What are 'blooming' tyres?

Published: 07 December 2010

Q. I’ve heard some track day veterans commenting on how their tyres have “bloomed”. What are they on about?
Jamie Spencer, email
A. “Bloom” is tyre-speak for when an ingredient in the rubber migrates to the surface. You see the same effect on chocolate when it’s been kept for a while with those white-deposits on your Dairy Millk.

Track day enthusiasts will often have 'blued' tyres - where the oil has bloomed and migrated to the surface. It’s not that detrimental, more an aesthetic effect that some people see in the same light as scuffed kneesliders as a sign of a good pace.