Four siblings are preparing for a 130-mile wheelchair push - 34 years after their grandad completed the same feat.
David Percival, 72, made the trip via roads and the North Sea from Sawston in Cambridgeshire to Amsterdam with three fellow wheelchair users in 1986.
Now his grandchildren will repeat the challenge - called The Percival Push - as a tribute to his endeavours.
His grandson Paul, 28, told the BBC: "This foolishness is in our blood. It's a Percival trait."
Mr Percival has used a wheelchair for more than 50 years after a motorcycle crash at the age of 17.
Since then, his family said, he has carried out "ridiculous challenges" to open up wheelchair access routes, including "insane" treks across Scottish mountains and the North Yorkshire moors.
However, David's journey to Amsterdam in 1986 was "possibly his hardest one", Paul said.
"We are going to set out to recreate that challenge as faithfully as possible, on the closest route that we can manage over the course of five days," he added.
The siblings - who are not wheelchair users - will raise money for the Arthur Rank Hospice and Action for Pulmonary Fibrosis.
The charities are close to their grandad's heart.
'Impressive and inspiring'
They said the training made them realise the everyday challenges wheelchair users faced.
"It's surprisingly hard to get around in a wheelchair, there are a lot of obstacles that you don't expect," Paul said.
"Suddenly you get a new affinity for the pavement and how 'unflat' it is. He has never once asked us to slow down for him.
"We never realised the effort it takes to keep up - that's been really impressive and inspiring."
Planning the journey by road, Paul added: "I wish he'd taken a straighter route - it wiggles here, there and everywhere down the country to Harwich."
Mr Percival added: "I'm very proud of all of it.
"I'm used to it - our arms are built to push that way but it's been a learning curve for them. I cannot believe the effort they are putting into it and their commitment."