Originally Posted by
branko_76
My response to the above post was in no way an invitation to an argument. I simply want to know why a modern mid-range rim like the Sun CR18 is "far superior" to a 1980's rim like the Rigida 13/20. I provided some basic data for the rims which seemed to conflict with your statement of weight, design etc. I wanted to know if there was something about the aluminum alloy used in the Sun CR 18 that was more suited to cycling than older aluminum. That's all.
...I have no idea about the alloy used in each. I think it's proprietary information anyway. But the extrusion and manufacturing process improvements have led (as I stated), to some subtle redistribution of exactly where the alloy material in a rim is located, which has been done in order to improve resistance to deformation and overall durability in real world use. To think otherwise, and simply compare rim weight, is to ignore 40 years of progress in aluminum forming and extrusion. (Mostly in China...but it carries over to other locations if they want to stay competitive).
It is true that not all of the "improvements" have panned out. Anyone who has had to throw away a set of rims that started cracking at the nipple holes can tell you that.
But in general the stuff you can buy today is better for the money than the stuff I was building with in the 80's. Which is what I said originally. Which was a while ago.