The first thing on Andrew Rogerson’s to-do list when when he lands in Seattle on Saturday morning is seek out a shop that sells bear spray.

The 33-year-old engineer isn’t in search of a quirky souvenir from his trip to America. He’s getting ready to embark on a 3,100 mile cycle from the west coast to New Jersey in 42 days, which will take him right through the middle of bear country. 

When we speak on the phone three days before his departure from his home in Liverpool, he is far from ready. “I haven’t packed yet, to be honest, it’s a bit manic round here,” he says with a glimmer of apprehension and the confidence of a man whose done this all before. 

It was on his last trip in 2015 when he cycled 10,000 miles from Shanghai to UK, on a route that took him through 19 countries, that Rogerson first acquired the affectionate moniker, “the cycling scouser”. 

He helped to raise around £50,000, for his colleague’s son Charlie, 12, who has been battling leukaemia for nine years and needs money for international treatment, and Rogerson sees this upcoming challenge as the second leg of that first trip.

Although this is the second innings, there are several parts of the first trip he is less than keen to repeat. Like when he was held at gunpoint in Turkey, or when he was followed by a pack of wild dogs in the Kobi desert for over two hours. “This story is not going to go down well with the RSCPA but I was just filling my bag with rocks and getting ready to throw them,” he laughs. “They had eyes on me as their next meal.”

This time round his biggest concern will still be the wildlife – the bears and mountain lions that roam the mountain ranges. “There was a cyclist just weeks ago who was mauled to death and his friend was seriously injured. [Two mountain bikers were riding the Cascade Mountain trail near Seattle when they were attacked on 20 May. Only one survived]. I’ve just got to go that way, there’s no choice,” he adds. 

Once he is through the Rocky Mountains, which stretch some 3,000 miles from British Columbia and Alberta in Canada through Idaho, Montana, Wyoming, Colorado and down to New Mexico in the U.S, his next biggest challenge is the distances he needs to cover every day.

A self-proclaimed early riser, Rogerson will wake at 4.30am to be on the road at half past five (before sunrise) and get three hours of cycling under his belt before his first break. In order to reach a minimum distance of 100 miles per day, he allows himself pitstops of only twenty minutes before resuming for another three hour-long stint.

“As long as Charlie is fighting his battle I feel as though getting back on the bike is the least I can do,” he says. “Even though the last ride was longer, I think this one is going to be more of a challenge. I’ll be covering daily distances much larger than the last ride and I’m definitely not built for speed!”

In order to reduce his weight, Rogerson will be attempting to travel with as little baggage as possible. Although without a support team or vehicle, he will have to carry his own tent and camping stove, as well as a few changes of clothes and a drone for recording video footage of the ride.

For food, he’ll need to stop at service stations. “I’m not a big fan of American food to be honest. Just everything is covered in cheese,” he laughs. But it is nothing compared to the rationing he has endured on previous trips, like when he crossed the desert in Turkmenistan in 58 degree heat.

Does he get lonely? “There’s no time to get lonely and with social media I am constantly in contact. I’ve been in the desert for days before without seeing anyone, I’ll be fine.” Although he says that his girlfriend and family do worry.

But for Rogerson, it is all worth it to help Charlie, his father Robert and their family. “It is just human instinct to want to help them, you could just see Robert’s heart was breaking every day he had to come to work to pay for his family. Now we want to help.”

Determined to add to the funds already raised (Rogerson’s colleagues are also doing their own fundraising and have reached a total of around £300,000 between them) this probably won’t be his last cycle. “My family and friends knew what they were getting into when I signed up for this,” he says.