Superb article, thanks. My only questions are:
- For the ultegra spider, outer shell bonded to inner part, are they both aluminum parts or is one steel? If both aluminum, I can't see the advantage of bonding two parts together, versus the one-piece 105 spider, with both appearing to be same finished shape, especially at such small mass difference.
- Both ultegra and 105 outer rings show significant "depth of section", thicker, versus traditional rings. I wonder if it's to allow them to be lighter (ultegra is hollow, 105 uses a composite ribbed construction), or they did it to make the rings laterally stiffer (versus traditional rings), for greater shift precision?