I've been using thick slicks for 15 + years. I also use thornproof tubes. with a liner. Never had a flat when I commuted to work. The other day iIwas riding on the loop in Tucson. Some park maintenance workers. Not city or county, were cleaning up weeds. They blew all the goat heads into the bike path. Buy the time I realized what happened. I jumped off my bike. I had 12 goatheads on front tire and 8 in the rear one. I removed them all and finished my 40 mile ride, many people were not as lucky as me.