It seems like Fuji either used some sort of proprietary tubing on their bikes in the 1980's, or rebranded tubing made by someone else. My 1982 Team Fuji has a decal for double butted 331 cromo. Does anyone perchance know what the rough equivalents of that tubing might be from other manufacturers?

A quick search comes up with this nugget from SCOOPER, from a few years back.
"It appears "331" is a proprietary Fuji chromium molybdenum tubing.

1983 Fuji America catalog page (https://bp3.blogger.com/_P7m8p3pz-zo/...og_Page_10.jpg). Note the frame material is "FUJI 331, double butted chrome molybdenum steel tubing with back stay, chain stay 7" C.P."

Based on the frame pricing in the 1983 catalog, it looks like 331 was second or third in terms of quality among the proprietary Fuji tube sets:

Top of the line

FUJI 9658 quadruple butted chrome molybdenum steel tubing
FUJI 331 double butted chrome molybdenum steel tubing
FUJI VALite 1769 quadruple butted steel tubing
FUJI 441 chrome molybdenum steel tubing
FUJI VALite 212 double butted steel tubing
FUJI VALite 414 butted steel tubing
FUJI 661 high tension steel tubing"

For 1982, they used the 331 on pretty much all of their higher to mid-range bikes, even including the Professional Super Record.

My Fuji is really the only non-gaspipe steel bike I've ridden as an adult, so I'm trying to get a sense as to how it would compare to other marquees for the inevitable N+1 down the road.

I've always thought that 331 was equal to 4130 chromoly steel.

Me too, Bill.

Saying it's "double-butted chrome molybdenum" as described on the '83 Fuji America catalog page doesn't necessarily mean it's exactly the same chemistry as AISI 4130, but close enough.

Cool thread. I just looked at my '83 S-12, It has 441. Brown and gold. Gorgeous paint , chrome and decals on this near mint frame.

I scored this Team at a pawn shop last week. It's an 82 with the 331 decal. I also had a NOS Team from late 82-83 that had the 9658 decal. In my personal opinion the 331 seems lighter than the 4130, but that's just my opinion! :-)





Flash

I sold Fujis in the 70's and 80's and my thought is that the 331 or 441 decal, as stated above, is just their version of 4130 cromoly tubing. Many bike companies had their own decals of cromoly tubing - just look at the USA Raleigh road bikes with 555 and 888 tubing.

Sort of a zombie thread here at this point, but I wanted to follow up for anyone else who might come across this later. FWIW, I had the fork out of my "331" Team the other night, and it has an Ishiwata stamp on it.

That jibes with what I remember T-Mar sharing with us in some post long ago (in the T-Mar Era): he said much of the Fuji tubing was drawn for them by Ishiwata.
Given the size of Fuji and the big orders they would have placed it's possible that they had special alloys or at least weights/gauges in their tubesets...or maybe not.

Yes it seems probable that fuji tubing was Ishiwata. I'm going to assume that 331 was similar if not the same as 022. I know they later used the 019e on their custom Design series frames so I doubt 331 was 019.
The later 9658 is clearly Ishiwata quad butted EXO-M which gauges at .9.6.5.8. This was a less expensive seamed quad butted tubing which saved them money and kept the price down. I would have liked to have seen Fuji use the EXO-L which was 175g lighter and on par with the weight of 019e. They probably didn't because they wanted more strength which would cover a larger customer base to include heavier riders. Less liability.

I eventually had the bike taken apart enough to get a look at the steerer. The brand of the tubing was marked, but not the specific size. I'm about 85% sure that it was Ishiwata, but it *might* have been Tange. Either way, it was definitely one of the major tubing companies making as a private label for Fuji. I sold that particular bike a few years ago, and I don't remember positively.

For the 331 Im going with Ishiwata over Tange since they continued to use Ishiwata through the early to late 80s.
There would only be a few possiblities for what tubing it was, 019, 022 or 024 (doubtful to heavy) I would put my money on 022.