As a child, I was always barefoot, unless I had to wear shoes, so the spiked weapons the British used to stop the barefoot Indians from approaching the fort had a big impact on me. They looked like the toy Jacks we played with as kids, except they had spikes on the ends.
These would play havoc on motorcycles. For that matter, even on car tires. The only picture I could find of them had a twist of humor I'm sure will bring a smile to many faces.
I remember a news story from decades ago that showed what looked like 16-penny nails bent and welded together in that shape. The striking Teamsters were throwing them in front of scab drivers’ truck tires.