There is no definitive answer to this question as it depends on a number of factors, including the width of your tires and the width of your rims. That said, 2.35 is generally considered too wide for cross-country riding. This is because wider tires are more difficult to control on narrow trails and can lead to increased fatigue. Additionally, wider tires are more likely to pick up debris from the trail, which can clog up your drivetrain and cause premature wear.