Seat Stay/Set Tub intersection.

Dimension F is the distance from the end of the seat stay to the centerline of the seat tube measured perpendicular to the seat tube. Describing it in words like this is cumbersome. I'd rather just show the dimension in a diagram as you see above. BikeCAD does not however allow you to input this value. Instead this dimension is driven by dimension Z. Notice how dimension F changes when Z is made larger or smaller.

Dimension F was included in the diagram because this dimension can be shown with a checkbox in the Dimensions dialog box. It was greyed out, however, because you cannot directly change its value.

Brent, I realize I'm bringing up a zombie thread, but had an additional question for the F Value as it relates to mitering this joint. For setup of a mitering fixture, I use the miter angle output from BikeCAD, and make the appropriate shift of my cutter to compensate for the angle change. Should the F value be added to that number to accomodate for where the cutter needs to be for a first time cut? Apologies if it's not clear, happy to reach out directly to discuss further.

Since you are accounting for dimension Z, I don't think you necessarily need to also account for F. But it really depends on your fixture setup. The point I think I need to make clear is that both F and Z are distances from the centerline of the seat tube to the point at which the centerline of the seatstay intersects the surface of the seat tube. Dimensions F and Z can be thought of as X and Y components of the radius of the seat tube.

Thanks Brent! Yes, I normally try and shoot for the Z Dimension upon setup, mainly just eyeballing to ensure no overlap, and weld clearance.

That helps a lot.