400 KM Brevet - Gear that I Took

Wearing
Short Sleeve Base Layer
Short Sleeve Jersey
Arm Warmers
Pearl Izumi Shorts
Leg Warmers
Wool Socks
Cycling Gloves
Headband

In my Seat Bag
Crank Brothers Multi Tool
Two spare Tubes
Park Tire Boots
Park Spoke Wrench
CO2 Inflator with 4 Co2 cartridges
FibreFix Replacement Spoke
Reflective Sam Brown Sash (used after dark as per RUSA rules)

In my Top Tube Bag
Brevet Card (most important thing--no credit without this)
Cliff Bar (my bonk rations - didn't end up eating it though)
Jelly Belly Performance Jelly Beans (ate these about mile 50)
Extra Chamois Cream (used about mile 140 to reapply)
Extra Socks in a ziplock bag (did not use as my booties kept my feet dry)
Hand Warmers (didn't need, but with the cool temps, glad I had)
Extra Batteries for Lights

In my Jersey Pockets
Cycling Jacket (used the last 150 miles when it started raining and cooling off)
Full finger gloves (used in the second half of the ride)
Third Extra Tub
Hand Pump
Two packs of Gu (not used, but I never use Gu unless I'm in real trouble)
Cell Phone
Money Clip
Keys

Attached to my Bike
Extra Tire
Pearl Izumi Rain Booties in a ziplock bag (used these from Mile 97 on)

Comments and Thoughts
One of the difficult things about long brevets is all of the things you have to carry. This means bulk and weight, no other way around it. You about have to have three tubes for the distance you are going. Same with a spare tire. Weather complicates things. We encountered rain, so carrying rain gear was a must. But even if there is no rain, you will most likely be going significant night riding. And it cools off at night. So you have to bring things like leg warmers and a jacket, because 50 degrees at night is not very warm.

I didn't do a minimalist packing, but I didn't go crazy either. As it turns out, I could have left the hand warmers and extra socks at the hotel. But if it would have rained more, I probably would have been very happy to have those. I did not have any flats or mechanicals either, so I had no need or any of my spares. But you have to carry that stuff. It was good to have both sets of gloves. I used the normal set for the first 100 miles so I didn't feel overheated, and then switched to the full finger gloves later. My jacket is one of the bulkier items I carry, but you have to have it.

Is there anything I wish I would have had? Not really. A GPS, so we wouldn't have missed those turns, but that is something you attach to your bike, not something you carry with you.

That is what worked for me. Lots of other people have their lists out there for what to carry on a long brevet, but for now, that is mine.