That is a very vague brief
For inspiration google "cycling , happy , images" and go from there.
Think about how the poster will grab attention and quickly get the key messages that you want to get across.
Will you use shapes and vector art or photographs , or both.
If you want to use stock images you could type the same terms into the Adobe stock search bar. It will return many images.
Without a more specific explanation nobody can tell you much. You haven't even mentioned the nature of your business/ pointed to a web site. I mean I could come up with tons of designs on pretty much every subject in a nanosecond, but none of that may be relevant for your specific case - clearly race cycling is different from mountain biking which in itself covers a wide spectrum from slow exploratory excursions to competition rides down steep hills. Need I go on? You really have to provide a lot more information if you expect someone to save your behind and provide pointers or even an ingenious idea...
What I do is open MS Word, and type all the words related to activity I can think of. Then I hit those words with a Thesaurus, and generate more words. I then mix them up, and see what pops. The words then generate the graphics, and you see how they fit together. Just start typing, and the words you use will take you in all sorts of directions. You'll know better than us what you need to include and areas to stress.
Off the top of my head, text that becomes roads (I was going to say paths, but that might be confusing in a Photoshop forum) Wheels that have spokes can lead off in all directions to demonstrate the myriad options. Now I am seeing those spomes becomeing a maze with paths/routes crossing over other paths. Streamiled helmets motion blurred into text, or into the maze. I can see it all in my head right now.
Just don't go crazy with the art work, because sure as eggs are eggs, some **** of an art director will bounce off your ideas and try to change them. They have to do that to justify their existance.