Originally Posted by
unterhausen
There were a lot of 531 bikes made with the 28x20 blades, my 531 bike has them. I really like the way my 531 bike rides, but I was always happier with Columbus tubes. I have no recollection of why I built this one with 531 instead. Nowadays, I like to build with Columbus SL reissue
When I started this stuff the supply chains were more England then Continental based, at least in the East of NA. ( Cycle Imports and Proteus). So the tubing was Reynolds and at that time the standard blades were the 28.5x16.5 shape. Soon enough the racing focus and it's love of anything Italian took over and Reynolds SL sets with the 28x20 shape was the gig. I can say that about every frame I've done since about 1982 has been with the 20x28 shape, regardless of the brand.
I could say something about the wider blades' stiffness, but then I'd sound like a marketing guy. Because both shapes get you up that hill just fine. Andy