I have a Schwinn bike from probably mid 2000's. The front tire has a regular valve cap that I can twist off and pump with a floor pump. The back tire has an oval cap that I cannot get off. And it seems like it is attached onto a tube, not just a regular valve like the front tire. I can't pull off the cap or twist it off. Not sure how to get it off to pump the tire.
I don't bike a ton and am not sure if I am using the right terminology. It might be too vague but if anyone knows what I am talking about I appreciate the advice!