The record breaking challenge is to cycle around the world in fewer than 100 days.
The 51-year old had been forced to abandon his first attempt through a combination of illness and injury.
He has just set off from a new starting point in Latvia and will cycle for 200 miles a day during the adventure.
Mr Smith said when he realised the record was 125 days he thought about "actually trying to make a piece of history, which is under 100 days."
Dumfries man Peter Smith is making a fresh start in his bid to become the quickest and oldest man to cycle round the world.