Gary Holder and Steve Turner, both in their 60s, are taking on Prudential RideLondon this Sunday (August 4) with their grandson Seth Holder's uncle, Paul Homewood, to fund raise for CLIC Sargent. Since Seth's experience, both families, granddads and his uncle have raised more than £10,000 for CLIC Sargent, and are aiming to raise another £2,000 this Sunday at RideLondon. Granddad Gary said: "We are not regular cyclists, only two 60-year-old granddads and an uncle who want to do their bit. "We set up a Just Giving page to give something back. We know 100 miles is not going to be easy, but any donation will be gratefully received." Seth was just three-years-old last summer when his mum and dad, Leanne and Lee Holder, from Barnstaple, first noticed something wasn't right. What followed was open heart surgery, losing a kidney for Seth and a devastating cancer journey for the whole family when he was diagnosed with Wilms' tumour - a type of kidney cancer. Leanne said: "We first noticed something wasn't right about two weeks before Seth was diagnosed. "He was getting on and off temperatures and then he went pale and off of his food and so we took him to the GP. "She didn't take any risks and sent us straight to the children's ward to get tests as she could feel his liver was enlarged from pressure from his kidney. "The hospital did an ultrasound that afternoon and discovered a tumour. In that moment we were devastated and our whole world fell apart." The family were sent to Bristol for further tests and treatment and to Great Ormond Street Hospital in London for surgery. Leanne continued: "Seth had open heart surgery for eight hours and had to go on a heart bypass to remove the tumour in his kidney. It was so awful. "They said there was a chance he might not make it and it was horrible - waiting those eight hours - but we trusted them 100 per cent." The impact of Seth's cancer on the family was huge. "We had to travel two hours for Seth's treatment when he was at hospital in Bristol - and over an hour to get to Exeter too. It was a lot of travelling and the journeys used to take it out of him - but it's something you get used to," Leanne added. "The financial impact of petrol and food was huge. We had to pay for breakfasts, all lunches and teas in hospital - which all added up." During Seth's treatment, the Holder family were supported by CLIC Sargent. The charity provided free accommodation at Sam's House, a home from home for the family close to where Seth was treated in Bristol and social workers to support the family. Leanne said: "Our experience would have been completely different without CLIC Sargent. We would have had so many more stresses, worrying about money. CLIC Sargent help take those stresses off of you." Seth, who is now in remission and starting school in September, will be at the event to cheer on his granddads and uncle alongside the whole family and CLIC Sargent. To sponsor Team Seth's challenge, visit: https:\/\/www.justgiving.com\/fundraising\/sethssargents .