Element 21 on the periodic chart, Scandium, is a very rare metal, produced as a by-product of uranium processing, with little commercial applications—outside of marketing!
That said, the scandium-aluminum alloy frames that I have seen are impressively light by very-light standards and seem to hold up well. The tubing is however, in my humble opinion, no good for loaded touring. It is one of the stings of the miracle disposable racing tube sets that seem to be everywhere. Loaded touring, I feel, puts more stress on a bike than racing. Having broken my share of racing and touring frames, I feel that almost any will fail given enough miles, but super-light tubing is just that, and will have a shorter road life.
On a sad note, we have a friend of the shop that had a Scandium bike built by a major manufacturer. After less than 2000 trouble-free miles, he brought it into the shop for an annual look-over and what was found was that the right-rear chainstay was cracking in two! After telling the fellow the bad news, it got worse: the other chainstay was broken half way around too!
This unnamed manufacturer probably has many thousands of these bikes on the road and most of them probably are fine, if used as intended. I hope this is an anomaly, but it makes you wonder. It's hard to beat steel for reliability. But aluminum, in the same weight range, is probably just as reliable. However no one makes heavier aluminum frames anymore, except for sale at Wal-Mart—and those are are much heavier than steel frames and, from our experience, much less reliable.
Yours in Cycling,
North Road Bicycle Imports
P.O. Box 840
166 Courthouse Square
Yanceyville, NC 27379
toll free: 800-321-5511