Eesh, picture 3 would give me pause about running a narrower tire at lower pressure. Even the smoother-looking hardpacked portions can have potholes that blast you. And more than a few times I’ve done a gravel event where the town had recently put down a fresh layer of crushed rock that hadn’t packed in yet.
But I’m not here to tell you to not do the event, or that you have to buy another bike (although…). My suggestions:
- Figure out what’s the biggest tire you can run on your frame, on your rims. Note that what you can run up front may well be different from what you can run in the back.
- Go tubeless, if your rims are made for it.
- Go for tires with some puncture protection – I’ve had great experience with WTB tires. If you can get a set of Byways (700x34) in your frame, that would be my choice, but if that’s too wide consider an Exposure (700x32) or Expanse (700x30).
- Learn–and practice–sealing up punctures in a tubeless tire quickly. (See my thread looking for feedback on different tools for this)
- Don’t be afraid to run with your bike through sketchy sections. It’s faster than riding 100 feet and having to fix a puncture. And a hell of a lot faster than walking home.
Good luck