Weir, a former Scotland rugby international, raised millions of pounds for research into the condition after his own diagnosis with the condition.
Now father of three James Clarke wants to carry on his work.
Mr Clarke, 42, from Hampshire, has already raised more than £440,000 for the My Name’5 Doddie Foundation set up by Weir.
Speaking about the rugby star, who died last month, Mr Clarke said: “The strength and determination he displayed whilst fighting MND was truly inspirational and the legacy he leaves is the stuff of legend.
“I didn’t play much rugby at school, but I promise to pick the ball up and drive towards the MND try line, supported by friends and family as teammates and score some points against this toughest of opponents.”
A black tie ball Mr Clarke organised in October raised more than £200,000 for the cause, and a second event in February has already sold out.
Mr Clarke said the first ball, held at Frensham Hall in Farnham, went “better than I ever could have imagined”.
He added: “I was completely overwhelmed by the support my family and I received on the night, and I am delighted we managed to raise as much as we did to fund the fight against MND.”
After being diagnosed with MND In December 2021, Mr Clarke began fundraising in July, completing a 50-mile cycle along historic Shipwright’s Way with his 13-year-old-son Ollie and 24 riders.
“Completing the cycle was the hardest thing I’ve ever had to do,” he said.
Mr Clarke, who lives in Wyck with his wife Lottie and children Martha, 14, Ollie and Matilda, six, added: “It was my arms that bore the brunt of the pain due to the stress of holding my body upright on the bike.
“There were a few big hills on the trail which proved to be a real challenge – at one point, my friends Gary Hall and Phil Hobley had to physically hold me up on either side just to make it to the top. I didn’t stop once, though. I was determined to finish.
“My body was in immense pain towards the last few miles, so having my son there alongside me was a real boost. I was very emotional crossing the finish line. I have never felt anything like it.
"If that helps just one family going through something similar to mine, then I know it’s a job well done.”
Jill Douglas, chief executive of the My Name’5 Doddie Foundation, hailed the “amazing effort by James and his family and friends”.
She added: “He is such an inspiring character and we very much appreciate his support.
“Like Doddie, James is giving so much of his precious time to raise funds to hopefully put an end to this disease. It is because of people like James that we can continue to fund our vital research and clinical trials so we can finally find a cure for MND.”