So, here’s my thinking – fit a HD inner tube before starting the trip to minimise punctures. I couldn’t believe how much bigger the HD tube is. Here is one next to a normal tube. It’s massive.

My concerns now are how it will affect the handling of the bike with so much extra centrifugal force on the wheel. Also I think I’ve read somewhere that the HD tube is harder to repair. I had planned on fitting the new inner tube when I fitted new tires just before the start of the trip, but that means I won’t get any chance to see how the handling is affected. I guess I’ll just give it a go and if it doesn’t work I’ll swap it for one of the two spares (normal size) tubes I intend to take along.