Me, me mum, me dad and me gran, we're off to Waterloo,
Me, me mum, me dad and me gran, with a bucket of Vindaloo

Why this? Of all the disposable nonsense that sits dormant under the safety blanket of my conscious mind, why this? I'm two thirds up the Col du Tourmalet, cycling along the highest road in the central Pyrenees, and all my broken brain can think of is some God-awful parody of a bad football chant.

Or, more exactly, two lines from some God-awful parody of a bad football chant. I've stopped trying to remember what comes next. It's a memory I appear not to possess. Instead, those two lines are playing on repeat in my head.

Me, me mum, me dad and me gran, over and once again.

^{Lesson number one: never look up during a mountain ride (PIC: Rufus Exton / Le Coq Sportif)}

I'm surrounded by cyclists, all struggling up this monstrous mountain pass at their own pace. Everyone has trained for months to be here, to take part in the annual Etape du Tour, when thousands of amateurs get to cycle an official stage of the Tour de France. We're pedalling along the same 146km route that the pros will plough just days later, starting in the town of Pau, riding up and down the Tourmalet, and finishing atop the ski resort of Hautacam. The scene around me feels like a monumental occasion, the combination of huge individual efforts to achieve one shared goal.

But it's eerily quiet. The weather has extinguished any excitable chatter left in our lungs. Three hours earlier, we left the start line in Pau just as clouds were gathering overhead; 90km on and we've climbed up to meet them. Visibility is terrible, the air is wet to touch, it's getting colder with every metre of ascent – and we still haven't broken the back of this sodden mountain. All I I can hear is the insistent panting of people. And Fat Les.

Me, me mum, me dad and me gran, with a target of Hautacam.

^{The profile of Stage 18: Pau to Hautacam}

The 2115m summit of the Col de Tourmalet is famous among cyclists as one of the Tour de France's 'hors catégorie' – meaning 'exceptional' or 'unclassified' – climbs. While it's not the highest in France (other mountain passes near 3000m), the climb has featured more times in the annual road race than any other major mountain, thanks in part to its steep final section where the average gradient reaches a vertiginous 10pc.

It's the kind of mountain where Tours are won or lost. You only have to look back to 2010 to see the Tourmalet in Tour-defining action, when Alberto Contador and Andy Schleck locked horns on their way up the climb in a mountain-goat-to-mountain-goat battle that quickly passed into cycling legend (only to earn one of those history-dampening astorixes after the former's positive test for doping).

This year, Vincenzo Nibali will be hoping to defend his yellow jersey on the way up to the top of the pass. If recent ascents on the Tour are a good indicator, Nibali and co will climb from the village of Sainte Marie de Campan (at 668m above sea level) to the top of the Tourmalet in under 55 minutes, having already raced 17 times in the preceding 19 days.

I crest the mountain 1hr, 31 minutes, and 46 seconds after leaving Campan, with fire-filled muscles and a mind that appears to be embracing insanity. Endurance sport is supposed to be reflective, even meditative: constant exertion and endorphin releases tranquillise the mind, setting it free to wander. But rather than finding transcendence, mine has wandered straight down an earworm cul-de-sac. I just can't shake that refrain.

Me, me mum, me dad and me gran, we're on the Tourmalet.

'Tour' in French means 'trip' and 'mal' is bad, so 'Col du Tourmalet' can be translated as the 'Mountain of the Bad Trip'. That's a slightly disingenuous rendering: the Tourmalet is in the Gascony region of France, where the local dialect mixes Occitan and Basque influences, so a more accurate translation is 'The Long Mountain'. But 'bad trip' exactly describes what I'm experiencing. In fact, it's so bad it features Keith Allen.

Me, me mum, me dad and me gran, with a head full of Vindaloo.

^{Heavy rain makes the descent treacherous (PIC: Rufus Exton / Le Coq Sportif)}

The descent brings the world back into focus. It's now raining heavily and the temperature has dropped close to freezing. As the road winds down the west side of the Tourmalet in a series of switchbacks, my arms start shaking. Then the muscles that connect my neck go solid and immobile. I can't turn my head – but it's my fingers that are my real worry. They are quickly going numb, which means it's difficult to tell how hard I'm squeezing the brake.

The following 20km of riding down to the village of Luz-Saint-Sauveur is the scariest thing I have done in my adult life. The shaking spreads from my arms up into my shoulders as my body gets colder; I'm desperate to turn my legs over to generate warmth, but I'm too fearful of the speed it would create. Slipping off the road would mean plunging down a dramatic drop. Two ambulances rush past me, sirens wailing. I can taste my own mortality in my mouth.

^{Note the scrunched up fingers and facial gurning (PIC: Rufus Exton / Le Coq Sportif)}

At Luz-Saint-Sauveur, I get off my bike, desperately stuff cake and an SiS energy bar into my mouth to give my body fuel to burn, and do star jumps to try to get my blood flowing again. Around me, cyclists are being helped off their bikes and wrapped in the insulating silver foil that you see at disaster scenes in the movies. I notice one man ride into the food station with a blue bottom lip.

I later learn that I'd been lucky. 13,000 people started the Etape du Tour this year, but only 8,452 finished. The weather got worse as the day went on, which meant that those who had started later than me had to cycle for much longer in the wet. Many got to the top of the Tourmalet and immediately gave up to seek refuge in a café while waiting for a coach to drive them down; others got off their bikes on the way up to take shelter in the caravans of spectators who lined the roads.

^{Spectators at the foot of the Hautacam (PIC: Rufus Exton / Le Coq Sportif)}

As I ride on and near the ascent to Hautacam, those spectators provide easily the best moment of the day. Riding along a long valley between the two mountains has warmed my body, and my mind has finally moved on from its Vindaloo obsession. I'm feeling good, so I pass the final feed station and turn right to begin the last climb. The scene at the end of the corner is like the Tour itself. I'm enveloped by throngs of cheering spectators, who crowd along the road, leaving only a narrow path to navigate. I feel like Contador and Shleck, like Chris Froome, Bradley Wiggins, Bernard Hinault and Eddy Merckx. It doesn't matter that I'm travelling at roughly half their pace and that most of the spectators are probably in town to see the real thing fly through a few days later; I am, momentarily, the King of the Mountain.

Another hour and twenty minutes of brutally steep climbing later and I feel about as far away from regal as you can imagine. I cross the finish line over 7 hours after leaving Pau, having been passed by more people than I care to recall on the way up to Hautacam. I come in just over 3,000th place, but I have no idea whether that means I've done well or not. All I know is that I'm grateful I've finished. And that, during the final kilometres of the climb, I remembered the next line to that God-awful refrain.

Vindaloo, Vindaloo, Vindaloo, Vindaloo, na na
Tourmalet, Hautacam, Tourmalet, Hautacam, na na...

^{Peak pain: Jonny Cooper seconds after finishing the Etape (PIC: Rufus Exton / Le Coq Sportif)}

Cycling with the right gear

Bike: Raleigh Revenio Carbon 3. A bike designed for long days in the saddle. The large cassette on the back wheel allows you to spin easy gears during the climbs. £1,900
Jersey: Le Coq Sportif Etape du Tour Jersey. £65
Jacket: Le Coq Sportif Montech Windbreaker. £175
Bib: X-Bionic Bike Bib Tight Light. £159.99
Helmet: Louis Garneau Edge Helmet. £62.99
Sunglasses: Bolle 6th Sense. £139.50
Nutrition: There are food and drink stops along the route, offering energy-rich sustenance. It's also worth cycling with your own supply of carbohydrate to keep the body constantly fuelled: I ate five SiS Energy Gels and two SiS Energy Bars during the seven hours I was on the bike.

Le Coq Sportif is the official partner of the Etape du Tour. To sign up for next year's event, keep an eye on letapedutour.com