Got a Colorado Cyclist catalog and there are some bikes in there with a very different looking head. They use a 1 1/8" top bearing and a 1 1/2" bottom bearing. This supposedly increases stiffness, durability, whatever.
Gimmick? Trend?
Principia started this (I do believe), though I don’t remember if it’s a 1" top, 1 1/8" bottom, but the bearing diameters are different top and bottom. I will think of the benefit in a little while, though there is something to do with the load placed on bearings, and the ability to use a larger headtube to make a better joint for the downtube. Also, Isaac bikes (engineered by Principia) do this (I think, I will have to check).
If you had asked me who makes the finest production aluminium bikes, I would say that either Principia, Klein, or Cervelo. I am not counting the customs like the Mandarics or anything like that. But if Principia did it, I would definitely take notice. They still don’t paint frames (I don’t believe; only anodise) and somehow anodise the inside of the tubes (unless I misread their website).*
What I am saying is that there has to be some sort of benefit if somebody who does aluminium bikes right did it first. But it could also be gimmic.
*Edit: they do paint frames these days, but to find out their sales pitch on 1 1/4" bottom, 1 1/8" top head tubes, go to: http://www.principia.dk/
I believe that the high end kuotas have this as well including the kalibur…
My vote if or gimmick. While their may be some theoretical benefit about a million bikes have been made the current standards with no real problems.
Styrrell
Principia started this (I do believe)
Isn’t Principia in receivership (or Euro Community version of reorganization) due to cash flow problems?