I was reminded recently that France was one of the biggest reasons for the Colonies' success in the Revolution. They contributed many boots and boats, and almost completely emptied their treasury, which was a cause leading to their own revolution. But why were they so eager to help America in particular? Did it have to do more with their good relationship with the Colonies or their rivalry with Great Britain, or something else entirely?
The French American Alliance was an alliance of convenience for both. That's why it fell apart almost instantly after the war. France wanted to weaken Britain. its American colonies were the largest and most prosperous and losing them would most certainly not be good for Britain. the reason why was as you said the French British rivalry.