Former Miss Great Britain finalist Kay Kerslake, 62, died from secondary breast cancer in November 2016.
She went through treatment alongside her husband, dentist Alan Kerslake, during his fight against bowel cancer.
Alun, who is now in remission, raised £2,000 for charity Breast Cancer Now through donations from 400 mourners at her funeral last year.
He also donated £9,000 to Cancer Research UK after a charity trek up Mount Kilimanjaro in 2014.
And on Sunday, July 30, the 62-year-old continued his fund-raising mission at the Prudential RideLondon-Surrey.
He said: “I was thinking of Kay all the way through the ride, especially in those moments where you’re really battling to get up the hills. The cause is so close to my heart because of her.
“It was very, very emotional. At the end of the ride, I went along to the Breast Cancer Now information board and saw it was next to one from the Guide Dogs charity.
“That was so apt, because Kay loved her dogs. We had two golden retrievers, Kato and Nico, and I knew just where I stood in the pecking order – but that was fine!
“She was a beautiful woman, a wonderful wife and a fantastic person. Kay was always so positive throughout her illness.
“We went through treatment together, so knew what one another was going through, but she kept her suffering to herself.
“She’d never talk about the pain she was in and kept saying she was going to get better, even when we both really knew what the end result was going to be.
“Last year, she started redesigning the house, with new curtains, bed covers and decorations. She never said it at the time, but, looking back, I think she was making the house right for me to live on my own.”
The couple, who lived together in Churchill Close, Uttoxeter, met when Kay was Alan’s patient at Balance Street Dental Practice in the 1980s.
They subsequently enjoyed a whirlwind romance and a long marriage.
The inseparable pair also launched Staffordshire Clinic, in Dove Bank, where Kay was practice manager.
She was crowned Uttoxeter Carnival Queen in 1972 and was a Miss Great Britain finalist in 1976.
Alun said: “It was literally love at first sight. Kay Shaw, as she was then, blew me away.
“I met her in May, proposed two weeks later and married her in August. We were married 30 years.”
After finishing the 100-mile bike ride in in six hours and 42 minutes, including two stops, Alun spoke about the devastating effect of cancer.
He said: “Cancer in any form is so cruel. You go to some dark places and wouldn’t wish it on your worst enemy.
“We’ll all be affected by it in one way or another in our lives and I’m trying to do my bit to prevent it.
“I was discharged two years ago and I’ll still go back at the end of next year for some tests, but, at the moment, everything is ok. You never know, though.
“It scares me – there’s no two ways about it. Not a day goes by when I don’t think about it and worry. It’s totally indiscriminate.”
Sian Wilkinson, challenge events manager at Breast Cancer Now, said: "We are so grateful for Alun’s wonderful support.
"We hope he really enjoyed taking part in RideLondon-Surrey, while raising much-needed funds for breast cancer research.
“Breast cancer is a devastating disease that still cuts short the lives of around 11,500 women and 80 men each year. We want to change that.
“With every bike ride that’s done and marathon that’s run, we’re powering research that’s finding new ways to prevent, detect and treat breast cancer, until the day when we stop it once and for all.
"With supporters like Alun by our side we can make it happen faster."
Facts about breast cancer
Breast cancer is the most common type of cancer diagnosed in the UK and refers to any cancer that starts in the breast.
More than 50,000 women are diagnosed each year in Britain and nearly 1,000 of those die from the disease each month.
Despite common misconceptions, the condition is also sometimes found in men, with around 350 male patients in the UK being diagnosed each year.
The disease usually starts in the lobes – glands in the breast where milk is produced – but can spread to other parts of the body through blood vessels or the lymph system.
A Breast Cancer Now spokesman said: “If untreated, breast cancers can grow bigger, taking over more surrounding breast tissue.
“Breast cancer that has not spread beyond the breast or armpit is known as primary, or early, breast cancer.
“However, sometimes breast cancer cells break away from the original cancer and enter the blood or lymph vessels.
“Travelling though these vessels, cancer cells may settle in other areas of the breast or in the lymph nodes of the breast tissue, forming new tumours.
“They may also spread to other areas of the body where they can form new tumours, called secondary breast cancer.”
Symptoms to look out for include changes in the size of the breasts, new lumps of tissue, blood-stained discharge from the nipples, a rash on or around the nipples, a lump or swelling of the armpits and dimpling on the skin of the breasts.