Like some bars in gymnastics

UNEVEN

Think of the equipment used in women's artistic gymnastics where one bar sits higher than the other. The term describes their mismatched heights.

In gymnastics, the "uneven bars" are a well-known apparatus where the two horizontal bars are set at different heights. The clue plays on the word "bars" to hint at this event, and "like some" suggests we're looking for a word that describes them. "Uneven" fits perfectly because it directly refers to the bars' differing heights.