a listee posted:
>"I can understand wanting to have everything square, in line
>etc....but why the high degree of precision [+ or - 0.001] .
>I can also understand keeping the tolerances during frame
>brazing...but after that does it really mater???
>If you ever get the chance to ride behind a strong rider or
>on a fixed roller [were the forks and bottom bracket are held]
>watch the frame!!!! It moves with every pedal stroke...and i
>mean far!!! Would this not negatively affect the alignment???
>After all it's the same as cold setting...no???
>Why not check the bike for square/align AFTER everything is
>installed [ei.bottom bracket/chainrings etc...] then you could
>address the missalignments do to tolerence stack up in the com-
>ponents???? My line of thought is if the frame is perfect
>[the impossible +/-0.000] and you have 0.002" play in the front
>hub bearings and 0.003" of play in the rear [plus all the rest
>of the parts] the bike is still out of tolerance and alignment
>and technicaly not tracking straight....
>Besides i don't think anyone would ever feel the difference from
>a frame that is set on a table versus built straight in the first
>place [well brazing with normal tolerances]"

my reply:
if i could control everything, i would.
in the meantime, if i start adding up the
margins of error inherent in some manufacturer's
parts, add them to mine, and consider the plusses
and minuses of the mechanic's (that'd be me)
abilitities, there'd be only 2 consequences:
1) nothing would ever get finished, and 2) the
cost of goods would skyrocket.
most tubes are not straight, many parts are
sub-par, and no rider is symmetric. these are
not reasons to cease making frames absolutely
straight and hoping for the best.