Ask a Mechanic: Should Derailleur Cables Cross Under the Downtube?

When setting up the cable routing my new handle bars it seems that cables naturally want to go to the opposite side of the head tube; but this would require me to cross the shifter cables under the down tube. Is this OK? From: Jason

Crossing derailleur cables under a road bike’s down tube is fairly common. However, there are a few minor concerns with running the cables this way. Depending on the orientation of the cable stops on your frame, the cable may rub on the stop or slowly saw through your cable housing ferrule. Then there is the additional friction to consider at the bottom bracket where the cable will drag on the inside edge of the cable guide. Lastly, sometimes the cables will rub on each other where they cross. For all these reasons, it is usually best to avoid the crossed cable setup.

But, these are exceptions to every rule. Sometimes crossing the cables is the best way to ensure good shifting, especially if the bike has narrow handlebars, a short head tube, or if you prefer to have the handlebar tape finish close to the stem. It is also a good option if you don’t want your cable housing to rub on your head tube. If you are in doubt on whether the crossed cable setup is right for you, try both and then pick the one that works best with your handlebars and frame.

Welcome to our Ask a Mechanic column where our expert mechanics Daniel Slusser and Greg O’Keeffe answer your bike maintenance questions. If you have a question for us, please post it on the Art’s Cyclery Facebook Wall or e-mail Daniel directly at daniel.slusser@artscyclery.com. 

2014-04-25T11:54:07-08:00