Replace to possessive noun of Racing bikes belonging to Fred Smith
https://www.englishclub.com/grammar/nouns-possessive.htm
Use the explanations here, and then let us know what you decide.
Did you figure it out yet? You'll need to add the verb to complete the sentence, but here's the complete subject:
Fred Smith's racing bikes ...
AMOGUS
Grade 3 Generosity
To replace the noun "Racing bikes" with a possessive noun belonging to Fred Smith, you would use the apostrophe and the letter "s" ('s) to indicate possession.
The possessive form of the noun "Racing bikes" belonging to Fred Smith would be "Fred Smith's Racing bikes."