Brake/Derail. Lines

[BiknBen]

While we're on topic, any specific rules regarding shifter housing length from the top tube stops to the shifters?

Also, running hydraulic brakes and the front hose seems too long. Any tips regarding the proper length?

the cable or hose should be just long enough that it does not interfere with steering when you turn the bars 90 degrees in either direction. Any longer than that is just wasted. It is not a problem but it simply more weight and maybe increased chance of getting it hung up on branches. The rule is to have just enough but no more than required. Every bike will be different depending on the length of bars and location of the cable stops.