That £3.25m investment by Borders Buses, part of the West Coast Motors Group, follows a trial earlier in the year of three new double-decker buses running between Peebles and Edinburgh.
All three were custom-built with four on-board bike racks, plus wireless phone charging and free wifi.
Those bike-friendly buses proved so popular that the company retrofitted another double-decker with bike racks and decided to similarly equip all new vehicles going forward.
Its new single-deck Enviro 200 MMC vehicles have been custom built by Falkirk firm Alexander Dennis, and all 10 are kitted out with two bike racks.
Another 10 are set to follow by the end of February.
The buses will run on three routes – the X95 from Carlisle to Edinburgh via Hawick and Galashiels, the X62 from Galashiels to Edinburgh via Peebles and the 253 from Berwick to Edinburgh via Dunbar and Haddington.
The 253 service has four of the new vehicles in operation, making it Scotland’s first fully bike-friendly bus route.
The X95 has 10 on the go, and the X62 has four double-deckers carrying passengers already and will add six new buses in February, making it the region’s second fully bike-friendly route.
Colin Craig, managing director of Argyll and Bute-based West Coast Motors, said: “The areas we cover include some of the most popular destinations in the UK for cyclists, and our trials on our X62 Galashiels-Peebles-Edinburgh route have proved conclusively that 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 that cyclists are prepared to ditch their cars for our bike-and-bus combination, 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.”
The company’s commitment to getting cyclists on board has been applauded by Scottish Government transport secretary Michael Matheson.
The Falkirk West MSP was there to see the new buses unveiled and he said: “This is a welcome investment from Borders Buses, 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.”
All 20 new and forthcoming single-deck buses, able to seat up to 38 passengers, are powered by Cummins six-cylinder, Euro6 low-emission engines with stop-start capability and Voith automatic transmissions.
Charlie Miller, regional sales manager for Alexander Dennis, added: “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.
“Others will recognise that working in tandem, to use an appropriate expression, bikes and buses can make a significant contribution to a greener, cleaner environment and boost the tourism industry, particularly in rural communities.”