One of the most common questions I get about bikepacking and endurance races like the Arizona Trail 300 is how you can carry everything you need. The answer, which I've come to after generous input from others and lots of trial and error, is a combination of lightweight gear, packs that fit your bike, and miserly packing. The products below aren't everything that I use, nor will they work for everyone. I know guys that run dramatically different setups than mine, and every race calls for a different set of gear. But I've found the following items reliable and indispensible over lots of trips into the backcountry.
Depending on how rough a course is, I choose between a full-suspension 29er like this Specialized Epic 29er or my tried-and-true Moots Mooto X YBB. Stiff wheels are a must for handling the big loads (I love the Easton EC90 XC 29"), and thru-axles on front and back help, too. Fully loaded for the AZT, my rig weighs 34 pounds, including 5,000 calories and one full water bottle.
Garmin eTrex 20 ($200) Though I love Garmin's cycle-specific units, for endurance events nothing beats the rugged eTrex. Unlike internal, rechargeable battery-powered units, the eTrex runs on AA batteries so you'll never be left stranded (just bring spares batteries). It has a data card slot for adding base maps and all screens and fields are customizable. Though I've had some bugginess with the stopwatch function and how it records tracks, I fully expect that to be rectified with firmware updates. And while the joystick navigation is a bit fiddly compared to a touchscreen, that's a small price for durability and certainty.
Revelate Designs and Salsa Cycles frame packs ($55-$150) Getting cargo weight off your body and onto your bike will keep you fresher. Revelate's Viscacha seatbag holds up to 14 liters, is totally impervious to the elements, and doesn't buck around even on techy trails (though it may rub on some full-suspension designs). Revelate used to sew custom-size fame bags to fit in a bike's main triangle, but they've gotten out of that business and are now sewing packs tailored to Salsa's El Mariachi, Mukluk, and Spearfish frames. These are as durable and well-thought-out as the company's custom offerings. Check the sizing because they fit a wide range of current bike designs. And I always run a top tube-mounted Revelate Gas Tank for quick access to food.
Stoic Somnus 30 Sleeping Bag ($300) For sheer weight-to-warmth ratio, I haven't found anything better than this down and pertex bag. At just 1 pound 6 ounces, it compresses smaller than a nerf football but has kept me warm on many a cold high Rockies autumn night. Together with pad and bivy sack (see below), my sleep kit weighs just 2 pounds 10 ounces and straps neatly to my bars in a six-liter telescoping compression sack.
Inertia X Frame ($100) This bizarre-looking inflatable pad puts insulation where you need it (head, shoulders, hips, and feet) and saves weight where you don't. It's surprisingly comfortable for back-sleepers like me and has proven more durable than all other superlight options I've tried. I use it on top of a space blanket ground cloth or tuck it in my sleeping bag, both for puncture protection and to keep it in place.
Mont-Bell UL Sleeping Bag Cover ($175) Built of two-layer GoreTex with fully taped seams, this seven-ounce bivy packs down smaller than a Tallboy but provides lots of minimalist protection. Combined with the Stoic Somnus 30, it has kept me warm and dry in an all-night drubbing of rain at 11,000 feet on the Colorado Trail. If the forecast is warm and dry, often this is all I carry for sleep provisions.
Fenix Lights PD31 ($70) These tough little flashlights from Asia throw a huge amount of light (304 lumens) and run off batteries for distance trail events. Many racers prefer the LD series, such as the LD-22 (190 lumens), because the AA batteries that power them are more widely available than the CR123 that power the PD lights. But I prefer the extra brightness. If an event is likely to last three nights or less, I often opt for the much brigher Lupine Betty 6, which you can program anywhere between 1 and 2600 lumens. On one 10-ounce battery, I can get 21 hours at 420 lumens.
MSR HyperFlow Microfilter ($100) This is my big splurge in weight and space. Many racers make due with iodine or other chemical water treatments, but having grown up in Africa bad water makes me squeamish and I always carry this pump. At eight ounces and about the size of a medium banana, it's not all that bulky and I appreciate the certainty of always being prepared to hydrate.
Ergon GS2 Carbon Grips ($100) I almost cannot ride a bike without these ergonomic grips anymore. The flat sections take a ton of weight off your arms and eliminate hotspots in your hands. After using these for years, I rode a three-day event without them and had buzzing and tingling fingers for weeks. Ergon has models without bar ends, but I appreciate the variety of positions over the long haul. This redesigned GS2 has softer rubber than previous models for even more bump damping.
Osprey Stratos 24 ($100) Normally I carry the svelte Raptor 18 as I like the multiple pockets and organizational features, but the AZT has a particular set of demands. After the 300, I plan to carry on at touring pace along the entire AZTR course (750 miles), which traverses the Grand Canyon. Because bike tires can't touch dirt in this national park, it's necessary to break down your bike, strap it on your pack, and hoof it rim to rim. The Stratos 24 has a very sturdy frame system for this size pack, and after field-testing carrying capacity on many packs, this one feels the best for both riding 750 miles as well as hefting an awkward 40 pounds. The pack plus my kit weighs around 11 pounds, including 100 ounces of water.