Take a look inside your wardrobe. How many items will still be in there ten years from now? And of those, how many will actually look better, fit better, be worth more than you paid for them, fulfil a vital practical function and work as a stylish design classic? None? Then you clearly haven’t been spending enough time in an exclusive store off London’s Regent Street, the home of a jacket that has barely changed in more than 50 years but has nonetheless progressed from mere protection for motorcyclists to the musthave accessory for film stars, supermodels and selfrespecting off-duty bikers everywhere.

We’re talking about the Belstaff Trialmaster wax motorcycle jacket. In a world that has come to revere vintage fashion, it would be hard to find a more fitting leader of the vintage pack, principally because secondhand models change hands for huge amounts of cash.

Like a fine wine, it actually improves with age – so the more worn and battered the better. It’s why Che Guevara, Steve McQueen, Angelina Jolie, the Dalai Lama, Kate Moss, Naomi Campbell and George Clooney have all proudly owned one, and why you’ll have seen them in hundreds of movie moments – most recently Batman Begins, The Aviator and Four Brothers – and why thousands of amateur and professional motorcyclists insist on nothing less.

As if its rugged aesthetic appeal wasn’t enough to treasure, it’s even got a ritual attached to it.

Because buying a Trialmaster is just the beginning – to preserve its water resistance, once a year it needs to be anointed, in a certain way, with a special substance unique to, and provided by, Belstaff. Indeed, there is only one way to kill a Trialmaster – sticking it in the wash or handing it to a dry cleaners. If you don’t invest time and care in it, you won’t get anything back.

No wonder men love it; though the appeal goes further, too. As Naomi Campbell told us, ‘The Trialmaster is such a sexy, iconic design. I’ve had one for years – it’s so warm and comfy and fits like a second skin. And there’s a real sense of history to it. It’s a triumph of British design – and so practical. There’s no doubt it’s the coolest, best-looking biker jacket in the business.’ George Clooney is no less keen: ‘I’m an enthusiastic biker, and I’ve always worn Belstaff jackets. I ride every day – I think nothing of sitting on my Harley for eight hours riding from Lake Como to Rome. Belstaff actually asked me if I wanted to do a campaign for them, which suited me fine – I got paid for it, which helps when I do movies that don’t make much money…’ Like so many style classics, the Belstaff Trialmaster has humble origins. In 1924, Harry Grosberg and his father-in-law Eli Belovitch started making a modest range of waterproof apparel in Stoke-on-Trent, Staffordshire.

Given Britain’s climate, they rapidly found a demand for their sturdily constructed wares. It was, however, their move into manufacturing motorcycle clothing three years later that assured them the holy grail of ‘brand definition’. In 1930, the Belstaff Manufacturing Company was formed, taking its name from Belovitch and Staffordshire.

Twenty years later the famous Trialmaster was born. It became an instant hit with bikers, who had grown to trust Belstaff’s craftsmanship. They also bought it because of three revolutionary design details: pivotal armholes for better forward rotation, precurved sleeves for improved fit and comfort during riding and, most importantly, a showerproof lining to stop the wax coating penetrating the inside of the jacket. The company also insisted on quality Egyptian cotton – and so a masterpiece was born that has managed to straddle the gap between utility and chic.

George Clooney is no less keen: ‘I’m an enthusiastic biker, and I’ve always worn Belstaff jackets.”

Things have moved on a bit since then – in 1991, motorcycle designer Franco Malenotti and his two sons bought Belstaff’s licence, before taking control of the company in 2004. One of Franco’s sons, Manuele, has no doubt what makes the Trialmaster so sought-after. ‘It’s a classic item that appeals to people from all walks of life,’ he says. ‘Put simply, you could wear the jacket over a designer suit and it would not look unusual.’ The Trialmaster is far from Manuele’s only jacket.

The Belstaff range is vast – at the chichi Conduit Street store, leather jackets are knocked out at prices of up to [pounds sterling]819 (for an Aviator sheepskin jacket), and his particular favourites are the Roadmaster Classic and the Panther. But, he says, ‘I understand the fascination with the Trialmaster.

It’s interesting to see vintage ones becoming collectors’ items.’ The foundation of the design is wax cotton.

Maritime tradition saw it being used to protect sailors and dockers from harsh weather. Belstaff, in a shrewd move to work with materials that had proven their worth under rigorous testing, and in the process saving themselves research and development investment, decided to go back to basics.

The cotton is coated with oils that render it waterproof without compromising its wearability, comfort and shape. Wax cotton of the Fifties was heavier and therefore harder-wearing and far more water-resistant than it is today. But at least these days the lighter compound is less greasy and smelly – veteran Trialmaster wearers will regale you with tales of how their loved ones would ban old jackets from entering the house.

To keep it in top condition takes dedication. The yearly re-waterproofing is recommended; and besides, knowing that Steve McQueen may have declined an early night with Ali McGraw in order to re-wax his Trialmaster makes the ritual all the more worthwhile.

And ritual it most certainly is. First you must hold the jacket next to a source of heat, then warm the special compound supplied by Belstaff in a bain-marie.

You then evenly – very important – oil the jacket with a clean cloth and leave for several hours near the heat source. You then liberate the jacket to the fresh air for a couple more hours.

Of course, all the design technology and waxing in the world would amount to nothing if the jacket didn’t look good. According to Belstaff, its Black Prince jacket, which dates from 1943, is ‘the best-selling waterproof jacket of all time’. But the Trialmaster pips it to the post in Belstaff’s sartorial range.

A phoenix-like motif is underscored with the eternally cool bold Helvetica font, the rustic gold thread adding that final dash of elan.

The four outer pockets make it a practical garment, but it’s the angle of the two chest pockets that sets it apart stylistically. The trajectory gives the look of armour, which is complemented by the shoulder and elbow patches.

If you choose to tie the belt, the torso is defined; many wearers decide to double-tie the belt, leaving a looser fit and a slight taper at the back.

The Trialmaster boasts four badges. Two Belstaff idents on the arms, one on the right-hand chest pocket and a Union flag under the left-hand chest pocket.

And finally, there’s the integrally belted Mandarin collar – the icing on the cake. If the jacket were to have any other collar, it would throw the aesthetic balance.

Like all the greats, the Belstaff logo is simple and unmistakeable. A phoenix-like motif is underscored with the eternally cool bold Helvetica font, the rustic gold thread adding that final dash of elan.

Manuele has a theory about the jacket’s longevity and its iconic status.

‘The Trialmaster has a timeless look. It’s got that retro feel, but it’s never going to fall in and out of fashion, purely because it’s a one of a kind. It’s above fashion.’ There are two options when buying a Trialmaster.

Either search the web for dealers willing to part with a vintage model (they regularly attend bike meets – visit first4gear.com/bikemeet.html to find your nearest), or go and buy a new version from Belstaff’s flagship store on Conduit Street,London

Finally: which bike will sir be wearing with that?