It's tough to walk the line between weight and preparedness, but in the middle of nowhere I'll take a few extra ounces of prevention. I run a Rohloff, so I don't pack a spare jockey wheel or Stein tool, but I do for long trips on my derailleur bikes. Also, none of my bikes have suspension outside the tires, so I don't pack a shock pump. Having a way to remove the pedals is nice for long hike-a-bikes or bushwacking. Below is what I carried on the GDMBR, which is basically the same kit I carry on most of my trips.
Leatherman Rebar multi-tool – carried on my belt and used for everything from food prep to opening faucets without handles.
15mm wrench for the Rohloff axle bolts and pedal removal
8mm / 10mm combo wrench – the two most used sizes
T-20 Torx wrench for Rohloff bolts
Crank Brothers Multi 19 tool – great chain breaker and spoke wrench
Plastic Shimano Hollowtech II tool for the outer crank arm bolt - I've used this a lot for bottom bracket adjustment and repair
Fiber Spokes – I carry two
Replacement spokes – two front and two rear with nipples, stored in my handlebar
Spare shifter cable - the Rohloff uses a slightly smaller ferrule but it's easy to modify a standard cable with a file.
King Cage titanium tire levers – light and strong
Generic patch kit
Presta to Schrader valve adapter – for touring I use Schrader valve tubes
2 extra tubes – Schrader valve
A few miscellaneous nuts, bolts and washers
2 chainring bolts that also double as Rohloff disk rotor bolts.
A few chain links and a master link
Front and rear disk brake pads - I leave these out for trips under 2 weeks
Gorilla Tape – the strongest duct tape I have found
Tyvek tape– for fabric repair
Zip ties
Small tube of Aquaseal
Small sewing kit – thick nylon thread, one straight and one curved needle, 2 safety pins and that’s about it.
2 hose clamps
3 feet of baling wire – there’s a reason why farmers fix everything with this stuff
Lezyne Micro Drive HV pump with gauge – the best pump I’ve found for high volume tires
Chain lube, an old toothbrush with a chopped handle, and a rag
I store all of this in a zippered stuff sack which is kept in a seam sealed Tyvek envelope to keep it waterproof. If you're interested, the rest of my pack list can be found at
http://wanderingbybicycle.com/gear-list-for-the-great-divide-mountain-bike-route-gdr/