bicycler vs biker

bicycler and biker both are nouns.

Word	Noun	Adjective	Verb	Adverb
bicycler	Yes	No	No	No
biker	Yes	No	No	No

As nouns, bicycler and biker are synonyms defined as:

Other synonyms of bicycler include bicyclist, cyclist, wheeler.

bicycler (noun)	biker (noun)
a person who rides a bicycle	a person who rides a bicycle