I'm getting a lot of questions off list that I covered in a post:
Measuring: For fork rake I have a plexiglas gage called a "Gabe Meter" made in Germany in the early 1980s that has a v-block (with magnets) on the back that attaches at the top of the fork leg that has a scale you read at the pointed end of the QR.
Almost as easy is to use a 4' metal straight edge, lining up the center line of stem bolt, fork crown and upper fork blade, then calipers to measure to axle center.
For calculating trail:
http://www.kreuzotter.de/
For head angle and seat angle I use a 4' long metal straight edge along top tube and a draftsman's 14" adjustable triangle that has a degree scale on it to measure the angle.
I think this is much more accurate than one of those angle finders that relies on leveling the top tube first (fluid filled, with floating pointer?).
I also use the 4' metal straight edge and a vernier caliper to measure the BB drop.
Chainstay is measured to the middle of the drop out.
Here's an example: ~~~~~~~~~~~~~~~~~~~~~ 1960 CINELLI SC #7094 (center to center) Seat Tube -- 55.5cm Top Tube -- 56.0cm BB drop -- 8.0cm Chain Stay -- 42.5cm Wheel base -- 102.0cm Seat Tube < -- 73.0° Head Tube < -- 73.0° Fork Rake -- 5.5cm Trail -- 4.6cm* *wheel dia. 68.0cm ~~~~~~~~~~~~~~~~~~~~~
Also a lot of questions about "which bikes should I measure?"
I measured some of mine (eventually all) because I was curious as how they compare to each other (also the different eras). If you have any curiosity at all, I would assume you'd want to know how the bikes you ride compare in geometry.
PLEASE NOTE: ABSOLUTELY DO NOT QUOTE ANGLES AND DIMENSIONS LISTED IN BROCHURES OR CATALOGS !!!
Chuck Schmidt South Pasadena, Southern California
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