Seán, who is a member of the EvoPro Racing team, was left with fractured bones in two different vertebrae and four broken ribs.
He said if he had landed a couple of centimetres in another direction, he could have damaged his spinal cord.
When his dad went to investigate the location, at Townley Hall woods, county Louth, he found a length of rope placed between two trees suggesting that the ‘trap’ had been reset.
It happened on July 22 and Seán said.
“I was only after coming home from Belgium on Wednesday, from road racing with my team, EvoPro racing, it is the only Irish professional men's team.
“I came home to ride (in) the mountain biking all-Ireland championships on Sunday. I wanted to do a bit of training on the Friday on the mountain bike to get used to the bike again before the race,” he said.
“I went over to Townley Hall, as I have hundreds of times before. I went around pretty much all of the trails and then I got myself going in a little loop up at the top of the trails.”
He was about three quarters of the way through his session.
“I came around the same section of a trail I had been on maybe five-10 times already that day.
"It was a straight line and all of a sudden I went over the handlebars and found myself on my back.
“I had landed on top of a tree stump and straight away I was in agony.”
He thought initially that he was winded but when he sat up, he knew he was hurt.
“I realised there was something really wrong. I stood up and could not straighten my back and I had this horrible pain in my side in my back.”
He managed to get his bike up off the ground and rolled on it through the woods to the main road and rang his father who then called for an ambulance.
He struggled to breath and when the ambulance came, after about 20 minutes, he was given oxygen and morphine.
“I suffered four broken ribs, two fractured bones in two different vertebrae, T11 and T12.
"It was so close, only a couple of centimetres to my left, (and) instead of breaking the little bones at the side of the vertebrae, I could have damaged my spinal cord but thank god I didn’t. I also had a partially collapsed lung.”
Asked if he thought it was possible he could have ended up paralysed, he said, “yes, it was a real possibility.”
He initially thought a branch had caught in his handlebars but if it had, he says he would not have fallen as he did.
When his father went to the location Seán described and found the rope and showed it to Seán, he said, “it made perfect sense. If it was just a branch that had caught my handlebars, I would have been able to hold it (bike) up.”
Seán said that having done the loop a number of times before it happened it seems like maybe someone had been watching him and had just decided to put this trap up.
“IIt is only speculation, but it seems like there is not much more of an explanation than that,” he said.
“Obviously the person who did this wanted to cause some harm. You do not put a rope or a wire up across a trail that is known to be used by mountain bikers.”
He does not believe that the rope was put there by children or people playing with ropes.
He said: “The way it was put up was in a perfect place to cause damage on a straight (stretch) , where you would be up to speed.”
He did see adults walking at the popular location, but not children.
Asked if his feeling is that this was a trap, he said “yes.”
His message to anyone who sees a rope or wire across a trail in a forest, whether they are a walker or a biker, is, “please think of the safety of the people who might be using the trail.
"If you see something like that, please take it down because you do not know who is going to unexpectedly come around the corner and come off a lot worse than me.
“I can only imagine if it was a child and they came off worse than me or if it was an old person enjoying their cycle. I would encourage people if they could try to take it down. You can blatantly see it could cause injury.”
A spokesperson for Coillte said it does not operate or authorise any mountain biking trails at Townley Hall.
Sean said, what happened to him “could have as easily happened to a walker. It could have injured someone badly,” adding, “there is a deep history of mountain biking in Townley Hall for years.”
The spokesperson for Coillte said: “Coillte is aware of an incident involving a mountain biker in our forest at Townley Hall over the weekend and an investigation into the incident is currently underway.
“Townley Hall is a very popular recreational forest for locals and visitors to the area.
"Coillte do not operate or authorise any mountain biking trails at Townley Hall.”
The spokesperson said: “For any activity other than walking in our forests a licence must first be obtained.
"The primary purpose of the licence is to ensure the activity can take place safely and enjoyably with the safety of all the users of our forests at the centre of the process.
"Coillte has no licensed mountain bike activity in our forest at Townley Hall.”
Seán said gardaí from Drogheda have called to him and ‘they are pursuing an investigation.’
The Garda Press Office said: “Gardaí received a report of an incident involving a cyclist at Townley Hall Woods in Drogheda Co Louth on the 22nd July 2022. The cyclist was taken to Our Lady of Lourdes Hospital to be treated for non-life threatening injuries.”