Dickey Greer wrote:
> It doesn't bother me that the head tube and steer tube are not db
> 531. These are 2 tubes that you don't want any flex at all.
No Reynolds 531 head tubes or steerers were ever DB. (A DB head tube can be approximated by starting with a thick one and relieving the center, leaving it thick at the ends, but that's only done for lugless frames -- and extremely rare in the CR time period)
A 531 head tube is plain gauge, and typically the same weight/thickness/stiffness as the welded item or pretty close. Head tubes have to fit lugs on the outside diameter and headsets on the inside, so they hardly vary at all in thickness from one brand of tube to the next. The reason 531 is better than a seamed one is strength and fatigue endurance -- the cheap one is more likely to crack in use. There is no advantage to the cheap steerer other than cost.
A 531 steerer is the same weight/thickness/stiffness as the cheap item
for most of its length. Again, the steerer has to fit the headset on
the outside and the stem on the inside, so there's no room for making
them any thicker or thinner. 531 is butted (heavier) at the bottom
where bending and fatigue cracks are most likely. The cheaper steerer
may be sleeved at the bottom to approximate the advantage of a real
butt, but it won't be better than a real butt in any way I can imagine,
other than cost, and will almost certainly be weaker.
> I do have an all 531db TREK bike that has a Tange fork
> from the factory. The Yellow Jersey in Madison, who used
> to be a top Trek Dealer said that was normal.
If the tube decal says "Guaranteed built with Reynolds 531 butted tubes, forks and stays", and it came from the factory with a Tange fork, well that may be considered "normal" by some, but it is FRAUD. Tange made good tubing, nothing wrong with it, but if Trek said it was Reynolds, then they lied.
Mark Bulgier
Seattle, WA USA