It's really not about the bike

It's really not about the bike, but you might be interested in the trusty steed:

 

Frameset:

• Frame & forks: Orro Gold Disc STC frameset - full carbon, solid, but not particularly light in XL size!  I wanted a standard 1 1/8" stem, 27.2mm seatpost, and quick release wheels, rather than thru-axles, so I could reuse components I already own.  However, there are other lighter framesets which I'm eyeing-up for the future...

Transmission:

• Di2 mechs: Dura Ace 9070 11 speed front & rear mechs with internal battery - to allow charging on the move, with a light, USB-powered battery charger
• Di2 shifters: Shimano SW-R671 Di2 bar end shifter & the addition of a SW-R600 Di2 climber switch - to compensate for my current poor hand strength
• Cranks & cassette: SRAM Red BB30 110bcd crankset with Extralite 50t & TA Specialites 33t chainrings, with Stages carbon left crank arm, SRAM Red 11-28 cassette, Carbonice chain catcher - this combination gives me a grovel gear of 33x28 which is very useful for spinning up long mountain climbs and reducing the strain on knees and back.  50x11 is big enough for the flat and descents.  The Stages power meter allows me to pace at the right wattage for the terrain
• Chain: KMC X11SL DLC chain - light, smooth and durable, I do like KMC chains.

Braking:

• Levers & calipers: R785 Di2 hydraulic disc brake STIs & RS805 flat mount disc brake calipers
• Rotors: Alligator Stealth 140mm rotors - light but plenty durable.

 Wheels:

• Wheels: Extralite CyberFront & CyberRear SPD wheelset with Ryde Comp Pulse disc rims - very light @1160g, very robust build
• Quick Release skewers: Not really "quick", Tune Skyline skewers are really light and also have a dedicated tool for removing them, which makes your wheels harder to pinch
• Tyres & Tubes: Continental GP 4000 IIS 700c x 25mm tyres & Planet X Superlight tubes - zero punctures in thousands of miles, I hope my current greatest fear is realised if I puncture and have to change a tube with my crippled hands!

Steering & Finishing kit:

• Bars & Stem: Haero carbon H.155 bars with Extralite HyperStem - I created my own ultra-comfortable composite pads from a combination of EVA and memory foam, welded together with Araldite.  EVA foam gives a good amount of rigidity, whilst the memory foam gives softness and flexibility, all wrapped in heavy-duty, waterproof gaffer tape, to stop water soaking in
• Saddle & Seatpost: Tune Speedneedle saddle, Carbonice 27.2mm seatpost - for flexibility and comfort.  It might not look it, but the Speedneedle saddle is the best, most comfortable I've ever ridden
• Pedals: Speedplay Zero Nanogram pedals - picked-up very cheaply, brand new from eBay!  Very light, I wouldn't change my Speedplay pedals for the world as they have the best surface area contact between cleat and pedal

Other kit:

• Electronics: Garmin 1000 Explore - the Edge version was more expensive, didn't have maps, but had loads of "training" functions which I've never bothered to use.  I much prefer the rubber waterproofing seal, as well as the bigger screen, to the Garmin 810, which I've had two deaths in service.  Top tip to double battery life - turn off the Bluetooth!  I'd like to carry a Garmin Virb or GoPro, but the battery life and added complications for power sources, as well as weight, makes this a no-no
• Clothing: Assos, Assos, Assos - jersey, cap and Uno shorts - I wouldn't ever change from Assos shorts' pads, they really are the best for your botty!  For Hard Cro I'll be using Giro LTZ time trial gloves for their lack of padding, as I need to protect my hands from sunburn, and don't want bunching to cause sore hands.
• Helmet: POC Aero helmet - to keep the bugs out and the rain/wind off my head.  The normal Gemini helmet mount for the light head unit only fits helmets with two holes.  My POC Aero only has one hole, so I removed the base of the light, drilled a hole in the top of the helmet, and mounted the light with one washer inside and outside the helmet.  1g direct helmet mount - a 15g saving!
• Waterproofs: Gore-Tex Active One GTX - limited edition, ultra-breathable and ultra-light @99g, I got this as a bargain from Evanscycles.  It works brilliantly as a windproof, too.  Assos SturmNuss HK 3/4 length, Sealskinz socks, Velotoze overshoes, Gore-Tex Xenon gloves - all hardy kit, I haven't yet tested the Gore-Tex gloves but they'll surely be excellent.
• Front & Helmet lights: Gemini Xera 800 & 950 lights - 50g head unit, powered either by a custom 6xAA pack, or dedicated light battery packs
• Rear light: Cateye TL-LD1100 - powered by 2x AA batteries, the battery life is 100-odd hours.  I didn't change them for the duration of the Giro, and had them on for most of the race
• Hydration: Osprey 3L bladder - worked really well in the Giro, except for a slow leak on day 5, holds as much as 6x bidons, so is good for those times of night (or day) when there's nowhere you can source water.  I put SiS Go for the carbohydrate and electrolyte content, as well as Whey protein powder and Glutamine, to minimise muscle degradation
• Bags: Alpkit custom frame bag, top tube bag, 2x stem bags - the custom frame bag doesn't fit exactly, as I had it made for my Giant Defy Advanced SL (which got run over and written-off in April), but fits well enough and has enormous capacity.  Enough to carry the Osprey 3L bladder, food, tools, spares, clothes, and more.  The top tube bag carries electronics, batteries, money, whilst the stem bags will be used as extra capacity, solely for food and drink.  All Alpkit bags are water resistant.

Electronic shifting
I do absolutely love electronic shifting, which is vastly superior to mechanical shifting due to greater accuracy, faster shifting, and lower maintenance.  No cable snapping problems, just use an internal battery and carry the internal battery charger for rides over 100 hours, just in case (Di2 batteries are reckoned to last 200 hours), or take an additional external battery.  Di2 shifters are much easier on your hands, requiring only a light touch of the buttons, rather than a big push of the levers.  I'm curious about SRAM Red eTap, but SRAM are only just releasing a hydraulic disc brake option, so it's not really an option at the moment.

Hydraulic braking
"I didn't have any brakes" said the riders who descended various hills/mountains in the torrential rain, at the Giro, using traditional rim brakes.  They got so scared that they stopped.  I was concerned about the rivers in the road and being unfamiliar with the descent, but I kept going.  Disc brakes have excellent stopping power, especially pronounced in the wet, and reduced hand and forearm strain for those switchbacked mountain descents.  Both electronic shifting and hydraulic disc brakes are noticeably superior for ultra distances for the minimal effort required to shift or brake.  If I get desperate, I can remove a hot rotor and use it as a shuriken to defend myself against bears and wolves.

Bike packing
I've had a lot of questions as to whether crosswinds blow you more when you're carrying a frame bag.  It doesn't, at all.  I think this is because of the turbulence which your legs create on both sides of the frame bag.  Top tube bags, being placed behind the stem, are also aerodynamically positioned.  If there were any drag, it's not noticeable - we're not doing 30mph 10mi TT, this is ultra-endurance!  I do like the new style of bike packing bags, as panniers are heavy, un-aerodynamic, and look naff.  I don't want to look like a tourer, either, so, similarly I'm not growing a beard.  I can't grow a beard anyway.  Cyclo-touriste look is definitely out for me.  I'm not using a saddle pack because they're hard to get stuff out of and, when they're moderately heavy, they tend to waggle the whole bike, especially out of the saddle.  Not a nice feeling.  A bit like having a child seat or panniers mounted.  See above.

Weight Weenie
Am I a weight weenie?  No, but I don't see the point in carrying extra weight which you really don't need to.  You're just making yourself go slower.  I changed some of the bolts on my bike, to standardise them to 4 hex/Torx bits, rather than 8 - life is just simpler.  Another example, the classic argument of carbon vs titanium frame, "titanium is more comfortable and robust" - both are comfortable and robust, with loads of testing.  The only reason a carbon frame would break is if you crashed it, in which case your race is over.  And you could be dead already, so who cares?  A titanium frame would be broken in the same scenario.  And you'd be dead in the same scenario.  Similarly with lightweight components, these aren't Chinese-bought knock-offs, they've been through rigorous testing in Italy, Germany, etc, so why wouldn't you trust it?  Does it really have to be over-engineered (ie: heavy) so you feel it's safe?  It's just an emotive, perception thing - don't get hung-up by it, just go ride it and don't give into the fear of the unknown.