Damaged cables also cause lots of problems. Both inner and outer cable damage will result in all sorts of issues when it comes to smooth shifting. Replacing a cable will make a huge difference to how your bike shifts. Look out for old, split outer cable end caps, damaged outer housing, and also rust. Inner cables can also cause issues. Make sure you don’t have any kinks. Older inner cables may also fray and start to snap. Keep an eye out for this.