierances. We both have decades of riding both
steel and aluminum frame materials and, more recently, extensive expierance touring on both steel
and aluminan frames. Neither of us understand what all the fuss is about.
There is a difference in the way the different bikes feel when riden but both
are comfortable for long tours.
A stiffer frame has more pedaling efficiency
To make a steel frame as stiff as an alumin frame would
require it to be very heavey.
Standard Aluminum frames do tend to be stiffer. This is their
advantage because they are more efficient. Road vibration can be absorbed
in non pedaling robbing areas such as suspension saddles, fat tires stems, and
seat post. These road vibration accessories will make you float over the
road or trail without robbing energy.
After touring and traveling internationally for several years
I have determined that ihis misconception is a North American idea. The numerous Europeans I have met traveling on bicycles
have a much different opionen on the subject of touring bicycles.
Eoropeans believe that the frame should be as stiff and light
as possible. The road vibration can be absorbed through tires and
suspention saddles grips seatpost.
have told me that the big issue in Europe tends to be about 26 vs 700c or
streight bars vs drop bars.
It is a common argument that the flex that a steel frame gives
you is like a spring the redelivers your effort every pedal stroke. This
may be true to an extent but no spring will redeliver all of your effort.
If a spring could kids could bounce on a pogo stick forever. Certainly
some of the energy from your legs is lost forever every time the pedals go
around. This energy loss can easily be felt.
Cars and motorcycles have evolved to this idea decades ago.
You will never hear of a motor cycle that advertised a comfortable ride because
the frame flexes. Of course when you have a gas engine it is relatively
easy to build a frame that is beefy enough to have little or no flex while the
suspension system creates a silky ride.
The best way I have found to soften the road vibration of any
bike is to use wider or larger volumn tires
After larger tires I personnally like a brooks sping
stiff tracks better
Bike Frame Buying,
Building, Metallurgy and Tubing
Frame Builders | Best frame
material | Steel vs
Aluminum | Check for wear | Tubing manufacturers
Here are a couple sources of
information and commentaries on bicycle frame building and metallurgy
related to bicycle frame tubing.
Bicycle: Repair, Maintenance and Building. Several books pertaining to
designing and building bikes are included. Unfortunately most are not easy
(2) Frame builders list serve and
(3) What is the best material for
a bike frame?
There is no absolute answer. It
boils done to the engineering of the fame and the personal preference of the
user. By choosing different tubing (tube diameter and wall thickness) and
frame geometry, a skilled frame builder can make a soft or stiff frame out
of steel, aluminum or alloy. It is not so much a matter of the material, but
how it is used that determines the ride characteristics of a bicycle. It is
a mystery what determines every individual riders personal preference.For articles on choosing a material
search for "metallurgy" and "buying bikes" in the archives of the Adventure
Cycling magazine on their web site: http://www.adv-cycling.org/
. Many of these articles were written by John Schubert, Technical Editor,
Adventure Cyclist Magazine. Here is a sample of his insight, specifically
touring bike frames:
Out of steel, aluminum, titanium and carbon fiber frames, my favorites
are steel and aluminum, but intellectual honesty demands that I point out
that other well-informed people will have different preferences. My
reasoning: A good steel bike offers a great ride. Aluminum can be (and these
days it customarily is) designed to be lighter and stiffer than steel.
However, these properties (strength and stiffness) depend on the entire
bike design. The material selection is only the beginning.
Metal matrix allows some improvements in the bulk properties of aluminum
that mere alloying cannot achieve. It's on the order of magnitude of 10
percent improvement in stiffness and/or strength.
Some manufacturers have embraced metal matrix. Others haven't bothered,
saying it's not worth the bother to get that fairly small improvement over
aluminum (which basically has terrific bulk properties for bicycle frame
Since I at least try to speak with scientific rigor, and not throw out
slapshot opinions: Whether metal matrix in general, or "X" design in
particular, translates into an improved bike frame, and how that would
compare with other good bike frames of other materials, would be a good
topic for a master's thesis. However, no one who is interested has the
combination of time, money and skills to do the complex research required to
really answer the question.
You won't find any meaningful
published test data to compare different frames. The commercial magazines
have all descended into the "like wow dude" level of un-sophistication in
road tests, and aren't about to get serious. Adventure Cyclist has neither
the money nor the inclination to try. Manufacturers' literature is usually
skimpy and occasionally inaccurate, because their goal is to sell, not to
write a thesis."
I'm not as enthralled with titanium because it's an expensive way to get
a bike slightly lighter and not as stiff as an aluminum bike. And frankly, I
haven't kept up with the latest carbon fiber designs enough to have a well
Getting back to various steel
bikes, if all the frame dimensions were the same, the metallurgical
differences would be invisible to you as a rider. Every kind of steel
"feels" the same to the rider with two caveats:
Better steels are stronger (more
crashworthy), and hence they allow the bike designer to use thinner-wall
tubing to save weight. This also makes the bike less stiff. So yes, the most
expensive steel bike will not be as rigid as a lesser-priced steel bike.
However, the differences are minor.
A saying among people who write road test articles is "My favorite bike
is the one I just finished riding." Whatever the differences are, they're
small enough that one can fall in love with any of them.
Comfort differences among road frames are tiny, because every road frame
is a rigid truss structure that has very little "give" in the vertical
The best way for you to ensure your comfort is to get a bike that accepts
larger tires. The air volume of good-size tires absorbs far, far more road
shock than the tiny differences among frame materials. To get this kind of
bike, insist on a touring bike that will accept tires at least as large as
700x32C, or preferably 700x35C. If you get such a bike, you can always put
skinny tires on it -- in which case it will handle just about identically to
a racing bike (which couldn't accept the more comfortable touring tires).
Not all bike shops stock touring bikes, and some would be unwilling to
order them for you, but such bikes are made by Trek, Cannondale, Jamis,
Raleigh, Bianchi and numerous smaller companies. Don't let someone sell you
a "racing bike with three chainwheels," though -- such bikes, which are more
common in the bike business, can't accept the larger-diameter tires and
therefore won't have the comfort for touring."
(4) Steel vs. Aluminum for chopper bikes / art bikes: Chalo, a long time
custom bike builder and friend of IBF, gives the following advice:
For amateur chopper construction, steel is a much better material than
aluminum for several reasons.
Steel can be welded without significant loss of strength. Aluminum
requires expensive heat treatment to restore its strength after welding.
The equipment and inert gases required to weld aluminum are much more
expensive and elaborate than necessary for steel.
Steel can be brazed with brass, silver, nickel-copper, or other filler
alloys. Aluminum cannot be brazed in the conventional sense. There are
aluminum solders, but they are too weak to be useful for bicycles.
Steel can be drilled and bolted without unusual risk of cracks
propagating from the drilled holes. Aluminum will often generate cracks
starting at holes drilled in stress areas.
Steel can be formed (bent) to a greater degree before significant
strength is lost, compared to aluminum which only forms well in its annealed
(soft and weak) state.
When a chopper's design is insufficient to cope with the loads imposed
upon it, steel is more likely to bend rather than break off completely when
Add to all these reasons the much lower cost of steel bike frames and raw
materials of any given quality, and it's pretty easy to see that steel is a
better material for chopper building than aluminum in most circumstances. A
few exceptions to this general principle are as follows:
Parts machined from solid blocks are better made from aluminum, because
it is lighter and easier to cut.
When a commercial bike frame is to be used without modification, and when
the parts attached to it do not add unusual stresses above those expected
from normal use, then an aluminum frame may be used.
When very fat tubes and parts are desired which would be too heavy if
made from steel, aluminum may be used. The rule of thumb is that you should
use at least the same weight of aluminum that you would steel, about 3 times
more volume than a comparable steel part.
(5) Do frames fatigue, wear out and fail?
As you might imagine, frames vary tremendously. So many millions of
frames have been built, in so many thousands of designs, that some are going
to be more failure-prone than others.
To generalize, aluminum is fussier than steel. Aluminum has a finite
fatigue life; steel doesn't. That's what the textbooks say. But some steel
frames manage to crack too.
Similarly, titanium is supposed to be just about crack-proof, but there
are exceptions to that too. And carbon fiber's structural integrity depends
heavily on the quality of the design and workmanship.
An aluminum frame subject to repeated heavy loading (being bashed in hard
mountain bike use) may last a few years. At the other extreme, an aluminum
frame that is not stressed (ridden gently on the smooth road) may last for
At appropriate intervals all frames should be inspected from nose to toes
for small cracks. Small cracks grow; they never shrink. So when you see one,
take it to your dealer, who will probably tell you the frame is toast.
Cannondale Bicycle Corporation has posted a discussion of this topic in
their online Owner's Manuel, http://www.cannondale.com/Asset/iu_files/116376.pdf.
Go to section D, "Inspection for Safety" and take particular note of
"Fatigue 101," in Part II.
Gary Klein discusses some quality issues of aluminum frames starting on
page 5 of the PDF document at http://www.kleinjapan.com/at_klein/garys_speech.pdf
"Aluminum Time Bomb" in the May 1995 issue of Mountain Bike Action
magazine also address this issue.
(6) Bicycle tubing manufactures:
Columbus bicycle tubing
Dedacciai bicycle tubing
Reynolds bicycle tubing
See also the page on Bicycle Science, Engineering and Technology