Senior jump jockey Wilson Renwick has been forced to retire because of nerve damage in his left arm.
Renwick suffered multiple injuries in a fall at Market Rasen in May 2015.
The 36-year-old Scot now hopes to “do a Pendleton in reverse” by taking up professional cycling.
Double Olympic cycling champion Victoria Pendleton switched to horse racing in 2015, and lined up in this year’s Foxhunters Chase at the Cheltenham Festival.
Renwick was a leading figure on jumping’s northern circuit, and the most successful of a string of National Hunt riders to have originated from Hawick in the Scottish Borders.
Soon after his fall, still suffering from concussion and wearing a neck brace, he married wife Sarah, and admits to recalling little of the day.
Eighteen months on, a specialist has decided he will not recover sufficiently to race again.
“As well as the concussion, I broke a vertebra in my neck, my collarbone, my jawbone and a couple of ribs, and they’ve all healed,” he said.
“But nerve damage in my left arm means some of the muscle has wasted away and I’ve lost power in it, which won’t come back, so that’s it.”
Renwick, the winner of nearly 400 races, is now attached to the Italy-based Parentini cycling team and has risen to ‘Elite’ level – one category below professional.
He told BBC Sport: “The experts say endurance athletes are at their best at my age, but probably need to have started developing from 20. I’m maybe too old, but it’d be great to give it a go – 90% of my body is fine, and there’s nothing wrong with my legs.
“I have no solid plans, but doing a Pendleton in reverse and becoming a professional cyclist is the dream. Victoria did brilliantly getting to Cheltenham, and going some way to trying to emulate what she did would be quite something.”