The romance and endless possibilities of a motorcycle create many an armchair adventurer. But if you’ve got the bike, the time and the yen for “Zen and the Art of Motorcycle Maintenance,” why not think big?

“Long Way Up” is the third epic motorcycle trip/travelogue undertaken by avid cyclists and longtime actor friends Ewan McGregor and Charley Boorman.

After “Long Way Round” (2004) took them around the world, across Europe, Siberia and North America, and “Long Way Down” (2007) saw them venture from Scotland to South Africa, they figured they’d never get around to one last super-long trip.

McGregor told me as much when I interviewed him as his film “Salmon Fishing in Yemen” came out, back in 2011.

But circumstances changed, McGregor’s family life blew-up thanks to a very public affair with a co-star, and his turn in “Fargo” — where he met said co-star — gave him the luxury of another months-long odyssey. So he and Boorman, fresh off a couple of hospital-stays due to bike accidents, took a pre-Pandemic ramble from Tierra del Fuego, on the bottom tip of South America, to Los Angeles, where McGregor now makes his home.

Such a trip killed Classic “Top Gear,” but Boorman and McGregor are such charmers you can’t imagine a Jeremy Clarkson-style international Argentine incident, complete with BBC coverup, this time round.

For their latest “Long Way,” the lads would be riding American metal — Harley-Davidson motorcycles, with Detroit-built custom trucks hauling the support team. The hook? The Harleys are electric prototypes, and the trucks are Rivian electric pick-ups.

This ride, with two 50ish dads, would be about the adventure, the scenery, meeting and sampling new cultures and new cuisines. As always. But it’d also be about the greener future. And part of the adventure would be the added degree of difficulty steering electric vehicles through corners of the world where they haven’t caught on and installed charging stations.

No wheelies and vigorous off-roading for the lads. Their 100-150 mile range bikes would turn them into hyper-milers.

In the dozen years since their African trek, tiny GoPro style cameras on helmets and tiny camera drones have become all the rage. The footage is a lot more varied, lots of aerial shots. And the quiet electric bikes mean they can chat at-will while riding.

They’re always ooohing and aaaahhhing over the scenery, the states of the roads, glaciers and penguins, llamas and deserts, rainforests and volcanoes of Costa Rica and Nicaragua. Occasionally, the dire state of their battery range dominates the conversation.

Ewan even sings and plays the guitar he buys en route — “Oh we’re ridin’ on a bike that doesn’t take no gas…I got the border blues, the border blues.”

“Long Way Up” shows us their “steep learning curve,” coping with battery range issues in the bitter cold southern South American winter, figuring out recharging in places where their support companies — Harley and Rivian — didn’t get charging stations installed (and they installed quite a few along the way), charming closed out-of-season hotels and hostels into reopening, it’s basically a nostalgic revisiting of the earlier quests’ Greatest Hits.

A Ewan McGregor movie is showing in one pub they stop in. There’s even a Chilean family that takes them in and feeds Charlie and Ewan, who mistakenly thought their house was an electronics business. That’s the first place somebody “makes” Ewan.

“La Isla,” the man says (“The Island”), in Spanish to his family, recognizing the star. Good thing Ewan’s Spanish is pretty bad at that stage of the trip. Reminding an actor of an infamous bomb isn’t good form — in Scotland, anyway.

Mobbed in Machu Picchu, and Ecuador, McGregor reminds us he’s a good sport.

National parks, seaside drives, deserts crossed, a UNICEF children’s shelter in Nicaragua — they even find themselves using local guides to dodge gang activity and “keep a low profile” in in Guatemala and Mexico.

It’s just that “Everybody that wants a selfie lets the world know where we are,” McGregor shrugs.

Many episodes and incidents remind one of why it takes a good-sized support team to undertake “Zen and the Art of Motorcycle Maintenance” on the “Blue Highways” of the less-developed world. A backup generator truck when the local power supply fails, an advance team to hold a ferry here and there, they even buy buses to fix up and use as campers for “night-driving” in dangerous Guatemala and Mexico.

The “Dad joke” nature of the trip slyly sneaks in here and there. Suffering the aftereffects of spicy food, Ewan, running his bike until the juice is gone — repeatedly, at first — Charley horsing around, just a wee bit, even though he’s coming off two bad accidents and long recoveries. Their epic adventure on bikes is more sweetly nostalgic this time round.

McGregor is much more the center of this trek, with Boorman more in the background. But the changes in McGregor’s personal life aren’t addressed in the least, which considering the “family” focus of the first two, leaves that as an elephant in the room. This isn’t “that kind” of friendship. No buddy bonding on-camera confessionals, or even fake ones of the type Steve Coogan and Rob Brydon serve up in their “The Trip” movies.

The arrival of McGregor’s adopted Mongolian daughter for part of a journey seems like a desperate and obvious effort to address that gap without doing anything of the sort. For a while, at least, his other kids wanted nothing to do with him.

Still, it’s a lovely travelogue – 13 countries worth. Hyper-miling to do it with electric bikes adds bits of suspense and touches of drama.

For those of us who can do math, noting how few miles they’re able to pile up in the bitter winter cold of southern South America, 13,000 miles in 100 days does start to seem like a ride-too-far.

But that’s a reason to stick around to the end, isn’t it?

MPAA Rating: TV-PG

Cast: Ewan McGregor, Charley Boorman.

Credits: Directed by David Alexanian and Russ Malkin. An Apple TV+ release (premiering Sept. 18)

Running time: 11 episodes @45 minutes each.