I’ve become fixated on packing only the absolutely needed items for my tour. I’m sure extra weight will be regrettable on day 1, as will a forgotten necessity. So I’ve started a list, slowly narrowing it down; packing and repacking; weighing it each time. Here’s where I’m at thus far:

Socks — wool or synthetic (2 or 3 pair) 

Bike touring sneakers
Sandals
Rain jacket
Rain pants
2 Short-sleeved shirts 

1 Light, long-sleeved shirt 

2 Pair Shorts
Military Thermal Underwear
Wool or fleece hat

Wool sweater or fleece jacket
rear view mirror
Solar powered charger
Sansa MP3 Player and speaker
Spare AAA batteries
Sleeping bag
Crashpad
Tent and ground tarp
Jetboil stove
2 Jetboil fuels
Coffee Press
Citronella oil
Lightweight Towel
Basic first-aid kit
Sunglasses
Orange safety triangle
Flashlight/headlamp
Sewing Kit
Compass
Maps
Wallet/Passport
Matches/Lighter
Emergency Survival Wrap
Rubber bands
Soap
Toothbrush
Plastic newspaper bags
2 Water Bottles
1 Hot/Cold Thermos
Empty Gallon Jug
Pocketknife
Twine
2 feet of rope/clothesline
1 Foldable Spare tire
3 Spare Tubes
Cassette removal tool
All in one bike tool (wrenches, spoke tool, chain tool)
Rain cover for saddle
Tire levers/patch kit 

Pump
Electrical tape
Duct Tape
Spare spokes and Teflon Temp Spoke
Brake cable 

Derailleur cable 

Extra nuts, bolts, and wire (particularly for racks) 

Assorted plastic zip ties 

Small chain lube and rag

Patch kit