Why Road Bikes Are So Loud?

The Short Answer is:

Road bikes can be loud due to various reasons such as the freewheel design, carbon rims amplifying road noise, and the number of contact points. The noise can also be a sign of a problem that needs maintenance, such as chain cleaning, bolt tightening, or replacing broken parts. Some high-end bike manufacturers even market their signature noise as a branding tool.

In recent years, cycling has become an increasingly popular mode of transportation and recreation. With the rise of the pandemic, the demand for bicycles has skyrocketed, and manufacturers are struggling to keep up with the demand.

While cycling offers numerous benefits, such as physical exercise, easier parking, and reduced consumption of fossil fuels, there is one aspect of cycling that has puzzled many: the noise level of road bikes. In this article, we will explore the question “Why Road Bikes Are So Loud” and the possible reasons behind this phenomenon.

Understanding the Noise Sources on Road Bikes

Road bikes are prone to making noises that can be frustrating and mysterious. The most common causes of these noises are dirty or dry bearings, which can be found in several places on the bike that use bearings to rotate smoothly, including the headset, front/rear wheel axles, pivots (MTB), derailleur bolt, and water bottle cage.

Noises can also occur where different parts join, such as weld seams or screw joints. Carbon fiber frames are especially prone to generating loud noises. To diagnose and remedy these noises, you can check that your gear or brake cables are not hitting against the frame or other parts of the bike, secure them to the frame using cable ties, and apply some grease to the point where the cables enter the frame.

Spokes can also cause noises if your wheels are not properly centered. If you hear a rattling noise from the handlebars, it might indicate that the road bike has loose handlebars that need tightening. Other bike components, like bottle holders or mudguards, might also need tightening. If you’re having trouble diagnosing the noise, it might be time for a little TLC.

The Role of Drivetrain Components in Road Bike Noise

The drivetrain components play a crucial role in the noise produced by a road bike. A constant clicking sound, especially in certain gears, could indicate that the shifter cables have stretched enough to pull the chain. On the other hand, a creaky squeaking sound could mean that the bike has a dry chain or bearings.

Cleaning and lubing the chain is usually a good place to start with any weird noise, but if it doesn’t solve the squeak, you may need to maintain or replace some bearings. Creaking and squeaking noises are annoying and can be a sign of more serious problems.

Damage to component parts may result if they are left unattended. Creaking is usually caused by two things rubbing together, such as a crankarm rubbing on a spindle. It could also be due to a misaligned rear derailleur, dirty chain, worn cassette, or other factors. Therefore, it is important to diagnose the source of the noise and take appropriate measures to fix it.

Tire Noise and Road Surface Interaction

Road bikes are loud due to the interaction between the tire and the road surface, which generates tire noise. This noise is caused by the vibration and air displacement that occurs when the tire and road surface come into contact.

The tread pattern and road texture both play a role in this interaction, with small tread gaps and larger aggregate sizes producing higher noise levels. This noise can be categorized into two types: structural borne noise and vibration (SBN) and airborne noise (ABN), with one type dominating the other depending on the frequency range of interest.

The use of low-noise road surfaces is one of the most effective interventions to reduce tire/road noise, as it acts directly on the source of the noise. The interaction between texture and tire/road noise has been studied experimentally, with close proximity (CPX) method used to measure the near-field tire/road noise.

Aerodynamic Factors and Wind Noise

Road bikes are loud due to aerodynamic factors and wind noise. Aerodynamic resistance is responsible for about 90% of the total resistance at speeds larger than 40 km/h on flat terrain. The faster a cyclist goes, the harder the wind blows, and at speeds over 9 mph, it becomes the dominant force of resistance.

The majority of modern bicycles and cyclist postures are optimized in terms of aerodynamic resistance. However, the optimization of aerodynamics can lead to increased wind noise, which is the sound produced by the air moving around the bike and the cyclist.

The wind noise can be reduced by changing the cyclist’s posture, using aerodynamic equipment, or by using a wind tunnel to test the aerodynamics of the bike and equipment. In conclusion, the loudness of road bikes is a result of the trade-off between aerodynamic optimization and wind noise reduction.

Factors Affecting the Perception of Road Bike Noise

Road bikes are known to produce noise while riding, and several factors can affect the perception of this noise. The five main factors that influence why road bikes make noise are loose handlebars, worn-out pedal bearings, gear-changing problems, a broken or worn-out bottom bracket, or brake pads rubbing against the wheels.

These noises are not severe and can be easily fixed. However, the perception of noise can also be affected by personal factors such as age, gender, and experience, as well as environmental factors such as air pollution and noise pollution.

Noise pollution from road traffic can cause annoyance, nervousness, anxiety, and mood change, as well as cardiovascular disorders, hypertension, or cognitive effects. Therefore, it is essential to maintain road bikes properly and consider personal and environmental factors that can affect the perception of noise while riding.

Techniques for Quieting Road Bike Noise

Road bike noise can be annoying and distracting while riding. Here are some techniques to quiet your bike:

1. Clean and lubricate your chain. This is usually a good place to start with any weird noise. If it doesn’t solve the squeak, you may need to maintain or replace some bearings.
2. Check your headset bearings. Dirty or dry bearings can cause squeaks and creaks. Use a pick to lift the bearing seals in the middle of the pulley on both sides. Wipe away any visible dirt. With the bearings exposed, spray a “speed” degreaser, or any degreaser that doesn’t require washing onto the bearings. Let it sit for 5 minutes and dry with a clean rag. Clean and re-grease your headset bearings.
3. Check your cables. The brake, dropper post, and gear cables are often overlooked when noise-hunting and trying to silence your bike. Make sure they are properly lubricated and adjusted.
4. Check your wheels. If there is any clicking issue related to the tires, you should pull off the wheel and make sure that it is straight (aligned correctly) when you put it back on. This will prevent rubbing on the tires.
5. Check your pivots and bearing locations. Rocking the bike while putting your fingers on the pivots and bearing locations, and spinning each bearing center can help target these sounds by process of elimination.

By following these techniques, you can diagnose and fix the common bike noises and enjoy a quieter ride.

Conclusion: Why Road Bikes Are So Loud

In conclusion, there are several reasons why road bikes can be loud. Some of the main factors include loose handlebars, worn-out pedal bearings, gear-changing problems, a broken or worn-out bottom bracket, or brake pads rubbing against the wheels.

Additionally, higher-end freewheels can also contribute to the noise. While some riders may enjoy the sound of their bike, others may find it annoying or disruptive. Regardless, it’s important to properly maintain your bike to prevent excessive noise and ensure a smooth, enjoyable ride.