Mr Pritchard, 62, served on a Polaris submarine with Tony – who was then a chief petty officer – in the 1980 s.
In later years they aimed up living in the same village and joined the same rugby club.
The retired offshore worker, also from Tillicoultry, told the BBC Scotland news website: “I’ve known Tony for over 30 years.
“We were in the Navy together – we then lived in the same area and ended up in the same rugby club.
“He was a pretty solid guy – he was a good guy who would do you a prefer any time he could. If he could help you he would.
“He was just a good, decent man.”
He added: “He loved his rugby – he played, he refereed, he coached, he was heavily involved in rugby in the village.
“It doesn’t surprise me that he was doing this ride for charity, that was Tony.
“It’s incredibly sad and disappointing that nobody has either seen anything, or if they have they have never come forward to say they’ve seen anything.”
The grandfather had been treated for cancer in the past and was undertaking the 104 -mile( 167 km) ride for a charity.
Extensive searches of the region – close to the West Highland Way – were made by coastguard and mountain rescue squads in the weeks after his disappearance.
Police said there had been nothing to suggest anything suspicious had happened to him.
Ch Insp Drew Sinclair said: “We have not uncovered any evidence at all of any criminality through the extensive searches and investigations we have conducted.
“It still remains a missing persons inquiry at the moment.
“We have traced his motions from Fort William, through to Glen Coe, through to the Bridge of Orchy Hotel, and then an unconfirmed sighting about a half mile south of the hotel from another lorry driver.
“From there, there’s been absolutely no confirmed sightings of Tony or the bike, which a year on, is unusual.”
Police are appealing for visitors to the area over the summer, and those currently in the area, to come forward with any information that might help.
Mr Parsons left an address in Ross Court, Tillicoultry, at about 09:30 on 29 September and caught a develop to Fort William, leaving the town on his bike at about 16:10.
He passed through Glencoe village at about 18:00.
Police have released video footage taken from Claymore Filling Station of him cycling through the village.
The cyclist is 5ft 9in tall, of stocky build, with short hair, a moustache and glasses.
He has a tattoo of an anchor on his upper right arm and a tattoo of an eagle on his left.
He was last seen wearing a distinctive red waterproof jacket.
Earlier, he was seen wearing a blue, long-sleeved cycling top, a high-viz vest, fingerless gloves, beige combat trousers, a silver and gray cycling helmet and walking boots.
He was carrying a silver and blue knapsack and had a yellow-framed bike with black handlebars.
Ch Insp Sinclair said the family had suffered since Mr Parson disappeared. He is married with two grown-up children and two grandchildren.
The officer said: “It has been an agonising year for their own families, who have had to get through Christmas, New Year, birthdays and anniversaries without answers about where their spouse, dad and grandpa is.
“Our believes be staying with them at this difficult time, and I wish to thank the local communities for their co-operation and support throughout our inquiries.”
He added: “Tony was last seen wearing cycling gear and the yellow-framed bike he was riding has not yet been found.
“I would appeal to anyone who may have ensure a piece of clothing similar to that which Tony was wearing, or who could have found the motorcycle, to please get in touch immediately.”