Essex and Herts Air Ambulance (EHAAT) had to cancel their two motorcycle runs this year due to the pandemic, which would have raised around £60,000.
The charity said that's the equivalent cost of 27 potentially life-saving missions.
While their runs to North Weald and Harwich are cancelled, they're now asking bikers to take part in their 'I Did It My Way' challenge.
That means riding their own route of at least 60 miles during August and September, while paying the usual £10 registration fee.
Kerry Russell, Head of Events and Merchandise for EHAAT, said: "EHAAT motorcycle runs have become hugely popular days in the local biking calendar, with thousands of bikers riding out to support the charity.
"When the COVID-19 pandemic forced us to cancel both events, we know it was a major disappointment for our valued supporters in the biking community."
North Weald Motorcycle Run 2019 (EHAAT).
Kerry continued: "The two events would have raised around £60,000, or the cost of 27 potentially-life saving missions, but we hope that with the support of our biker friends 'I Did It My Way' can help make up that shortfall by raising vital funds.
"We are really looking forward to bikers sharing photographs of their rides with us, and to welcoming everyone back in person to one of our motorcycle runs in 2021!"
To register, visit EHAAT's website.