I made these securing points to reduce the risk of theft of our 2 new Rad bikes. I welded a truck load securing "D"ring to a drilled plate.
Then I epoxy grouted the mounting studs and plate to the concrete floor pad. The bolt head is in the hole so the only way to get the stud out is break or grind it off. The nut on the top was prewelded to prevent this from coming off. You can not prevent bike theft but you can slow them down. By the time they get this and the cable and/or U lock or the plate loose the dogs will be barking and we will catch or stop the thieves. We also have a wireless Arlo camera watching the bikes. Paranoid? No I think just reducing the risk factor when the bikes are parked especially at night in the carport.