why is steel stronger than iron?
You just need to check the pressure is what the handbook specifies when the tyre is cold, NOT after you have ridden.
no i don't think 2 pounds of air is going to make a difference.
Since the ionic bonding of steel (Steel:Carbon+Iron) is stronger than the metallic bonding present in Iron
Strength of metals is normally measured by the tensile strength as the main measure although this is not the only property as hardness is another big factor. Basically, iron is soft and steel is hard. Plain iron is stretchy and does not corrode quickly, whereas steel is much stiffer and corrodes more quickly. The tensile strength of cold worked iron is about half that of an average steel, likewise the hardness is about half that of steel too. Pure iron, which is rarely used, is even weaker and softer again and a bit more like softer materials like copper and aluminium. Where confusion comes in is that there is another iron - Cast Iron - which is totally different to both iron and steel. Cast iron is very hard and tough but incredibly brittle so its properties are very different.
Every material is made up of atoms which are very small parts. Some atoms hold together quite well, which is what makes some solid materials hard. Something made of pure iron is softer than steel because the atoms can slip over one another. If other atoms like carbon are added, they are different from iron atoms and stop the iron atoms from sliding apart so easily. This makes the metal stronger and harder.
