This picture shows Chris cutting up a coke can with a knife, trying to make a soda can stove. It was a complete fail. We had brought our trusty MSR multi-fuel stove to western China, thinking it's ability to accept petrol, or kerosene, or diesel, would mean we were fine for fuel. We stocked up with food in Urumqi, the capital of Xinjiang province, and went to the first petrol station we saw after cycling out of the city. The dark-haired man shook his head emphatically when we mimed filling up our fuel bottle at the petrol pump. "Maybe they're out of petrol?" Chris said. We tried the next petrol station. And the one after that. Until, at the last place we tried, Chris was physically pushed out of the store by the attendant.

What was going on? Surely all the petrol stations hadn't run out of fuel? And, if they had, why would the attendants be so upset we were asking to buy some? It was 2011 and accessing data in a foreign country cost $10 a megabyte. I took the plunge, turned data back on and discovered it is illegal to sell fuel to anyone without a car in western China. Presumably to prevent people making molotov cocktails – in 2009, Urumqi was locked down by the Chinese government for 6 months because Uighur factions had killed a number of Han Chinese. There were riots, which the Han suppressed by use of military force and breaking down communications – cell phone, internet, and satellite communications were precipitately shut off and all landlines were monitored.

I used additional data to search for solutions to the no fuel problem, coming up with the soda can stove concept. That was $20 down the drain. We spent the rest of our cycle from Urumqi to Yining hiding in trees and shrublands and making fires with minimal smoke. Our challenge was, it was illegal for foreigners to stay anywhere other than a tourist hotel in China, and there was no tourist hotel in the Tian Shan mountains along the 700km between the two cities. All was well that ended well – we didn't carted off by the police and we had an amazing cycle ride. However, I desperately wished for a medical alcohol stove which I could have brought, if only I'd known .

Preparing for Mongolia is much easier than Xinjiang was. There's more information available online. There are more products available online. We spent hours agonising over how many litres of carrying capacity we need and how we can carry food for five days and water for at least two days. Over time, we have honed our gear and bags to a streamlined level of minimalism as shown below. Unfortunately, minimalism doesn't mesh well with multiple days without resupplies. Our conclusion, of likely interest only to keen bikepackers, was a lightweight rear rack (rather than an underseat tail bag) with a large dry bag on top and cages on the stays in which we can put water or fuel bottles. We will increase our carrying capacity by around 15 litres, or 40% more volume. What's that going to be like to pedal...we will discover :(

As much as I might like to scoff at consumer culture, I'd have to admit to enjoying the process. We pulled our gear out, iteratively trialled in it the bags we already own, searched online, rang the keen bikepacker who sold us our Bombtrack bicycles, searched online some more, then purchased an Old Man Mountain Elkhorn rack (based on our positive experience with Old Man Mountain shipping a new rack to Kyrgystan after my rack fell apart in the Pamirs) together with some King Cage Manything Cages because titanium cages are cool (and light) and cherry-coloured Ortleib rolltop drybags because our similar front roll bags have lasted nearly a decade of hard use.

Another part of the food dilemma, beyond being able to carry enough, is how little is available in rural Mongolia. According to bikepackers' reports, the only surety is being able to purchase pasta and potatoes and cheese so hard it breaks your teeth. We thought about taking freeze-dried meals from New Zealand – these have become the default for many outdoor sports people given their light weight, good flavours and the simplicity of heating water, pouring it into a bag, waiting 15 minutes then eating dinner. However, they are very bulky - there's no way we could fit 5 weeks of meals of the size pictured below in our expanded bags. Not to mention, that would be a lot of weight. The obvious solution is to take vegetables, which are not available in Mongolia, and use them to supplement the carbohydrate we will be able to buy. However, New Zealand freeze-drying companies sell mostly whole meals and only a pea-bean-corn mix in small bags as a vegetable option.

Enter...the prepper market. There are a plethora of online shops operating in the UK and the USA selling a wide range of freeze-dried supplies, both meals and ingredients (if you are stuck in a bunker for a good portion of eternity, you might want variety in your meals and you'd have plenty of time to be creative). Prepper shops sell freeze-dried vegetables, and fruit, and cheese.  Impressively, the stores sell large tins of freeze-dry with a guaranteed twenty-five year life. Do you think reconstituted scrambled eggs with cheese tastes the same at year twenty-five as it did at year one? Of course, in a doomsday event, who is going to chase the supplier for a refund?