What Ever Happened to Scandium Bike Frames? (2016) | Hacker News Reader

What Ever Happened to Scandium Bike Frames? (2016)

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101 pointsaranchelk29 comments

Some high-end Smith and Wesson revolvers use scandium-aluminum alloys in exactly the same way to reduce weight. It does seem to be an alloy that is restricted to high end consumer goods in hobbies where consumers are willing to pay to avoid ounces - my guess is it would also appear in some specialty backpacking gear.

I was curious, but I couldn't find much. Apparently a manufacturer called Yunan made Scandium tent poles ("Yunan Air Hercules"). Maybe they made other Scandium equipment, and maybe at they're still making it.

That's all I could find in a couple of minutes. Apart from tent poles, backpack frames, and cooking equipment, there isn't a lot of metal in backpacking gear. I guess there's more of it in (high) alpine stuff... Climbing gear, crampons, ... But no Scandium that I could find (plenty of aluminum, though).

http://www.yunanalu.com/company1.php

In my experience the high end backpacking gear metal of choice is titanium.

On-One bikes made - and still make [0]- a bike called the ScandAl. Clever name, orignally marketed as Scandium and a cute logo with atomic number of the elements in it. Mine cracked just like the one in the article picture (to be fair, after a decade of hard use).

[0] https://www.planetx.co.uk/c/q/bikes/mountain-bikes/on-one-sc...

Expensive and probably just not worth the benefits compared to more conventional alloys and you can also make carbon fiber or titanium bikes. Magnesium-alloy bikes are also quite rare and beryllium even more so.

Right, scandium isn't a selling point any more because the market niche for aluminum in the high end disappeared. If you want a fancy metal bike you can get a titanium frame. If you just want objectively great performance you can get carbon. If you insist on something clearly obsolete, you can get chromoly. Where does that leave aluminum?

Isn't most titanium sourced from Russia? (Ironically, that may include the titanium used in modern Western howitzers to make them lighter and helo-transportable.) If so, we may see some shortages in the future?

Similar story for the SR-71, it was mostly made of titanium sourced (indirectly of course) from the Soviet Union.

According to wikipedia its from other countries China, Australia, Mozambique, Canada, etc. https://en.wikipedia.org/wiki/Titanium

Chromoly, obsolete? I don't think so. Steel is real!

I though arwwl was what you wanted on a reliable long distance touring bike, where weight wasn't much of a factor, but durability and flexibility was.

lol

arrwl --> steel

Exactly, for a short while weird Al alloys were all the rage and manufacturers were advertising new wonder materials or taunting the benefit of Al 7005 over 7020 etc.. Realistically compared to welding, design, etc. the alloy gives questionable benefit for an increase in price and more difficult manufacturing. We see something similar with the advertising of different carbon toray numbers.

The cycling industry is quite interesting. Their advertising is trying to give the impression of a high tech industry with plenty of R&D and every year you read about the most recent "breakthrough" (aero/weight/compliance). However even the largest bike manufacturers have maximum a a few tens of engineers who develop the bikes and components across the whole range. That already tells you how much R&D they can do realistically.

There are a few of ski manufacturers making Scandium-based/reinforced skis.

TL;DR scandium is a very expensive byproduct of uranium mining, at least in Ukraine. The Soviet Union pioneered using it to produce very strong aluminum alloys, and after the fall of the .su, the technology became available in the west. The market for scandium is small, and had some PR problems due to knockoffs of poor quality, but it never went away and high end aluminum racing components still use it, and high end aluminum frames you might purchase likely contain it also.

I thought it was interesting that they mention that 6061 aluminum sometimes contains scandium. I would have thought that 6061 was a more well-defined standard, that you couldn't add other things and still call it 6061.

(I've done a bit of TIG welding and mainly use 6061.)

Like with everything, there are engineering tolerances.

6061 can have up to 0.15% "Other", as long as no single "Other" component is more than 0.05%. So no more than 0.05% scandium if you want to call it 6061.

See https://www.gabrian.com/6061-aluminum-properties/

This seemed like marketing speak to me so I went looking for research on it. I found something which was interesting:

For instance, the addition of Sc and Zr to 6061 alloy shows a slower ageing response at 190 °C, resulting in lower yield strength of 321 MPa (aged for 5 h) than base 6061 alloys (350 MPa) [64]. On prolonged ageing (36 h), a significant drop (~ 19%) in the yield strength of 6061 alloys was reported compared to only a ~ 6% drop in ScZr-modified 6061 alloys. [1]

I wonder if I am reading this right or if 6061 is actually not very alloyable with scandium.

https://link.springer.com/article/10.1007/s12666-022-02547-z

So it slows heat ageing, which is both good and bad because during that process the metal hits a peak strength and then declines?

The paper you linked puts the solubility of Sc around 0.25% in Al. They have some cool TEM work in there looking at how Zn modifies the ordered ScAl3 precipitates that form during aging, which I think is the context for the bit you quoted.

Seems like the main difficulty in these alloys is that the Sc changes the solubility of the copper?

For context for those not familiar, precipitation hardening (aging) is the principal way to increase strength in Al alloys since you can’t quench harden them https://en.m.wikipedia.org/wiki/Precipitation_hardening

25+ years of use and my scandi-Kona is still going strong.

Good to hear. Today I used my 2010 scandium Kona for the first time this year. Has a creaking noise I need to track down.

Followup: Whatever happened to butted aluminum tubing?

High end alu frames have sophisticated butting done by blasting water into the metal.

Double, triple etc butting still exists but it’s not a marketable feature anymore now that hydroformed aluminum and carbon fiber frames have entered the market.

I have a scandium Eddie Merkz. It's awesome! So stiff and light but not harsh like an aluminum frame.

Eddy Merckx :)

harshness of aluminum is mostly mythological and based on design of some early aluminum frames due to them being noisy. also 99.9% of compliance comes from tires. people reliably fail to detect frame differences in blind studies as well. even people who are professionals and people who insist the difference is obvious.

My circa 2000 aluminum bike (Cannondale CAAD 4) is my only reference point. It is definitely harsher than my circa '98 titanium Litespeed or my 2005 steel Surly Pacer.

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