Former single speed to find blameless (9)

I believe the answer is:

exonerate

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'find blameless' is the definition.
I can't tell whether this defines the answer.

'former single speed' is the wordplay.
'former' becomes 'ex' (prefix meaning former or onetime).
'single' becomes 'one' (a single thing - only one).
'speed' becomes 'rate' (the speed at which something happens).
'ex'+'one'+'rate'='EXONERATE'

'to' is the link.

Can you help me to learn more?

(Other definitions for exonerate that I've seen before include "Officially absolve from blame" , "Clear of blame" , "Declare to be blameless (9)" , "Free of duty" , "Acquit" .)

I've seen this clue in the Sydney Morning Herald.

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