I recently got Lennard Zinn's book The Art Of Mountain Bike Maintenance. Not a bad book and the lad seems to know his stuff. Anyway, he comments on chain line calculations where you do a number of measurements between down tube and chainset, and between rear drop outs and cassette, etc. After a bit of math and spooky magic, you end up with a number, that providing it's a number of millimeters in a certain range will tell you if the chain line is correctly set or not.
That got me thinking about that. I suppose carefully built bikes at the top-end of the market would be correctly setup, but does that imply that bikes at the lower end of the price range would have a chain line that's sloppily setup?
Further, does it actually matter? I suppose the purist would strive towards that but us lesser mortals would not be too bothered?
Finally, if the chain line calculation is not correct, how do you go about setting it? As I see it, you can't do much at the rear wheel, and the only thing I can see at the bb you could tinker with is whether you can adjust the bb left or right to get the desired chain line calculation.
What idead do you folk have on this?