You might think that Kevin Hart, the most successful stand-up comedian in the US, and Ice Cube, who produced Straight Outta Compton, the highest-grossing non-franchise film of the US summer blockbuster season, would resent spending a balmy Sunday morning in Los Angeles filming personalised messages to cinema audiences in London, Birmingham and Manchester, extolling the virtues of their buddy cop sequel, Ride Along 2. Hart and Cube do not see it that way. “You’re looking at two guys who are very adamant about wanting international success,” says Hart, who sits next to Ice Cube on a black leather couch deep in the bowels of a Hollywood photographic studio. “The one thing you’ve got to respect about the two guys sitting in front of you is that we’re not content. We’re both very successful in our own right, but we want more.”

Their Ride Along chemistry sets Cube’s trademark glower and scowl against Hart’s puppy-dog enthusiasm. Offscreen, Cube is affable and relaxed, while Hart tends towards the intense, focusing intently on questions directed at him, texting feverishly when not being addressed. That’s not the only difference between the two. Ice Cube was an overnight sensation – NWA achieved instant notoriety, his solo career took off immediately, the first film he acted in (1991’s Boyz N The Hood) was a hit, so was the first film he penned, the 1995 comedy, Friday. Hart is undeniably a powerhouse; he’s starred in seven films over the past two years, and his last stand-up tour played packed-out 70,000-seater stadiums. But his ubiquity is the result of a lengthy apprenticeship in the comedy trenches and a series of obstacles that would weaken the resolve of lesser men. His shot at network-sitcom stardom – 2004’s The Big House – was cancelled before a single episode aired. The same year, his debut film as leading man, Soul Plane, was widely bootlegged before its release, annihilating its box-office prospects.

I ask Hart if he envies Cube’s rapid rise. “We both have similar roads,” he responds. “It just took me longer. Mine was 19 years before I got to here. I’ve been doing stand-up since I was 18; I’m 36 now. I went through a world of rejection. My last four years have been the hot years. I’m more than capable of handling any level of success because I’ve handled the ultimate levels of failure. So now that I’m here, I’m motivated to stay here because I don’t want to go back to where I was.”

Hart’s stand-up show emulates rock concert extravagance. Pyrotechnics accompany his onstage entrance where he appears to burst forth from a video screen. Where once his stage persona was the diminutive (some have him at 5ft 4in), divorced dad frustrated by the world, now he’s closer to a comedic version of Thriller-era Michael Jackson. Bear with me here: Thriller was all about how unimaginable fame increased Jackson’s paranoia and fear. In Hart’s stadium act, he can’t go to the toilet without being followed and filmed by stalkerish fans; he can send his children to private schools but feels increasingly alienated by them; and his fancy house is terrorised by a raccoon that, he fantasises, will kill him.

Comics tend to struggle when their celebrity overshadows their connection with the audience. Steve Martin, Eddie Murphy, Adam Sandler and Jim Carrey all withdrew from live performances to concentrate on movies. Does Hart foresee a similar future? “None of this stuff happens without stand-up comedy,” he says, firmly. “If I turn my back on that, I feel like I’m doing a disservice to my fans.” Hart’s current prominence can be attributed to his tireless cultivation of a social media fanbase that now numbers 24.6 million Twitter followers and 28.3 million Instagram devotees. “I love the fact that I have the ability to say ‘no’ to certain things because of how strong this stand-up is. Regardless of the success of all these films, I’m never going to stop doing it. Even if I don’t do it on the scale I’m doing it now – arenas and stadiums – I’ll go and do comedy clubs.”

Photograph: Dan Tuffs

Ice Cube professes similar loyalty to rap. “The fans I had when I was first doing it are the same fans I have now. They still support the music. They’re just overlooked.” But a 25-year career as an actor, writer and producer who’s launched four successful film franchises (the Ride Alongs, the Fridays, the Barbershops and the Are We There Yets, the latter two of which were spun off into TV shows) is quite an achievement. Jean-Claude Van Damme didn’t manage 25 years, I tell him. Neither did Steven Seagal. “I think I have a stronger connection to my audience to these guys,” says Cube, grinning at the nonsensical comparison. “I understand what my audience is not getting from Hollywood and I try to supply it. I’m not a real jealous dude who has to have all the laughs or all the heroism or steal the scene. I’m about making sure that everyone’s great and the movie’s great.”

The first Ride Along, which grossed more than $150m at the global box office, fits smoothly into Cube’s catalogue of movies with endless watchability. He plays James Payton, a hard-nosed undercover cop who is forced to take his sister’s goofy security guard boyfriend (Hart) on a “ride along” as a bonding exercise. Soon the pair are infiltrating a Serbian smuggling ring, hurling themselves into explosive action scenes and riffing gleefully on buddy-cop comedy tropes. Ride Along unquestionably positions Cube as the straight man, a gruff, exasperated foil to Hart’s excitable naif. Does the sequel feature a more equal division of comedy? “We relied heavily on me as comic relief and Cube getting pissed off in Ride Along 1,” Hart agrees. “But in the second one, there’s moments where I take the back seat and let his humour drive the scene. There’s a see-saw. I understand what to do to make him funny. He understands how to make me funny.”

Both Hart and Cube are African American artists working at a time when black entertainment is making its most significant impact in mainstream America. In 2015, the hottest show on Broadway was Hamilton, the biggest hit on TV was Empire and, as previously mentioned, Straight Outta Compton was a monster. Are these individual success stories or are they harbingers of a greater change? Hart says: “The reason African American people are having success is that they’re getting the opportunity to put broad ideas on TV and in movies and ground them with the perspective of an African American mind. We’re showing it can have the same global reach and effect that anybody else can. I love the fact that these shows and movies are having this success because they’re no longer being looked at as black projects, they’re just good projects.”

Photograph: Quantrell D. Colbert

Cube continues: “Who knows if this is a trend or if it will fizzle out? I think Hollywood is realising that black people, especially here in America, go to movies. A lot of us don’t have these big home-theatre systems. We’ll see Star Wars and Minions but we want our own movies, too.”

Which leads me to the reason Hart and Cube were filming spots entreating UK cinemagoers to find room in their hearts for Ride Along 2. There’s a pernicious Hollywood belief that black movies don’t play in the rest of the world. Certainly, that’s true for Tyler Perry’s cross-dressing Christian farces, but it’s not a stigma that should be attached to more mainstream fare.

“Black movies don’t work overseas if you don’t advertise them,” says Cube. “Ride Along 1 and Straight Outta Compton did. I think we’re opening a market that shuts if you don’t keep feeding it. This is the same window that the Bad Boys movies had and that no one ever followed up on.”

“Give us the chance, don’t pigeonhole us,” demands Hart. “We’re willing to go on the plane, do the groundwork and build up that fanbase. If it doesn’t work, that’s your excuse to tell us ‘no’. Don’t tell us it doesn’t work when we haven’t had the chance. We don’t want to hear that shit.”

As the conversation winds down, I’m aware I’ve neglected to give the two men much of a chance to interact in a humorous fashion. So I ask Hart to list his top five rappers and Cube his five favourite comedians. Hart, who earlier called himself a student of rap, says. “You’re putting me on the spot because Cube’s here. I’m going to go Biggie. I’m going to go Hov. I’m going to go Tupac. I’m going to go Eminem.” He acts as though his final choice is a struggle before smiling across the couch. “My one West Coast pick is my co-star Ice Cube. You didn’t know how important Ice Cube was to NWA until he left and then you said: ‘Holy shit, that was the man behind the machine.’”

Photograph: Dan Tuffs for the Guide

OK, Ice Cube, name your top five comedians. “Eddie Murphy, Richard Pryor, Redd Foxx.” Without bothering to pretend he needs to think about it, Cube declares: “I love Kevin Hart, and Chris Tuck…” I halt him and point out that, as Hart picked Eminem, he’s obliged to name a white comic. The rapper once known as Amerikkka’s Most Wanted looks taken aback but, after a pause, volunteers: “Robin Williams – he made me laugh in Mork & Mindy.”

Hart grins at the amount of concentration Cube devoted to coming up with a white comic. “I think you can tell there’s more than mutual respect between us. Yes, we’re both the stars of the movie, but I’ve learned so much from the guy. It’s a great relationship.”

Cube reciprocates the sudden outpouring of affection. “I know Kevin’s sitting here but he’s changed the game. He’s taken stand-up to a level I didn’t think anyone could take it to, a level bigger than Eddie Murphy. I just think this dude here is the most clever one of them all, and he’s still so normal.” He can’t resist puncturing the warm moment with a sidelong smirk. “But one day I’m going to see him walking around with a leather jacket on and the collar turned up, not looking at anyone and his handshake will be like a piece of cotton. I’ll be like: ‘Damn, he finally drank the Kool-Aid.’”

Ride Along 2 is in cinemas on Friday