pic: Bumper idea - legal?

[KarenH]

Originally Posted by Chris is me

Instead of velcro, perhaps a line of several snap fasteners would work better. Same repeatability, a bit more grip.

Caution re: snap fasteners. I think Velcro is a bit easier to work with. Snap fasteners:
--can be tricky to attach. You have to get it right on the first try.
--must be precisely aligned
--can sometimes be difficult to fasten
--often come unsnapped when under stress

There's a reason Velcro has outstripped snap fasteners in popularity. So be sure to experiment and test, test, test with extra fabric and bumper assemblies before committing to using snap fasteners on your competition bumpers.

Thread shouldn't be a problem; use of fabric implies use of thread, even more so than use of aluminum or steel implies use of welding. Thread is not generally regarded as a "fastener" the way buttons, snaps, and Velcro are.

Invisible thread would solve the problem of color matching. Sulky brand invisible thread is nicer to work with than some others, but I don't know if it's as strong. Sewing a second line of stitching over the first line of stitching is a good way to make a strong seam using any kind of thread.