bike vs trail bike

bike and trail bike both are nouns.

Word	Noun	Adjective	Verb	Adverb
bike	Yes	No	Yes	No
trail bike	Yes	No	No	No

As nouns, trail bike is a hyponym of bike; that is, trail bike is a word with a more specific, narrower meaning than bike:

bike: a motor vehicle with two wheels and a strong frame
trail bike: a lightweight motorcycle equipped with rugged tires and suspension; an off-road motorcycle designed for riding cross country or over unpaved ground

Other hyponyms of bike include minibike, motorbike, dirt bike, scrambler.

bike (noun)	trail bike (noun)
a wheeled vehicle that has two wheels and is moved by foot pedals	a lightweight motorcycle equipped with rugged tires and suspension; an off-road motorcycle designed for riding cross country or over unpaved ground
a motor vehicle with two wheels and a strong frame

bike (verb)	trail bike (verb)
ride a bicycle