I have a First Manufacturing (yeah I know) leather jacket that is not armored, but I was thinking about adding at least elbow armor, . The jacket has a removable thermal liner, and under that is a permanent mesh lining.
Would it be feasible to attached the armor with Velcro? Soft side on the jacket, prickly side on the armor...? This would allow placement adjustment as well as removability. It seems that Velcro, attached with Gorilla Glue, and fully covering the pieces of armor, will actually hold their position better than with a built-in pocket sewn onto the mesh lining (like most armored jackets are). AFAIK, the armor just has to stay in place during the jacket's normal use, up until the point of impact...It doesn't necessarily have to hold it's place for the rider to slide on, as if anyone would be sliding on their elbows anyway.
A product like this perhaps: http://www.motorcyclegear.com/street/armor/elbow_shoulder_knee:_installs_in_apparel/joe_rocket/ce_motorcycle_armor_for_jackets_pants_and_suits.html
If anyone has any experience with this, or better ideas, or reasons why this is a bad idea altogether, I'd love to hear.