Here at Cycle Systems we teach our students to fit both bike brake and gear cables in a simple four step process. Knowing which step you are at can really help, and of course there are pitfalls along each one that we shall enlighten you about over the coming weeks.
To replace a cable on your bicycle you must make sure that you:
Measure the correct cable housing length before fitting
Prepare the cable housing in the correct way
Fit the cable properly into the handlebar end - brake lever or gear shifter
Fit the cable properly into the brake or gear mech
Measuring the Cable Housing
This week we will focus on measuring. Of course, when you are fitting any cable to a bicycle you will always need to feed it through its protective cable housing. So really the best way to ensure your correct cable length is to start with cutting the housing well. In other words, if you measure the fit of your cable housing, then the actual cable length is already correctly determined.
You may be cutting cable housing for either gear or brake cables of course, but the process is really the same whichever. Here are some basic rules to follow to make your cabling housing fitting as good as it can be and to avoid problems on your bike.
STEP 1 - NOT TOO SHORT
It’s important to ensure that whether you route gear or brake cables, that the housing is never too short. At the bar end, short cable housing will impede the ability of the handlebars to actually turn properly and you will not be able to steer. At the gear mech end, if a short cable is travelling into a gear mechanism it is likely to pull unnecessary pressure on the mech and the intricacies of gear changing will be affected.
Cable routed nicely along drop handlebars. You can see that the housing is measured snugly from the shIfter along the bar. (It will later be taped into place.)
Cable housing routed down from the bars into its first cable stop. You can see here that the housing has to be cut and measure twice to fit into some cross-top levers too. But the approximate curve from lever to stop is demonstrated.
STEP 2 - NOT TOO LONG
You also want to make sure any cable housing isn’t too long or flabby. If the housing was too loose there would be an unnecessary kink outwards in the housing. Make sure that doesn’t happens as obviously it could get caught up on things.
Pictured here the gear cable housing fitted in a nice broad curve from the shifter on the handlebar into the cable stop.
Seen here from above, the perfect gear and brake cable housing. Not too much slack, and yet the handlebars can also turn fully:
From the handlebars the housing is either fitted into the front brake or mech, or along the frame to the back. Again, not too short or too long but snugly along the bike frame.
STEP 3 - MAKE CURVES AS SMOOTH AS YOU CAN
If a bend in the housing is necessary, make it as smooth as possible as shown here:
This time, a nice smooth curve going into the rear mech:
STEP 4 - TEST THE CABLE IN EXTREMES
Once you think you have the cable housing properly measured, it’s always good to test it in an extreme position to see if it actually is.
Here’s another example of good cable housing length shown on a flat bar bike. There is no taping here and more freedom of movement. The cable housing is this time travelling from the handlebar and into the cable stop on the frame that will enable it to travel along the frame to the back brake.
But still you can see that the handlebars are turned to their maximum and still the cable is not pulling in this position.
The next step in the process is to properly prepare the cable housing before you actually fit it for good. In our next blog we’re going to show you exactly how to do that. It’s a necessity before actually threading in the relevant cables. Stay tuned and sign in here to make sure you never miss another post! Or sign-up to our newsletter for tips and ideas direct to your inbox.