The plan is for tourists to ride side-by-side tandem bikes through what Mr Main believes is the country's best railway track scenery particularly north of Wairoa through the "Whareratas".
He believes it could see 600 people pedalling various parts of the track each week, with a potential to boost visitor nights in Wairoa by 30,000 a year - more than 50 per cent up on the figure for last year.
Of necessity, it would be all one-way traffic, north to south, with four one-day segments: Gisborne-Opoutama, Opoutama-Wairoa, Wairoa-Putorino and Putorino-Esk Valley.
Tourists could opt for one-day adventures, costing about $120 per person, up to four days, one segment at a time, for a cost of over $400.
To start from the Esk Valley end would impose an immediate uphill battle which would see most of the 30-plus target age group adventurers lucky to see out the first day.
Mr Main discussed plans being put in to address numerous safety issues, and plans to build 200 of the rail-bikes once he gets a green light, which he says KiwiRail may be withholding pending consideration of consortium plans to run freight trains on the line.
He believes the chances of the iron horse opening up the east again are, however, inhibited by the cost of repairs at the washout which closed the Gisborne-Wairoa segment of the line in 2011.
Repairs can be made at a much lower cost to accommodate the much lighter-framed four-wheel transporters, of which he hopes to have 200 built in Gisborne and which he says will provide a unique tourism experience, unlike any other experience in the world.
He says he's tested the market for potential users and looked at an already track-leased operation between Stratford and Ohura - where golf carts run on an otherwise mothballed rail line through 20 tunnels in a limited-season venture run by farmer Ian Balme.
"It all hinges on the access," he said. "The catch phrase is this isn't the closing of the line - this is the opening of the line."