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-   -   Frame Geometry Database (https://www.bikeforums.net/classic-vintage/234516-frame-geometry-database.html)

pinnah 10-05-06 06:36 AM

Frame Geometry Database
 
All,

Could you post frame geometry information for your bikes? Links to catalog scans would also be greatly appreciated.

The information I need are:
Manufacturer, Model, Frame Size (seat tube length), Head Angle, Seat Tube Angle, Fork Offset (rake), Chainstay Length.

Information that would be nice to have are:
(Effective) Top Tube Length, Bottom Bracket Drop, Wheelbase.

My strong preferance is for data from 56 or 58 cm frames.

I'm compiling a database (OK, its a spreadsheet) of vintage and current bike geometries. My interest here is a) to archive as many as possible in a central location and b) to look for groupings of tried and true classic designs.
The spreadsheet is available for download here:
http://home.comcast.net/~pinnah/dirt...kes/bikes.html

For those who are interested in such things, I can see several groupings in the geometry data. Arguably there are 2 more that could be called out...



Modern Road Racing Bikes
-----------------------------------
Chainstays approximately 41.0 cm
Head Angle approximately 73.5 degrees
Fork Offset approximately 4.3 cm

Classic Road Racing Bikes
----------------------------------
Chainstays less than 41.5 cm
Head Angle approximately 73.0 degrees
Fork Offset approximately 4.5 cm


Event/Audux/Century Bikes
----------------------------------
Chainstays approximately 42.5 cm
Head Angle approximately 73.0 degrees
Fork Offset approximately 4.5 cm


Modern Sport Touring Bikes
-----------------------------------
Chainstays between 43 cm and 44.5 cm
Head Angle approximately 73.0 degrees
Fork Offset approximately 4.5 cm


Classic Sport Touring Bikes (My Favorite)
-------------------------------------------------
Chainstays between 43 cm and 44.5 cm
Head Angle approximately 73.0 degrees
Fork Offset approximately 5.5 cm


Loaded Touring Bikes
------------------------------
Chainstays greater than 45 cm
Head Angle approximately 72.5 degrees
Fork Offset approximately 5.2 cm

John E 10-05-06 08:32 AM

1 Attachment(s)
How old is "classic" on your chart? My ca. 1960 Capo frames are 72 degrees parallel, as is the 1970 UO-8.

pinnah 10-05-06 09:32 AM

The oldest data I have is from the 50s (mercian) but realistically the data stops in the 70s. Finding frame info before that is very hard.

Would love to add your frame data. But, really need fork offset (rake) and chainstay lengths


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