I personally wonder why he feels the need to keep it all 50/50. While he's talking long term commitment, does he have reason to believe that you may not be around long term? He doesn't have to buy you bike - couldn't you all just rent one sometimes so you can join along? Does he do things you can afford on an approximately 50% of the time basis, since he seems interested in the 50/50?
Have you tried just sitting him down, telling him you can see a future with him, and levelled about how you feel about these things? If he doesn't understand then, seems like you have to get as sound of a sense as you can re: why? Are you not being clear enough? Is he not as good of a person as you might hope? How would you respond to such questions if you were a year after being broken up?
My gut feel is that he is not being reasonable with you, but cannot know, and the above questions seem - to me, anyway - like a reasonable start at figuring that out.
Hope it helps. Please feel free to check out my post "bad relationship?". I'd value your thoughts on my situation.
