MORE than 4000 cyclists are preparing to pedal from Ballarat through the Grampians on the Great Victorian Bike Ride this weekend.

Joining the throng will be Foster great-grandfather John Lane who, at 85, lays claim to being the oldest cyclist on the 591km, nine-day ride.

The retired anaesthetist started cycling at 70 to help his arthritic knee and has since taken part in three Great Victorian Bike Rides.

"One of my daughters, a physio, said 'Dad, what you need is non-weight bearing exercise, get a bike'," John says.

"I hadn't ridden for many many years, since I was a boy.

"I rode 2km up the road and 2km back, I was exhausted. My legs were shaking. Now I can whizz into Foster, and I do most days."

John has clocked up more than 6500km on his bike.

"I found the knee got painful if I didn't ride," John says.

His heart and lungs have also improved from cycling.

"You may not see this as a benefit, but I now have no trouble blowing into a police breathaliser," he says.

John wears red and white footy socks, colours of the Fish Creek football club, when cycling.

They cover an elastic stocking he wears on one leg from a motorbike injury.

"It makes me easy to find."

John says the Great Victorian Bike Ride has taught him that most people are physically capable of a lot more than they believe in themselves.

"It is a great holiday, even if it is a bit strenuous. You get terribly hungry and eat like a horse."

In its 25th year, the ride will begin in Ballarat on Saturday, travelling through Victoria's Western District and the Grampians.

Riders will pass through towns including Cobden, Mortlake, Dunkeld, Halls Gap, Beaufort, before returning to Ballarat on the ninth day.

For details visit Great Rides.