Conversation so far:
Where was Tom Simpson born?
Tom Simpson was born in Haswell, County Durham, England.
Who were Tom Simpson's parents?
Tom Simpson's parents were Tom Simpson and Alice (née Cheetham).
Did Tom Simpson have any siblings?
Tom Simpson was the youngest of six children.
Where did Tom simpson go to school?
Are there any other interesting aspects about the Tom Simpson article?
Tom Simpson rode his first bike, his brother-in-law's, at age 12, sharing it with Harry and two cousins for time trials around Harworth.
When did Tom Simpson begin club racing?
Following his older brother Harry, Tom Simpson joined Harworth & District CC (Cycling Club) aged 13.
Did Tom Simpson have any wins early on?
Tom Simpson won the National Cyclists' Union South Yorkshire individual pursuit track event as a junior and the British League of Racing Cyclists (BLRC) junior hill climb championship.
Did Tom Simpson win any awards?
Tom Simpson won a silver medal at the national championships in Fallowfield and silver medal for England in the individual pursuit at the British Empire and Commonwealth Games in Cardiff.

Question: When did he start racing professionally?
Self-contained rewrite: When did Tom Simpson start racing professionally?