"Rattle, clatter."
Do you ever hear sounds like this when riding your bike? That might be due to loose cables.
If you do a rough count, there are about 40 parts that make up a bicycle.
There's the frame and fork, which form the skeleton; the saddle and handlebars, which support your body; cables connecting the brake levers to the brake assemblies; and the chain, which engages with gear teeth to transfer power, among many others.
Today, I'm going to talk about cables, which are often cited as the cause of those annoying noises.
They are constantly under tension.
Before explaining why cables are often the source of these noises, let's learn a bit about the cables themselves!
The cables routed throughout the bike—sometimes called wires or housings—are components used to operate the brakes and shifting system, and they are kept under constant tension. Let's disassemble one to see how it's built.
Here is what they look like in detail. They are made of quite intricate parts. The inner cable running through the middle is twisted like a rope used for tug-of-war, and the outer casing also has a coiled structure.
Thanks to this, they are durable enough not to snap, even when we squeeze the brakes with all our might or shift gears repeatedly.
They do get loose…
Though they work hard for us, cables do occasionally get loose. We refer to this phenomenon as "stretch." It's a symptom we frequently encounter during our daily maintenance and repair work.
I tried a little experiment with the derailleur.
After adjusting the gears and securing the shift cable in the proper position, I marked it with masking tape…
Then, I pulled the cable with enough force that wouldn't break any parts.
When I operated the shifter again, it made a clattering noise and wouldn't shift properly. One of the causes of shifting noise is this cable slack.
So, I loosened the cable again and re-secured it with the correct tension. As shown in the photo, I was able to pull and secure it several millimeters further.
Even pulling it lightly by hand showed that the cable had stretched and loosened by that amount. In reality, this is not just the stretching of the wire itself; it also occurs because tiny gaps in the cable stops and outer casings get filled in, making it appear as if the cable has stretched.
If the cable gets even a few millimeters loose, the derailleur will shift out of alignment. If that happens, shifting won't work correctly, and in the worst case, the chain could come off, damaging the frame or breaking parts, so you'll want to fix it as soon as possible. The same applies to brakes, as they will become less effective.
Of course, we always perform this process to remove that "stretch" so that doesn't happen.
It still stretches more – Initial stretch
However, there are times when it continues to "stretch" further. This is especially common with new bikes, and we always explain it as "initial stretch" when delivering a new bike.
Symptoms include:
- Brakes feeling a bit loose
- Gears not changing when shifting or making strange clattering noises
Actually, this isn't just about cable stretch; it's a misalignment that occurs as new parts settle in, and it can be resolved by re-securing the cable and adjusting it.
If you leave it as is, you might not be able to control your bike well when you need to brake suddenly, or you could damage your chain or gear teeth, so please bring your bike into the shop early.
The discomfort or strange noises that a rider feels are significant signs from the bicycle.
If you've been riding with these lingering concerns, come in and let us sort it out for you!