Both aluminum and steel have their advantages when it comes to bicycle frame building. Steel is much easier to weld than aluminum, so it's less likely that a steel frame can be defective.


The density of steel is 7.85 Mg/m3 while the density of aluminum is generally around 2.72 Mg/m3. This means that steel is almost 3 times heavier than aluminum when you have the same volume of material!

In terms of strength when it comes to bicycle frames, steel is stronger. There is no argument about this. Steel has what is called a endurance limit, where as aluminum will continue to degrade and fatigue as you stress it more. In street biking or mountain biking, where you are always putting a lot of stress in multiple directions on the frame, steel is probably a better material.

The reason that you cannot use less material with steel frames is because the material has a naturally springy property. If you use to little, the frame will be far too flexy for anyone to ride. In applications where you want the frame to be lighter, aluminum is a better choice. You can engineer the frame to be stronger in certain areas with an aluminum frame, and still have it stronger. This is better for trials riding, because we usually only apply stress to the frame from one direction. Aluminum also makes for a much stiffer frame, which is important when we are riding trials.

The conclusion is, that there is really no point in building trials bikes out of steel. However, high quality steel frames will always last longer than aluminum frames.