1. Flip-up aero bars -- Provides new riding postures including efficient positions for hill climbing and headwinds. Also, it gives a zero-force, non-gripping hand position.
2. Granny gear -- 24 teeth in the front and 34 in the back. I use it on most hills of any size. If I could go lower next time, I will.
3. Mirror -- How did I get along without one for so many years? A quick glance in the mirror gives important information about traffic coming up from behind.
4. Gatorade -- I never used sports drinks until last summer's trip. Now I am hooked. The sugar and salt content seems to keep muscles nourished longer than juice or milk, and the fat content takes the edge off of hunger. Interestingly, the moment my trip ended, I stopped drinking it, and have not a drop since. But I will definitely take it on my next trip.
5. Fenders -- What was I thinking by not installing fenders on my bike 25 years ago???