A cyclist is set to compete in a 100 mile race to raise money for an Alzheimer’s charity after watching his grandmother lose her battle against the disease, before his grandfather started showing early signs of the illness.

Luke Garnsworthy, of Bow, is one of around 20,000 riders taking to in the gruelling Prudential Surrey-London challenge on the first weekend in August.

The Wick Lane resident saw his “larger than life” 83-year-old grandmother, Dorothy, succumb to Alzheimer’s in 2011. Now, his 84-year-old grandfather Bruce is showing early signs of the disease, which causes memory loss and dementia as brain cells die.

And 28-year-old Luke has raised £1,400 for charity the Alzheimer’s Society ahead of the ride, which is the second of three he is completing fr the cause this year.

“When my gran did first start suffering from it, I ducked under the covers and hid from it because she meant a hell of a lot to me,” he admitted.

“I didn’t handle it very well – I limited my visits to maybe once a year.

“I’m better now as my granddad goes through it, and completing this ride is my way of making it up to my gran and showing the support that I didn’t give when I was a lot younger.”

The race, which starts at the Queen Elizabeth Olympic Park, closely follows the route completed by the stars of London 2012. And Luke may find himself pedalling alongside German tennis legend Boris Becker, who is also completing the race.

To sponsor Luke, visit: http://uk.virginmoneygiving.com/LukeGarnsworthy.

For more information on the ride, which takes place over the weekend of August 3 and 4, visit: www.prudentialridelondon.co.uk.