Mine's not a Tri-Glide, but I found this thread interesting.
Tour Pac, Daily Rides: Rain gear, jacket, rags, tire gauge, phone charger (I put a power outlet in), with room left for my helmet, plus leather and other gear when the weather calls for it.
Trunk, Daily Rides: Tire tool, tool kit,
1 extra gallon of gas and an extra quart of motor oil (Old Harleys leak a little
)
Tour Pac, Long Trips: Same as above, but rearranged to accommodate a small travel bag.
Trunk, Long Trips: Same as above, but add
an additional gallon of gas (never trust a 32 year old gas gauge
) and quart of oil, and another travel bag.
Anything else I may need goes in a pack tied to the rear seat (wife doesn't like to ride) and/or in a removable barrel bag tied to the rack on the Tour Pac. Basically, ten pounds of dookey in a five pound bag!
PEACE and ride safe!