Can I ask for a cheap exercise bike for Christmas?
Have you ever just thought of buying one yourself?
No, I would just like to be given one for a gift instead.
Wanting an excersize bike without paying for it is your idea of a great Christmas. You can buy one for cheap and not have to worry about someone getting it for you as a gift. Some people might think it's rude to ask for, depending on who it is.
There's not going to be any Christmas without an exercise bike.
You can ask for what you want for Christmas, but expecting it to happen is kind of rude. What you're asking for may be hard to get, or too expensive. You should buy something yourself if you desperately want it, instead of relying on the good will of others.