Learn Dutch: De spaak van het wiel is krom. - The spoke of the wheel is bent.

To emphasize that the spoke is bent (for instance, as opposed to broken), you can move krom to the front of the sentence. Because of the V2 rule, the verb is must stay in the second position, pushing the subject after it: Krom is de spaak van het wiel wel, maar niet gebroken.

Could I use gebogen instead of krom for bent?

You could, but krom is the better choice here. Krom is typically used for things that are crooked, deformed, or bent out of shape by accident. Gebogen comes from buigen (to bend) and usually implies a deliberate, intentional, or natural curve.

Could I express the possession differently, such as saying het wiels spaak?

No, that sounds very unnatural. In Dutch, adding an -s to show possession is generally reserved for people and proper names (e.g., Jans fiets). For inanimate objects like het wiel, you almost always have to use the van construction.

Is the phrase spaak in het wiel used in any common Dutch expressions?

Yes! Just like in English, the idiom een spaak in het wiel steken means to thwart or sabotage someone's plans. Another handy word is the verb spaaklopen, which means to go wrong or to break down (literally: to run spoke).