Frame Geometry - Cut once measure twice
With the back wheel installed on the
bike vice, the target ride height is set.
Using blocks of wood, the frame in then
leveled with the table. A ratchet strap
is used to keep the frame locked into
Using a plum-bob, the frame center line
was measured and translated onto the table.
The placement of the stock neck was also
marked. The center line will be used during
the frame stretch and rebuild process.
Using a square, the stock rake was measured
at 30*, stock softtails range from 31*
to 33*. The difference here is that the
frame is now parallel to table. Stock
softtails have a 1* to 3* incline. Using
simple maths, the rake can be calculated
to 30*. Horizontal(x) = 3.5, Vertical(y)=6.
ATAN (x/y) = rake
Various points on the frame were measured
and entered into the computer. The black
indicates the frame parts that will remain
stock while the purple represents frame
parts that can change. The current fork
tubes are 2" over and the new ones 10"
over. These are drawn in the upper corner.
The computer allows for changes, in rake,
trail, upper and back bone stretch without
making any welds. This is the target frame
geometry we plan to use.
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