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.
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.
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?
