Steel vs. Aluminum bicycle frames - ride quality, etc.

For those of you who are interested, here is some information regarding the difference between bicycle frames made of steel vs aluminum, that shound be, but isn't, common knowledge:

Over eighty six percent of the energy loss on any bicycle is from the flexing of the frame ("the overall loss of the pedaler's energy due to friction in the bearings is found to be less than 1 percent. Chain losses would add 1.5-5 percent". Source: 'Bicycling Science' 2nd ed.). This energy loss depends on the properties on the material used.

In the case of metals, it depends on the properties of them AFTER WELDING. No matter how good or how high tech the metal is, if it isn't welded good, it won't ride good. Two bikes made from the same tubing with the same design will steer the same, but one could be bumpy and hard to pedal and the other one could absorb bumps and be easy to pedal.
The difference is in the weld quality and resultant change in the properties of the metal.

We are mostly talking about steel here; all of our bikes are steel. Here's why:

Some steel bikes ride better that titainium ones, and vice versa; however the special facilities required for the cutting and welding of titainium ($$$$), its price ($$), and its availability (USAF) mean that we cannot use it and meet our goal of a killer handwelded steel bike ($) for the price of an aluminum production bike($).
Steel is a springy metal and aluminum is not (well, how many aluminum springs have you seen?). Aluminum bikes transmit high frequency vibrations (as do, to a lessor extent, poorly welded steel ones) while steel bikes absorb vibrations. The introduction of TIG (Tungsten Inert Gas) welding allowed a reduction of production costs for bikes, however the major impact was that use of an inert gas for welding allowed aluminum to be used for bike frames, despite its obvious deficiencies: transmission of vibration and a failure mode known as 'sudden and catastrophic.'

Economics rules the world. Bike tubing is cheap. Welders are expensive. Aluminum is weak, so a thicker tube must be used. A thicker tube allows the use of a less skilled welder (which is harder to make, a pancake or a crepe?), and this is where the very major cost savings occur.

Also, since thicker tubes are used in aluminum bikes, especially mountain bikes, the weight savings are not as much as one might think. This situation was put into very clear focus a few years ago when one of the bike companies we dealt with offered steel and aluminum mountain bikes at the same price. Our staff, and all customers who made a comparison, found that the steel bikes were a little easier to pedal and less bumpy, even if the steel bikes had no shock (this is because a shock is a low frequency filter but a high frequency pass,ie it does not do away with the undesirable properties of aluminum, just the gross features of the road surface-the 'jittery', high frequency bumps pass thtough the fork and frame to your hands).

...read the full guide with pics here

I own a steel road bike, but this article is still utter crap. There's so much to pick apart that I don't even know where to start. Maybe a ride on my "bumpy" aluminum full suspension mountain bike will jar my thoughts.

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I tend to agree with you. I own both and there is little difference in the ride that I can feel. I can feel a difference in the tire pressure though. The higher they are pumped up, the bumpier the ride gets. If you are looking for a new bike, test ride them both and get the one that gave you the best ride. It will save you from reading a very technical article that you may not understand.

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[QUOTE=kdelong]I tend to agree with you. I own both and there is little difference in the ride that I can feel. I can feel a difference in the tire pressure though. The higher they are pumped up, the bumpier the ride gets. If you are looking for a new bike, test ride them both and get the one that gave you the best ride. It will save you from reading a very technical article that you may not understand.[/QUOT]

+10. Utter bull****. Want a ride difference? Take some air out of the tires. I've had frames made from the big four materials, and the differences in ride were, at best, insignificant.

Energy losses in a frame? Very, very, very.......Did someone say very?........very, small.

The biggest difference between aluminum frames and steel frames? Aluminum has more letters than steel.

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Pain is Fun
I cut my fingers off
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Reading through this ****nut's--JimMayor--posts, he's just

__________________
Sex is horrid
Pain is Fun
I cut my fingers off
One by one

Reading through this ****nut's--JimMayor--posts, he's just SPAMing to push his Guides to Cycling Ignorance. As someone said earlier, there really is too much crap in his "guide" to address all at once. It's much better to just flush the **** away.

__________________
Sex is horrid
Pain is Fun
I cut my fingers off
One by one

Wow --- in the general classification of sheer rank stupidity, he's clearly doping.

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"All that we see and seem is but a dream, within a dream..."

Jim,
I thought your article was great and very informative. There are a lot of negavite people on this forum that just like to release anger so don't pay any attention to them.
Shane.

LOL, it's very full of information all right, wrong information. Anyone who reads an excerpt from the book Bicycling Science about bearing losses and then concludes that "over 86% of the energy lost on any bicycle is from flexing of the frame" clearly doesn't have the first clue about the physics of cycling. The book has a fine chapter on frame materials which contradicts most everything the OP states so strongly.

As to the "negavite people on this forum", sure people will be negative when someone posts blatant BS like it's some new knowledge he's just discovered. These off-repeated generalities about frame materials have been discussed and discredited many times over.

Ah, the blind following the blind! Don't cry when you fall into the gutter.

Is negavite anything like vegamite? I hope not, 'cuz I hear that vegamite tastes pretty damned bad.

__________________
Sex is horrid
Pain is Fun
I cut my fingers off
One by one

Older steel frames do ride sweeter! They usually have room for 27X1-1/4" tires!

No, Shane, you've got the wrong sample. There are a few people here who like to release anger, but what you've seen in this thread is the much larger group that don't take kindly to bull****. His article is the most staggeringly wrong summary that I have yet seen on this forum, and that is saying something.

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"All that we see and seem is but a dream, within a dream..."

I have the book Bicycling Science, and I will be honest, I haven't read it, only browsed a couple of sections, but I would be really surprised to discover if it even hints that 86% of the energy loss of cycling is frame flex. Especially since common knowledge is that the thing that robs the most energy in cycling is wind resistance.

If 86% of the energy loss of cycling was frame flex, the riders in the Tour de France would be riding bicycles with no flex whatsoever.

Instead, the bikes with the least flex are especially for those where acceleration is the key (the sprinters) and the bikes where sustained speed is the key (time trials) aerodynamics is stressed, and for climbing it is all about lower weight.

While it is true we don't want to ride bikes that flop around like wet noodles, there is no way that even 5% of the energy of cycling is expended to accomodate frame flex.

I regularly ride my steel framed bike & my 2 aluminium framed bikes(carbon forks on each).
Comfort, flex etc seems to me from my years of pedalling them to be about frame design, different wheels, tyre pressures, seats etc rather than just about the material the frames are made out of.
My 'race' bike is alloy framed & the harshest to ride but it also has the stiffist wheels, the shortest wheelbase and thickest tubing.