Translation:Cross-country skiing is your hobby but ice hockey is not.
It's grammatically weird to end that way without also changing the first part
"A is your hobby but B is not" or "Your hobby is A but not B" are both natural. On the other hand, "A is your hobby but not B" is a bit off...
It should still be accepted but if you're looking for English advice, it is not a very well formed sentence.