adamlesandrini

I have a 1985 fuji sagres and I was wondering what material the rims are made of and what is the different levels of chro-molly (double vs. triple vs. quad).

Blue Order

Rims are almost certainly alloy (aluminum). The tubing is not cromoly-- it's Valite, Fuji's proprietary chromium-vanadium steel alloy. Fuji made Valite frames in everything from single-butted (or maybe even straight gauge) to quad-butted. There will be a decal on your seat tube that tells you the tubing material (Valite), and what type of butting you have.

T-Mar

A 1985 Fuji Sagres should be manufactured from triple butted VaLite tubing. As previously stated, Valite was a proprietary alloy. It was manufactured for Fuji by Ishiwata, one of Japan's leading tubing producers. Mechanically, it has strength properties that put it between the hi-tensile steel used on entry level bicycles bicycles and the chromium-molybdenum steel used on the best vintage, steel bicycles. It is roughly equivalent to the carbon-manganese alloy tubesets found on many upper, entry level and lower mid-range frames in the 1980s.

Triple and quad butting are refinements on double butting that provide marginal improvements in weight and allow some fine tuning of ride quality by providing more variation in the wall thickness. They are not substantially superior to double butting.

Triple butting refers to the thickness of the tubes. In order to save weight, the tubing manfacturers developed processes that thinned out the tubes in the middle, leaving thicker ends to handle the higher stresses where the tubes are joined together. The thicker tube ends are called butts. A tube with no butts is called a plain or straight gauge tube. A tube with only one thicker end is single butted and this type is used primarily for seat tubes, with the butt being located at the highly stressed bottom bracket joint. Tubes with butts of equal thickness at both ends, are called double butted. Triple butted tubing also has butts at both ends but one end is thicker than the other, resulting in three different thickness in the tubing wall. Quad butting provides four thicknesses, with one end of the tubing having two butts of different thicknesses.

A tubeset is typically defined on the basis of its best tube. For instance, a triple butted tubeset may have a triple butted down tube, but only a double butted top tube and a single butted seat tube. Seat stays, chain stays and forks are are not butted but are straight or taper gauges, the last being a process that results in a gradual reduction in wall thickness over the length of the tube.

mrmw

This terrific explanation, in its entirety, should be locked as a sticky.

TBART

I agree, excellent post by T-Mar!