The Borders Buses service follows successful trials between the capital and Peebles this summer.
The operator has increased the number of its buses with two internal bike racks from four to ten, which are due to further increase to 20 by February.
Four of the buses are on the firm’s 253 service between Berwick and Edinburgh via Dunbar and Haddington, which it said made the route “Scotland’s first fully bike friendly bus service”.
The West Coast Motors-owned company’s other bike buses will run on its X95 Carlisle to Edinburgh via Hawick and Galashiels service, and its X62 service from Galashiels to Edinburgh via Peebles.
All vehicles on the X62 route will have bike racks by February, making it the company's second full bike bus route.
Borders Buses said all of the new buses it ordered would also have bike racks.
The £3.25 million move comes after the operator introduced its first three bike buses - later increased to four - on the route to the mountain biking mecca of Peebles in April.
Transport secretary Michael Matheson said: “This is a welcome investment from Borders Buses and the West Coast Motors Group, supporting our ambition to build an active nation having recognised and responded to customer demand.
“This innovative step will encourage joined up and sustainable everyday journeys using both bikes and buses – improving our air quality and reducing congestion by creating new reasons to leave the car at home.”
Jim Densham, campaigns and policy manager for Scotland for lobby group Cycling UK, said: “We’re delighted Borders Buses is leading the way on bike-friendly bus routes in Scotland.
"The success of their pilot shows how much people value public transport options where they can take their bike on board.
"Especially in rural areas, it’s really important people can use cycling as part of their journey, and therefore leave the car at home.
"It also allows people to cycle as much as they want, knowing there’s a bus as back up for part of the journey or to return home.
"We now look forward to other bus companies in Scotland following Borders Buses lead on cycle-friendly buses.”
West Coast Motors managing director Colin Craig said: “The areas we cover include some of the most popular destinations in the UK for cyclists.
“Our trials on our X62 Galashiels-Peebles-Edinburgh route have proved conclusively pedal power and horsepower do work together.
“We very much see bus as part of the active travel solution and this initiative introduces a fantastic new dimension to sustainable greener travel.
“We recognise cyclists are prepared to ditch their cars for our bike-and-bus combination, all of which is great news in terms of reducing traffic congestion and vehicle emissions, enhancing the environment and encouraging people to jump on a bike and get active.”
Charlie Miller, regional sales manager at Scottish bus builder Alexander Dennis, said: “Colin and his team at Borders Buses have a reputation for setting the pace.
“This project is another example of the vision and foresight that has established them at the forefront of the passenger transport sector.
“Bikes and buses can make a significant contribution to a greener, cleaner environment and boost the tourism industry, particularly in rural communities.”