Roe joins the Pro-Continental team having spent the 2014 season riding for BudgetForklifts in the National Road Series (NRS), finishing second overall on the individual standings. The 25-year-old spent two years racing with BMC but was forced to take time out of the sport in 2013 due to hip and back pain.
"My goal this year was to have a consistent season and I was happy to finish second in the NRS," said Roe who joins team as a GC rider. "I wanted to be good in all of the races and I felt strong throughout. I'm definitely at a level now where I am ready to return to a higher level.
"Drapac has got a really good race program — I definitely see it as a step up."
Spokes has spent the last two years racing in Europe with the Omega Pharma-Quick Step feeder team, Etixx. This season he won the overall at the Course de la Paix U23 while the 22-year-old rouleur has also represented Australia at the last two World Championships.
"After four years in Europe full-time, I'm looking forward to a change of scenery," Spokes explained. "I still hope to spend some time in Lucca, Italy, training. It will also be nice to spend more time with family and friends back in Australia.
"From an outsider looking in, it seems that Drapac has a really good atmosphere as a team and that's something I really like — where your teammates can also be great friends."
Spokes has twice finished sixth at the U23 edition of Liège Bastogne Liège and has also taken general classification victories at the Vysocina Tour in 2013 and the Tour de l'Eure et Loire in 2012.
Drapac's general manager Jonathan Breekveldt explained the two signings with bolster the depth and quality of the team in 2015 and is looking forward helping both riders continue their development as cyclists.
"Tim and Sam bring a mix of youth and experience to Drapac Professional Cycling for 2015 and both will equally exciting to work with," Breekveldt said. "Tim achieved his performance goals for 2014 and we can provide the next logical step toward his ambitions of returning to the WorldTour. His strengths and experience make him a key GC rider for the team in our 2015 race schedule.
"Sam is an exciting young talent who has significant development potential and will thrive in both his new team and racing environment for at least the next two seasons," Breekveldt added.
The two riders join Peter Koning and Brenton Jones in signing for the team as it prepares for its second consecutive season at the second highest tier of professional racing.