I wonder how i have to enter data in the tubing-size section in order to create a mitering template for tubing which is neither round nor oval, like for exeple some Columbus and Deda tubes.
Concretely i'm working on one of the Spirit top tubes which is kind of oval, but with a flat top and sides. The diameter is given as 31.7mm, dimensions are 33.5x28mm.
thanks in advance for your heip
Interesting that you should ask this as the same question came up a few times this weekend at NAHBS. The BikeCAD booth was right across the aisle from the Columbus booth. Unfortunately, there is currently no way to enter a specific tube cross section such as that into BikeCAD. Of course, if you were joining that to a round head tube, you could obtain a perfect miter using a hole cut saw. If you're joining to a tapered head tube, or don't have access to a mill and are therefore determined to use a miter template, I'd think you wouldn't go too far wrong approximating that tube as an elliptical cross section. However, I have not actually tried it, so I can't be sure that such an approximation would be up to your standards.