When did it all start to go downhill for mountain biking?

The Tour de France is about to visit the UK amid an English-speaking cycling boom – much as it did 20 years ago. But, despite the success of Chris Boardman and Sean Yates back in 1994 – both of whom wore the leader's yellow jersey during that year's race – the boom then had little to do with road-cycling, and everything to do with the then-fashionably rugged mountain bike. From TV to Sunday supplements, mountain biking was the public face of cycling, and the coolest hobby of the year.

Two decades on, the wheels have turned: road-cycling is at its pinnacle, and the mountain bike is a memory long since buried at the back of your shed. So what went wrong?

In 1994, the Tour swept past me almost unnoticed. After investing the money I'd saved from two years of washing neighbours' cars each weekend, I'd become a paid-up mountain-bike bandwagon jumper – and one of the first things you learnt as a mountain-biker was that roadies were miserable skinflints who liked rules more than they liked having fun. Being 14, I hated rules, liked fun, and loved mountain-biking.

That year, Lloyd Grace opened the bike shop Top Banana in Woodford Green, directly on the route of this year's Tour De France stage three, which goes from Cambridge to London. With Epping Forest on its doorstep, Top Banana gained a reputation as one of London's best mountain-bike shops, and its weekly rides became the stuff of legend.

"During the 1990s we stocked 90 per cent mountain bikes," Grace says now. "We didn't really do road; back then, a roadie was a very different person to roadies now. They were old-school, they didn't want to spend money."

The 1990s were an exciting time in the world of mountain-biking. Since the 1980s, the bikes had all looked much the same – skinny steel tubes, fat tyres, cantilever brakes and a few gears. But by the time 1994 rolled around, suspension forks were beginning to appear, rear suspension was becoming more than a pipe dream, and new materials, such as carbon fibre, aluminium and titanium, were being employed to make bikes lighter, stronger, stiffer – and more desirable. I can't imagine I was the only one who filled the margins of my school books with doodles, aping the style of "Mint Sauce", the hand-drawn comic strip chronicling the life of an MTB-mad sheep on the South Downs, as seen in mountain-biking's then-bible, MBUK magazine.

"Back then it was seen as more of a fun thing," says Grace, "and when Trek and Fisher brought out the [full-suspension] Y-bike, that got a whole new bunch of people into it. It didn't look like a bicycle any more, it looked futuristic, and that really changed sales – everyone wanted one to hang off their car, to have in their garage or just to ride down the street."

Looking back, that point may well have been the beginning of the end for mountain-biking. Over the past 20 years, it has progressed from offering very few options to far too many in an ever-increasing number of niches – there's a choice of three wheel sizes with suspension travel ranging from zero to 200mm, covering sub-genres from cross-country to enduro and all-mountain to downhill. Where do you start?

"Are we making bikes that are way too niche and technical for people? Should we be going back towards simpler bikes?" asks Carlton Reid, editor of the bicycle-industry magazine BikeBiz, and himself a member of the British team that competed in the first Mountain Bike World Championships in 1987. "Mountain-biking has been a victim of its own success," he believes. "It got popular quickly, diversified and created lots of product. For new blood, that much choice is stultifying. It's a hidden cult now – people used to get into mountain-biking because it was an accessible form of cycling. It's not any more."

The term "mountain bike" itself has never been helpful – the French term "vélo tout terrain" seems a better description. Top Banana built a community of mountain bikers by leading rides around Epping Forest, the highest point of which is a full 91m above sea-level. Top Banana closed its doors in 2002, the death knell being sounded by the combination of a wet summer and the outbreak of foot-and-mouth disease in 2001. "You couldn't ride, you couldn't race, there were land closures; it just killed us," says Grace.

Since that time, the public image of mountain-biking has morphed into an extreme sport, all about young men throwing themselves off cliffs or down ravines. It's a frustrating misrepresentation, when for most of us, a mountain-bike ride looks much the same as a road-ride – riding along with friends, talking and enjoying the countryside, but in the woods or on the Dales, away from the constant, dull threat of motorists. And the bike you need to do that really isn't very complicated – a rigid frame with a suspension fork is the most economical entry point, and many will see little point progressing beyond that.

Yet, while mountain-biking may not be attracting new people to the sport in the way road-cycling currently is, it is a powerful tourist industry; last year, Tourism Intelligence Scotland stated that mountain-biking visitors were worth £119m to the country in a tourist economy worth a total of £4.3bn. That's a significant sum, particularly to the rural communities mountain-bikers favour.

I've always seen mountain-biking as a supremely practical means of getting to places you'd never normally be able to access. So when the Tour comes to the UK this July, I'll be chasing the race on my mountain bike, using bridleways and by-ways to get between viewing spots and avoiding the inevitable congestion that will snarl up the surrounding roads.

Twenty years ago, it was unimaginable that Britain would produce two consecutive Tour winners, or that road bikes would ever again dominate the leisure cycling market. But things change. Amid the hoopla of the Tour's visit this summer, it's worth remembering that long before we rediscovered the peculiar pleasure of chasing tarmac, there was, and forever will be, the mountain bike.

Andy Waterman is the former editor of the mountain-bike magazine 'Privateer'. He also organises the mid-week mountain bike-race series Beastway at the Olympic Velopark in east London (beastwaymtb.com)