When I went on the journey from KL to London, I had contingency plans for everything and that included the punctured tyres. I had my first puncture on the 4th day. And then another 7 times on that trip. It mostly happened to my front tyre, as it will yours, because the front tyre takes most of the pressure.
Rather than changing your tyre altogether, here’s a trick to make sure that poor deflated one gets back on the road.
The secret is to layer up. Thrifty as I had to be on that trip, I tried stocking up on supplies without spending a single cent. I went to motorbike shops where the mechanics who would throw out used tubes just outside their shop and picked a few pieces of used tubes that still looked unweathered. Get motor tubes because those are the thicker ones that will last you more trips.
An important step is to cut the tube to match the width of your tyre’s surface area that is in contact with the ground. Try to get it a tad wider, if all else fails. Once you’ve cut it to the right size, remove the tyre and place the used tube between the tyre and your bicycle’s inbuilt tube. Make sure that this is the surface area of the tyre that is in most contact with the ground.
Not my best work of illustration (haha) but you get the idea. Adding this extra layer within your tyre will save you a lot of trouble when the tyre thins out or if you run over sharp objects that could puncture it.
For my 18,000km, I inserted two layers each to both the front and rear wheels and I only brought 3 extra tubes and a tube patch-up repair kit with me. Every time my tyre was punctured, I changed the tube and repaired the damaged one overnight to reuse it for the next puncture. It was an average of 1 punctured tyre for every 2250km and if that counts for any experience in this, I would really recommend this safe and inexpensive precaution for your tyres.