Welcome to the JH Choppers 1997 FXSTC
Chopper Project Page.
Chopper Frame Geometry 101, cut once measure twice.
Chopper Frame Geometry 101, cut once measure twice.
| Frame
Level and Lock Down: 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 place. |  |
| Record
the Center Line: 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. |  |
| High School Trig: And you thought you would never use this stuff in real life... Using simple
math, the rake can be calculated to 30* |   |
|
Measure the Frame Rake: Using
a square, the stock rake was measured at 30*, stock softails range from 31* to
33*. The difference here is that the frame is now parallel to table. Stock softails
have a 1* to 3* incline on the bottom rail. |
 |
 Various points on the
frame were measured and entered into a computer. The black indicates the frame
parts that will remain stock while the purple represents the frame parts will
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. | |
