British adventurer Maria Leijerstam achieves world first by cycling to South Pole

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12. Chrome Moly wins again

Chrome Moly Steel was the best material for bicycles by far from the 1930s till the 1980s. Cannondale figure out a way to make an Aluminum frame that could be repaired if broken (and most breaks occurred in the area where the rear wheel is attached to the frame). Titanium followed in the 1990s and today the push is fro Carbon Fiber.

Side note: Cannondale success with aluminum was the design of a frame without the rear four inches (the rear drop out). Cannondale then, using precision tools, slide an aluminum rear drop out into the frame and paint over it. The parts are NOT welded but held by glue and friction. Thus if the rear drop out breaks, it can be replaced without replacing the whole frame (Which is what you have to do if any part of a solid aluminum frame breaks).

Chrome Moly big advantage over the later frames is that it can be repaired. Now, high tension steel bike frames (High Tension Steel the wonder material of the 1880s, had the Titanic been built with it, it would have survived the ice berg) if broke can be repaired by anyone with a welding torch. Chrome Moly requires brazing, a more complex operation then welding, but can be done locally (Through over the last 30-40 years TIG welding has been used on Chrome Moly Frames with great success).

http://news.thomasnet.com/IMT/2005/01/18/welding_vs_braz/
http://en.wikipedia.org/wiki/Brazing
http://www.carbideprocessors.com/pages/brazing-carbide/brazing-and-welding-important-differences.html

The other three materials, Aluminum, Titanium and Carbon Fiber, if the frame breaks it has to be sent back to the factory (and generally trashed). Chrome Moly Frames can be repaired.

Furthermore, Chrome Moly Steel tend NOT to have Fatigue Stress Cracks, a Characteristic of the other three material. Now, Chrome Moly Steel Frames can break do to Stress, but it is predictable i.e, after X number of hits it will break. The same can NOT be said of the other three materials. This is Chrome Moly's greatest Strength, at just a slight loss of power through the frame (when compared to Aluminum, Titanium and Carbon Fiber) you get a much more durable frame.

Side note: The big ease in peddling that comes with higher end bikes is the switch from High Tension Steel to Chrome Moly Steel Frame. The difference between Chrome Moly and the other three is real, but very marginal. If we were to put them on a scale, High Tension steel would be a 5, Chrome Moly a 9. Aluminum a 9.5, Titanium a 9.6 and Carbon Fiber 9.7. If you are cycling to win a race for money, a significant difference, if you are just biking not worth the extra costs.

And when other factors come into play, i.e. the need to know the frame will hold up, Chrome Moly wins hands down. Remember we KNOW when a Chrome Moly Frame will break do to Fatigue (and can design the bike so that will NEVER happen), we do NOT know that about the other three materials. This is NOT do to a lack of testing, the other three material tend to be more affected by Fatigue Stress and thus plan unpredictable when they will break do to Fatigue. We can over design (and do) when dealing with these materials so that such break do to Fatigue Stress will NEVER happen, but unlike steel we can NOT give a solid number to when it will break. Thus when metal Fatigue Stress is a factor, people go with Chrome Moly Steel.