let something ride idiom informal
听之任之；放任自流
to not take any action to stop something wrong or unpleasant, thinking that action may not be necessary or is not yet necessary
Don't panic about the low sales - let it ride for a while and see if business picks up. 销售额低迷也不必惊慌——先观望一阵子，看看生意能不能有起色。