Pirie, who is 50 but says he feels 21, swapped Grangemouth for Goa to set up Nomadic Knights which offers tours across the subcontinent.
He was inspired to visit in 2006 by his father who rode army bikes in the Scots Guards in India after the Second World War, and was blown away by the country's beauty. The trip made him question his life in Scotland and he returned in 2010 and fell in love with an Indian woman. They married two years later and live next to a 22km beach. He calls his new life "paradise".
Pirie, a trained mechanic, says: "India is amazing, hundreds of different cultures, languages, traditions and food. It has glorious beaches on the Arabian Sea and the Himalayas in the north. It has rain forest in the north east and vast deserts in the west. It has everything that would suit an adventurous biker."
He operates trips using 500cc Royal Enfield Bullets across south India, the Himalayas, Assam, Nagaland, Rajasthan and is planning a trip from Kathmandu to Everest base camp in Tibet.
He says: "The Bullet is a great bike. I have always had motorbikes since I was young. Yamaha FS1E, Yamaha RD250, through to GSXR1000, R1, Ducati 999R, and various dirt bikes.
"Riding the Bullet is a very different experience. It's only 23bhp however once you master the smooth and progressive riding style it requires it makes you 10 times the rider you were if you are used to superbikes. With superbikes everything is instant, power and brakes. The Enfield has none of that so you learn to ride with a greater sense of awareness.
"My bikes are all specially prepared with bigger fuel tanks, different wheel rims, seats, handlebars and exhausts. I also run two different fleets of bikes, battle green colour for the north and diamond white for south India and Rajasthan. They are immaculate and look fantastic. Most companies here run standard bikes however I wanted to offer the riders something unique and give them a very special riding experience."
The Scot, who works with the Adventure Ashram charity, says safety is his no1 priority and the trips are supported with a doctor, mechanics, support vehicles and drivers with Pirie as team leader. He says the riders have ranged from 18 years old to one who is 84 years old and has done five trips.
The trips vary in price from £1800 up to £2800 and include everything except flights.
Pirie, a former personal sponsor of TT rider Keith Amor, says: "There have been so many memorable incidents from people falling off on the very first day, to being stuck up in the mountains for three days due to landslides. When these things happen we all pull together as one big team and work our way through it.
"One of the funniest incidents was when a client took not well and decided he didn't want to continue and his insurance company instructed him to take a taxi back to a hotel 400kms away. The driver stopped during the night for food and the client got out to stretch his legs. The driver got back in and didn't notice that he wasn't there. It wasn't until the driver got to the hotel hours later that he noticed he was missing. The insurance company, with our help, found him three days later in a remote village being well looked after by the local tribal people. He said that he enjoyed the whole experience and was much more of an adventure than he had anticipated. He took it all in good spirits.
"The trips are very much about taking yourself out of your comfort zone and taking on new challenges. If you are a pipe and slippers man then they are not for you. If you like the challenge of riding ten hours across the desert or riding the worlds highest road at over three miles high then you will love them."