The incident took place on Thursday evening as Chance Walters rode along Wyndley Lane just before 8pm. Chance, a member of Birmingham BMX Club, was confronted by three men, one of whom pulled out a knife.
They took his bike and drove away in a grey people carrier, with a logo badge missing.
Chance’s mother Drina Walters said: “These men parked up. the guy in the passenger side got out, grabbed Chance by his neck and pulled him off his bike.
“A second guy came out of the car and pulled a knife from his trousers and threatened to mark Chance if he didn’t hand over the bike.
“Chance let go, the one who had grabbed Chance took the bike, the third man, the driver, opened the boot, they put it in and sped off.”
“Chance is profoundly deaf, he enjoys his riding and racing – that’s what he loves.
"He wouldn’t expect something like this to happen."
"It left him traumatised but he managed to give the police a good description.
“These things, sadly, are far too common. You bring your children up the right way to do the right thing and someone goes and steals what they have worked for.
“We know it could have been so much worse but it makes you angry. I know the chances of getting his bike back are slim but you never know. He has a lot of people in the biking community looking out for it.
“But the main thing is that these people could do it again to somebody and they need to be caught to stop them causing distress to someone else.”
Chance described one of the men as white, 6ft, slim build with a black goatee beard, wearing a grey baseball cap and plain white t-shirt.
The second was mixed race, 6ft, wearing a green hoodie and the third was white, tall, skinny, with messy blonde hair with a grey hoodie and blue jeans.
A West Midlands Police spokeswoman said: “We’re investigating after a bike was stolen at knifepoint in Sutton Coldfield last Thursday (10 June).
“A 23-year-old man was riding his bike on Thursday evening when a car stopped next to him.
"Three men got out of the car – they assaulted the 23-year-old, threatened him with a knife, and loaded his bike into their car before making off.
“An investigation is under way. Anyone with information should get in touch via live chat at www.west-midlands.police.uk 8am – midnight, or call us on 101 anytime.
“Want to remain 100 per cent anonymous? Call Crimestoppers on 0800 555 111. Please quote crime number 20/992960/21.”