Is there a reasonable explanation for Ishiwata Magny tubing?
 

There's a mid-80s Japanese-made Bianchi near me that's my size and looks to be in good shape. Can't remember the model--something mid-level from all appearances. I don't want it (much) and certainly don't need it. But I am wondering about it. I noticed that it had an Ishiwata Magny decal, which interested me because I don't know anything about it. So I poked around a little bit, and found this C&V thread from a few years back:

https://www.bikeforums.net/classic-v...e-opening.html

The provenance of the chart at the opening of the thread is pretty vague. But if it's to be believed, then Ishwata Magny (I'm simplifying a little, since there are two versions, which vary slightly in weight) weighs about two pounds more than Ishwata 022. I realize that's the tubeset not the frame, but still. Magny seems to have been the heaviest thing out there by far--heavier, even, than hi-ten.

Why in the world would that be the case? Did someone in Ishiwata's marketing department decide that super-heavy tubing was the wave of the future? Did it have some other compensating virtue? It doesn't seem to have been especially low-cost, given that it seems to have been used mostly on solidly mid-range bikes. Another explanation might be that it was specced for frames that needed extra strength or stiffness. If so you would expect it to show up mostly on things like touring bikes, but I don't think I've ever seen it on a tourer. Maybe it was originally designed for BMX bikes and such, and somehow spilled over into the road-bike world for a time?

Or is it possible that the chart is just wrong? Sure, it's on the Internet and everything, but I once heard an unconfirmed rumor of an error on the Internet. Could this possibly be a second Internet error? That seems unlikely, but I suppose it's possible.

Does anyone have insight on this?

Don't know anything about Ishiwata and Bianchi but, Ishiwata supplied the tubing for most of the Fuji bikes made in the 70 's & 80's. Fuji also developed frame welding robotics using Ishiwtata tubing.

I think you may have discovered something on the interwebs that is not entirely true. Shocking, I know.

I think it's just a typo. The gauges are exactly the same as 022, therefore a tubeset should weigh about the same. If the butt lengths are different I suppose it could differ by a few grams, but I think in this case they simply typed a 3 where there should have been a 2.

IIRC magny was Ishiwata's brand of manganese molybdenum(?) steel, basically similar to 531.

Here is another thread with a much lighter claimed weight. It's from @T-Mar so I'll bet it's right! Scroll to post 3:

https://www.bikeforums.net/classic-v...ta-tubing.html

I believe it would be more akin to Tange Mangaloy 2001 than to Reynolds 531.
https://cimg0.ibsrv.net/gimg/bikefor...24803ea9ef.jpg

That's what I thought as well but it doesn't get much respect unlike the Japanese chrome moly tubing sets which do.

Manganese was quite the thing for a few years there, wasn't it? You had your Maglite, your Mangaloy, your Magny...what am I forgetting?

EDIT: Wait, was there even any such thing as Maglite tubing, or did I imagine it? Is it the stuff the barrels of those big flashlights are made out of?

Is not manganese the trace metal in Reynolds 531 steel?

Manganese and molybdenum, I think.

You're probably thinking of Miyata's Mangalight. There was also Columbus Aelle and Aelle R. Tange had a lighter version of 2001,called 2001S. All are classified as carbon-manganese (CMn) alloys, as opposed to the manganese-molybdenum (MnMo) of Reynolds 531. Carbon-manganese tubests started appearing in the very late 1970s and filled the gap between hi-tensile and CrMo. It's tensile strength lay between the two but it retained a higher percentage of it's strength after brazing than CrMo. However, more importantly, it was tolerant of higher temperatures, making it suitable for automated brazing processes used in mass production. It was instrumental in lowering the price of lightweight butted framesets in the early 1980s, as highly paid skilled brazers were not required, as with CrMo.


The referenced chart is from the July 1982 issue of Bicycling magazine and, as noted,is in error. Exact weights vary depending on the source and year but the density of steel does not vary significantly by alloy so the 3+kg figures do not pass a sanity check. Manfacturers typically made their carbon manganese sets slightly heavier than CrMo sets, otherwise the higher cost of CrMo couldn't be justified. The figures I've seen are typically in the 2200-2500g range.

They used to make bikes out of flashlights back in the day . . .

Yeah, that's it! I was in the right ballpark. Well, sort of.

Thanks for the info, T-mar. I was hoping you'd chime in.

I've been reading and learning from your posts for years, and finally I have to ask: How come you know all this stuff? You must have been involved in the industry for some time, yes? Where? When? How? I mean, if I'm not being impertinent or a pain in the butt....

It had something to do with The Brady Bunch, as I recall.