Originally Posted by
zzzwillzzz
steve, do they make different lug angles for the down tube/head tube junction and also for the bottom bracket shell? those lugs would have the most change in angle depending on the size and length of the top tube. or is there some play built into them?
Some makers do. A "standard" angle from seat tube to downtube is 60 deg. You have some play in
the crankshell sockets (and you can cold set) to adjust that open or closed by a few degrees.
DT / HT angle is also basically 60 + / - 1 deg. Some lower head lugs can be gotten
in 59 and 61 degrees. Uppers are available as 73 and 74. Again, some room for adjustment
by bending the lug a bit.
These are investment cast lugs (most are now) and run very tight. The old stamped and formed
steel lugs could be twisted all over the place giving lots of adjustment.