Originally Posted by IcySmooth52

It's good someone had said this earlier on the thread. I'm going to go over why certain materials are known for certain ride characteristics:

Steel is known for a buttery smooth ride because it's such a stiff material (high tensile strength). This makes for a commonly compliant ride over bumps because they make the tubes so small in comparison to others. It's so strong they don't have to use as much of it, and it makes the tubes more flexible in general.

Aluminum has the opposite appreciation for being so stiff, even though it's a softer material. The tubes are bigger, because aluminum is weaker. They make it bigger to be as strong as the steel lengthwise of the tube, but this happens to affect its strength in other ways as well. Aluminums density makes it so much lighter compared to steel.

Titanium isn't known for a ride quite as smooth as steel, or a rough as aluminum. This is because it's slightly weaker that steel (tensile wise), and slightly denser than aluminum. So you have tubes that typically range in size from steel to aluminum.

Carbon is known to be smooth and stiff. This is because it has many different properties, depending on which carbon material is used. The bigger reason it's so popular is how easy it is to work with to make shapes.

Shapes are a bigger factor in a bike's ride than material, and that's why they still make crit racers from steel and comfort bikes from aluminum.