Don,
I quite agree that it is possible to calculate the size of a decal using the known sizes of bicycle tubes. The margin of error is probably fairly small if one has a decent photograph. My problem is that I only have a very fuzzy photo off ebay, taken from a less than ideal angle. So I was rather hoping that someone somewhere had one of these things, seeing as how Legnanos seem to have a bit of a following among list members. Of course, if there are very few of these decals about, who will know if I get it wrong?
Hugh Thornton Cheshire, England
In a message dated 15/01/2007 22:39:42 GMT Standard Time, gillies@cs.ubc.ca writes:
With a picture from a bicycle tube you usually have known dimensions. Using these dimension you can scan and import the picture into a CAD program like autocad, MS-Visio, or Adobe Illustrator, and then scale up the picture to match the grid on the background of the cad surface.
Once the picture is properly imported and scaled, you can take pecise measurements of the decal using the software (subject to the fact that it is wrapped on a tube and then projected onto a flat screen.)
For example, you can draw lines and use the "show properties" menu of the line to measure things in the picture. So if the decal wraps around the tube and has been properly scaled, you should be able to sketch a line and measure the line to find the height of the decal. As for the width of the decal - assumning that it wraps width-wise around the downtube - you'll need to measure some width of the decal (100%, 50%, 25%) in inches and then use trig to calculate the overall width of the decal.