Chris Adam, 38, was injured while taking part in a track event at the venue near Dunfermline, Fife, on Friday.

Mr Adam was taken to Victoria Hospital in Kirkcaldy after the crash but died on Sunday.

The keen biker, originally from Strathblane but was living in Erskine, ran dealership CA Motorcycles.

His devastated brother, Blair, told Sky News that business was booming and his sibling's life was "settled".

He added: "It's just so hard but I want everyone to know how happy he was."

Mr Adam leaves behind his four-year-old son, Spencer.

His family said: "Nothing could ever prepare us for this tragic accident and the sad outcome of losing our Chris.

"We all knew how much Chris loved his motorbikes - so much so that he turned this into a career with the start of CA Motorcycles.

"His life was 100mph, fitting in his love of bikes and career around raising his only son, Spencer.

"This is such a difficult time for our family, both near and far, but one comfort we take is Chris was doing what he loved when it all came to an end."

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Police Scotland said officers were notified of the crash on a track at around 12.10pm.

Inspector James Henry said: "Our thoughts are with the family and friends of the man at this difficult time.

"A report will be sent to the Procurator Fiscal."

Knockhill Racing Circuit said no other rider was involved in the incident.

A spokesperson added: "A full investigation by relevant authorities was completed following this tragic accident.

"Our deepest condolences are extended to the rider's family and friends at this sad time."