I know how hard the Long Way Up route is, so I was mystified when Ewan and Charley chose electric motorcycles. But was it more about plugging into the culture than the plug socket?

Riding a motorbike from Chile to Alaska is quite a challenge, I remember thinking as I bounced down the road in Colombia on my head.

So why Charley Boorman and Ewan McGregor decided to make Long Way Up even more difficult by using electric motorbikes was a mystery to me when they announced that their steeds of choice were going to be Harley LiveWires.

I rode the LiveWire prototype when it came out in 2015 as a concept bike, not for production. While it was an astonishing project from that most traditional of manufacturers, the range in economy mode was 53 miles, and in power mode 29 miles, or about the length of the forks on Peter Fonda’s chopper in Easy Rider.

It was a slick, sophisticated and exciting ride, but completely impractical.

But when Harley brought out a production version last year, I was astonished. With the power up from 74bhp to 105bhp, in sport mode it leapt forward like a starving greyhound after Bugs Bunny, reaching 60mph in 2.8 seconds and soaring on seamlessly to 115mph, all the while accompanied by a supersonic whoosh.

It was like riding one of the bikes that 1950s science fiction comics predicted we’d all be riding now and, on a more practical level, Harley claimed that the range was now a more acceptable 80-140 miles, depending on riding mode and level of hooliganism.

However, that’s not much use in the Atacama Desert. Riding a Triumph Tiger 955i with a range of up to 200 miles with careful riding, I was still running on fumes several times by the time I spotted a welcome petrol station in the shimmering distance.

So why on Earth did Charley and Ewan choose the Harleys for their ride from Ushuaia at the bottom of South America to Los Angeles?

As Charley said in a recent interview, the main reason was that after doing Long Way Around and Long Way Down on BMW GSs, they wanted to do something different. Ewan had already become an electric convert while living in LA, spending £30,000 converting his 1954 VW Beetle from petrol power. Which is about a grand more than the cost of buying a LiveWire, funnily enough.

“It’s the future,” as he put it in the Long Way Up trailer.

In the end, though, it looked like an exercise in making things difficult just for the sake of it, in the same way that they decided to ride through the bitter cold of the Patagonia winter and do long off-road sections for no obvious reason, since the roads in South and Central America are no worse than the ones in the UK.

But the main problem, as I’ve said above, was the range of the bikes, so they ended up running out of power – well, Charley says only Ewan did – and in the absence of fast chargers anywhere, they were forced to ask locals on the way if they could plug into their domestic sockets.

Friendly though the folks along that route are, their good nature must have been tested a bit by the dynamic duo, not to mention their back-up crew in two electric Rivian R1T pick-up trucks which also needed charging every 400 miles.

As Charley said, though, the good thing about it was that rather than filling up at petrol stations as they had on the previous adventures, they were plugging into people’s lives as much as their electric sockets. And meeting people, as much as the roads and the scenery, are really what adventures are about.

Particularly since, in an often divided world, it shows you that people are generally good everywhere, and that we have much more in common than anything that drives us apart – particularly when you crash in Colombia, as I did.

And that, whatever mode of transport you use, can only be a good thing.