Lunn -- a BMX racer and free rider -- was trail riding in Cabo with his friends when he got into an accident and suffered a fatal head injury.

"Jordie lost his life doing exactly what he loved," Lunn's family said in a statement to Pinkbike.

Lunn was also well known for his crazy biking videos ... with some clips getting millions of views on YouTube.

"Jordie had an incredible 20+ year career as a mountain biker," his family continued. "He will always be cherished for his heart and love that he gave to his family, friends, and fans, as well as the incredible talent that he had on his bikes."

Lunn's friend, Greg Watts, was with him during the trip ... and released a statement on Friday, saying "GUTTED. We lost a human that you hope everyone could be like."

"If he doesn’t make it to heaven then heaven doesn’t f*cking exist. I had the pleasure of spending his last few hours alive with him along with [Berrecloth, Brayden Barrett Hay and Lone Wolf Productions] and he was truly enjoying what he loved."

"Perfect day of riding in a perfect location. Just didn’t seem real and I still can’t grasp it. My condolences go out to his family because I know he loved his brothers and I know he was their glue."

Darren Berrecloth was with Jordie when the accident happened ... and tells TMZ Sports "We were riding a mellow trail in Mexico and he came up short on a gap jump and hit his head."

Berrecloth added ... "Jordie to me was a part of my family as I was a part of his. He was a brother to me as we grew up in a small town with nothing other than our parents love and our determination to ride bikes, have fun and get rad.

"Jordie was one of a f*cking kind, sibling of two brothers that if you had the pleasure of knowing the trio of bandits at the household you were always on your toes as you never knew what kind of Shenanigans were about to go down."

Berrecloth sent us a photo he took of Jordie right before the accident.

"I’ve loved Jordie as a brother from the moment we became riding buddies as biking will build that bond in friends. He was always a inspiration to me to be honest, his ability to see the positive in everything when I was down was uplifting."

"He had the heart of a lion and the hug of a grizzly bear," Berrecloth says.

"This loss to his family, his fans and everyone that had the beautiful opportunity to meet this amazing individual we call our brother, will be felt for years to come as 'legends never die' and Jordie f*cking Lunn in my heart will never ever be forgotten!!"