Originally Posted by
Kontact
You're wrong.
You haven't read what I wrote or measured these things yourself. You don't know what you're talking about. Here's a database:
https://spokelengthcalculator.com/da...tring=dura+ace
Once you subtract 2mm for the right half of the 4mm axle difference, the listed offset differential for 7400 7 speed and 7403 8 speed is 0.7mm.
And that's because (as I already told you) the cassette shoulder was moved in about 2mm closer to the flange when they went from 7 to 8. You can look down on an assembled 7 speed bike and see the bigger gap between spokes and low cog. You can also look at the shoulders themselves:
Actually the 7 speed freehub body is 4.5mm wider than the 8 speed freehub body. In order to do what you are suggesting, you would have to move the end of the freehub 2.5mm closer to the locknut. And there simply isn't 2.5mm to spare on most road bikes on that end before the chain rubs the seat stay or the small cog rubs the chainstay.
Also- go and look up the Shimano diagrams for the FH1055 vs FH1056; and FH6401 vs FH6402. These hubs have identical hub bodies and similar HG freehubs (aside from the lengths of the freehubs), so they are good for direct comparison. For the FH105*, the left lock nut got moved out 0.7mm. For the FH64**, it was 1.1mm. So that means the right would have moved by 3.3mm and 2.9mm. Definitely not symmetrical. The dishing definitely got worse.