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What Ever Happened to Scandium Bike Frames? (2016)
- fsckboy 4y agoTL;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.
- elihu 4y agoI 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.)
- ddulaney 4y agoLike 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/ https://www.gabrian.com/6061-aluminum-properties/
- Hextinium 4y agoThis 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 https://link.springer.com/article/10.1007/s12666-022-02547-z
- Dylan16807 4y agoSo it slows heat ageing, which is both good and bad because during that process the metal hits a peak strength and then declines?
- rsfern 4y agoThe 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 https://en.m.wikipedia.org/wiki/Precipitation_hardening
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- slavboj 4y agoSome 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.
- morsch 4y agoI 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 http://www.yunanalu.com/company1.php
- Consultant32452 4y agoIn my experience the high end backpacking gear metal of choice is titanium.
- kevin_thibedeau 4y agoFollowup: Whatever happened to butted aluminum tubing?
- s0rce 4y agoExpensive 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.
- jeffbee 4y agoRight, 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?
- inglor_cz 4y agoIsn'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?
- HPsquared 4y agoSimilar story for the SR-71, it was mostly made of titanium sourced (indirectly of course) from the Soviet Union.
- s0rce 4y agoAccording to wikipedia its from other countries China, Australia, Mozambique, Canada, etc. https://en.wikipedia.org/wiki/Titanium https://en.wikipedia.org/wiki/Titanium
- ohg 4y agoChromoly, obsolete? I don't think so. Steel is real!
- m463 4y agoI 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.
- zh3 4y agoOn-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-scandal https://www.planetx.co.uk/c/q/bikes/mountain-bikes/on-one-sc...
- diziet 4y agoThere are a few of ski manufacturers making Scandium-based/reinforced skis.
- hasbot 4y agoI have a scandium Eddie Merkz. It's awesome! So stiff and light but not harsh like an aluminum frame.
- Luc 4y agoEddy Merckx :)
- gameswithgo 4y agoharshness 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.
- hasbot 4y agoMy 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.
- nickdothutton 4y ago25+ years of use and my scandi-Kona is still going strong.
- StayTrue 4y agoGood to hear. Today I used my 2010 scandium Kona for the first time this year. Has a creaking noise I need to track down.