Hypnotised by a long line of red lights and a sudden feeling of being totally alone in the darkness were surreal sensations I experienced as I took on the challenge of the Dunwich Dynamo last weekend.

I’d read a few personal accounts of this 120-mile blast through the Essex and Suffolk countryside but nothing really prepares you for the ride that starts in the fading light of East London.

A sea of cyclists greeted you as you arrive in London Fields – a mix of serious lycra together with quite a few souls in regular clothes who look as if they were popping down the shops for a pint of milk rather than an overnight ride to the coast. The park was also still busy with people out enjoying the warm weather with the thermometer still hovering around 25C. Though the event has been running for 24 years a couple of bemused onlookers asked me “what the hell is going on”.

“This is NOT a race”, screams the first line of a sheet of A4 directions handed to me by one of the organisers. And without any fanfare, at 8pm, legions got on their bikes by the Pub on the Park. My intentions of grabbing a big bowl of pasta before the start were soon forgotten as I joined the throng making its way through the narrow confines of Martello Street bike path.

The procession through Hackney was not everyone’s idea of fun though the sheer number of cycles was enough to stave off even the most impatient motorists.

East London quickly turned into suburban Essex and the scrum of cyclists had already turned into a single file. The sun was already set by the time we reached the Wake Arms roundabout though I assured my two cycling buddies that there would be plenty of options for pasta and coffee in Epping – noble intentions that ended up as pork pies and cans of Coke from Londis…

I’d never cycled beyond Epping – unknown roads even harder to navigate in the darkness. Familiar names started to flash past: Moreton, Fyfield, Leaden Roding and the 32-mile point Great Dunmow. Pockets of villagers screamed encouragement at cyclists including a four-person handbuilt contraption, tandems and one brave cyclist who’d brought his child along in a trailer.

We stopped for a pint in Great Bardfield at 43 miles; locals joining in the party atmosphere as cyclists either stopped or pedalled on. Although just gone midnight conversations seemed to hover over the fast pace of the tour, probably helped by the fine weather and almost constant light westerly breeze. Finchingfield, Wethersfield, Sible and Castle Hedingham then passed in quick succession before we reached the halfway point at Sudbury about 1am where huge queues had formed for coffee and a barbeque put on by the local fire crews.

Though the temperature never fell below 16C over the entire event tiredness was now starting to set in but before we got too ensconced in our chairs we decided to push on.

It was this part of the event where groups of cyclists started to spread out though, because most were cycling at roughly the same speed, you started to notice the same people: the guy in the Heinz baked beans top, the group cycling for Alzheimers, the guy with the kiddie trailer (again) comes into view, the child still awake and appearing to be transfixed by a tablet. I exchanged pleasantries with a guy in a top with the dragon of Wales emblazoned on the back – inane conversations though most seem happy to just get their heads down and eat up a few more miles.

It was around Bildeston that the roads suddenly seemed to turn really dark. Pedalling on I focus on the line of red lights in the distance – almost hynotised by the rhythm of the whole thing – but then suddenly realised that I was cycling downhill at roughly the same speed as I would in daylight. I turned my head to find that my two cycling buddies were nowhere to be seen, and neither were any other riders. An overwhelming feeling of being alone suddenly dawned on me and I eased back on the pedals though it was a good 10 minutes before my companions catch up – one asked just what exactly was in the muesli bars that I had been munching away on for six hours.

At 3am the delirium started to set in: the University Challenge theme tune was going on a loop in my head – a couple of cyclists that have brought along loud speakers failed to distract me. Our charge to the coast was eventually interrupted by a puncture, my cycling buddy exclaiming in the darkness: “This wheel doesn’t feel right!”.

By 4am the sky had long begun to lighten and the fading batteries of many riders’ headlamps was no longer such a pressing issue. I think it was around Sibton Lake that pop-up cafes started to emerge at the side of the road. Alas, the long queues prevented us from stopping, so terrified were we that if we stopped for too long our bodies would cease up. No matter. Many other cyclists by now were beginning to stop and rest on verges; a few oblivious that the sun was beginning to rise as quick as they were falling into a slumber.

The last 10 miles from Framlingham, once the sun had risen, seemed to be the hardest. I’m not sure if it was my brain being unable to cope with the additional distraction of having to deal with looking at beautiful countryside. And a couple more inclines seemed to be the last straw for a few cyclists who got off and walked.

The pine scrub of Minsmere spread out after passing through Darsham before our ultimate destination Dunwich, the Lost City, ended our odyssey. After 10-and-a-half hours we’d done it.