Typical boys’ toys — racing’s ending in terrible tragedy (8)
I believe the answer is:
gadgetry
'typical boys' toys' is the definition.
'racing's ending in terrible tragedy' is the wordplay.
'ending' suggests the final letters.
'in' means one lot of letters goes inside another.
'terrible' indicates an anagram.
The last letter of 'racing' is 'g'.
'tragedy' anagrammed gives 'gadetry'.
'g' inserted within 'gadetry' is 'GADGETRY'.
(Other definitions for gadgetry that I've seen before include "Mechanical tools" , "Small ingenious devices in general" , "gismos" , "The making of small ingenious devices" .)