Welp. Here’s a master list I use when going on a trip where I’ll be renting a bike. I adjust as appropriate for the actual trip. I never rented a helmet, but helmets are washable, so if considering renting one, you can wash it first.
Cycling clothing
□ Jerseys
□ Shorts
□ Legs
□ Socks
□ Jacket
□ Rain jacket
□ Skull cap
□ Gloves (short / long)
□ Helmet
□ Helmet cover
□ Bike glasses
□ Mirrors
Bike stuff
□ Water bottles
□ GPS/computer: (load area maps) mounts, cable, charger
□ Bike tool
□ Tire patches
□ Shoes / Pedals
□ Saddle
□ Cable lock
□ Chamois butter
□ Bike lights
Equipment and spares
□ Zip ties, duct tape, vinyl tape
□ Tape measure
Clothes
□ Underwear
□ Socks
□ Shirts / Tie
□ Pants
□ Shorts / Swimsuit
□ Belt
□ Shoes / sandals / flip-flops
□ Sweater / Fleece
□ Coat / Jacket / Windbreaker
□ Sun hat
□ Bandana
Travel Accessories
□ Cell, cable, charger
□ Bose headphones
□ Seat cushion (tail bone)
□ Camera, cable, charger
□ USB Charger
□ Electrical adapters
□ Sunglasses and retainer strap
□ Spare glasses
□ Sunblock and lip balm
□ Insect repellent
□ Hand sanitizer gel
□ Toiletries / Razor, charger
□ Butt wipes
□ Personal first-aid kit
□ Aspirin, Ibuprofen, Benadryl
□ Prescription drugs
□ Vitamins
□ Watch
□ Flashlight, headlight
□ Books / Magazines
□ Pad pen
□ Snacks and drink mixes
□ Ziploc baggies
□ Travel pillow
□ Ear plugs
□ Clothes line
□ Wash cloth
□ Umbrella
□ Plastic bags
Luggage
□ Duffel bag or soft suitcase
□ Luggage tags and luggage locks
□ Security wallet/money belt
□ Backpack
Official Papers
□ Wallet, insurance cards, contact info
□ Itineraries, Maps, Reservations, Insurance docs
□ Valid passport
□ Airline tickets
□ Copies of docs
□ Business cards
□ Log-ons and phone numbers