reading through the list only a couple things I might recommend that might not have been mentioned or might be unconventional. These are not part of the standard core stuff that might be on everyone's list or might just not have been mentioned.
1) hand/foot warmers... just added them to my kit for the first time ever.... not sure what I think, but they may mean the difference between fun riding and some extremely uncomfortable feet on a ride.
1.5) neosporine... carry it in my kit year round, alternative to chamois creame with many more uses.
2) toilet paper... good fore multiple obvious things, but also a great fire starter
3) swedish fire steel... actually more reliable then lighters, and ironically... at least with above toilet paper torn into strips, just as easy to use as a lighter
4) bacardi 151... lol... only partially kidding... i sometimes carry when winter touring in a Platypus Reserve bladder. If you're going to carry alcohol bacardi 151 is superb for fire starting. Also good in tea by the fire in the evening.
Alternately you could switch to Heet or other gasline antifreeze, but that's not edible.
5) wind breaker/raincoat... I carry some type of wind breaker every ride I go out on, that's just standard equipment. My favorite is a 4-5 oz O2 Rainwear jacket, but when touring I carry the lightest Frogg Togg Dri Ducks jacket because it can actually fit over my down jacket
6) down jacket... if you're way in remote places
7) a bubble compass or other compass... probably mentioned above
cashews or other high energy food... some mentioned Gu above... same difference, whatever you prefer, Gu is probably easier to metabolize
9) a good fixed blade knife... I prefer fixed for baton use, sometimes everything is wet and you need fire, firesticks, splitting wood to get at heart wood
10) PVC rain pants... an emergency piece of gear... freezing rain is a killer... also great if you need to sit around in the snow.
I must admit most of the above is touring related. There is much more need for overnighters. Perhaps I should full on list my overnighter/ s24o kit.
== emergency warmth ==
So... there's a larger issue. I admit I like to ride all night sometimes. Nothing like riding with a full moon reflecting off the snow and lighting the night up like day. Don't know why, just love it. Below is the problem though.
On a recent trip I decided to try a power nap at about 3:30-4am. Try to cool down slowly. Put on my extra sock layers, spare merino wool base layer and PVC over pants, down jacket over my fleece jacket and base layers... even my Frogg Togg Driducks rain jacket. Extra hat. It was probably about 25 degrees.
Did actually manage about 15-25 minutes sleep. But the thing I realized is if I became incapacitated, i.e. slipped on some ice and busted a knee, there was no way I was going to make it long without a sleeping bag and an air mat. There's just no way to keep warm. At least not without getting drastic and hacking up some trees, getting some pine boughs to lay on and starting a fire.
I did btw, have insulated matts which I was using to sit on, but short of breaking out the sleeping bag there's just no stopping for any extended period out in the cold.
So, I guess I'm wondering how ultraracers hunker down in the cold. I.E. on the iditarod... is there such thing as a "power nap" or do you just have to full on break out the whole kit? I guess I'm just looking to perfect my ride all day and all night without fear.
BTW, favorite place to stop on tour after riding all night... all night laundromat or early morning laundromat.
It's great to show up in a new town at 6-7am and open up a bakery or breakfast joint, then head over to a laundromat, throw in a load of laundry, set the alarm for 45 minutes or so, power nap, throw clothes in the dryer and then another power nap. By then I'm usually good to go for the day until evening. Eventually I do have to catch up on sleep though. Full on start a fire, set up the tent and break out all the winter camping gear if it's below freezing.... or on occasion get a hotel room and crash hard.
Am working hard on making my kit more slacker friendly / easier to setup and pack-up, but it's so much easier in the fall. Down bag in the bivy, don't even need anything more then an Autoshade for insulation or mat. Means I can be asleep in minutes after stopping and rolling again just as quick. However it has a use threshold of about 32 degrees. Below that we're talking some sort of tent and perhaps a full airmat. i.e. my stripped down shangrila 3 and big agnes insulated air core.
My motto... if you're not sleeping well, then you haven't been riding hard enough or long enough.
Also been thinking of a new definition for ultra-endurance dirtbags... rides dirt all day, lays down in the dirt at night, gets up in the morning, brushes off some dirt and does it all again. Hammockers might disagree.