John Stewart, 54, of Carstairs, South Lanarkshire, was acquitted by a jury on Thursday of causing the death of Andrew McNicoll by driving without due care and attention on Edinburgh's Lanark Road in January 2012.
Mr McNicoll's parents, Ian and Lynne, were disappointed by the verdict but promised to continue campaigning for safer cycling conditions."
Mrs McNicoll said: "The only way forward for us is to work with Cycle Law and go for stricter liability.
"That's the most the important thing - to protect vulnerable road users."
It was alleged that Mr Steward overtook Mr McNicoll at an unsafe part of the road and that a trailer attached to his vehicle came into contact with the cyclist.
The prosecution lawyers claimed this led to him losing control of his bike and collide with a parked car.
The court heart that accident investigators were unable to prove the accident had been caused by bad driving.
In his closing speech, defence advocate Steve Love said Mr McNicoll's death was "sad" but the evidence presented implied it to be a "tragic accident" rather than a criminal act.
Mr McNicoll's family, who have set up charities to make cycling safer in Scotland, remained in court throughout the four-day trial.
Mrs McNicoll said: "The way forward is to campaign about something we think is better, that's what we're going to have to do."