Harley Davidson Motorcycles

Steps to Reduce Vibrations on a Harley Davidson Motorcycle

Steps to Reduce Vibrations on a Harley Davidson Motorcycle

Harley Davidson motorcycles are best known for their classic styling and powerful V-Twin engines. While these signature engines are capable of impressive horsepower and torque production, long haul capabilities, and distinct rumble, they are also known for making vibrations. Surprisingly, Harley vibrations are not always considered a downside of motorcycles by riders; and many prefer these vibrations as they give Harley their distinct character and feel. In this article, find out why Harley Davidson motorcycles vibrate more than any Japanese motorcycle and what you can do to reduce these vibrations.

1. Do All Harley Motorcycles Vibrate Excessively?

Almost all Harley riders experience vibration at idle and higher speeds. However, the intensity of vibration on a Harley-Davidson motorcycle varies considerably depending on the model and engine layout. Some Harley models feature counterbalanced “B” engines that are bolted directly to the frame. Since these engines lack rubber-shock absorption, they produce minimal vibration at idle. However, at higher revs, the vibration may become prominent.

On the other hand, Harley motorcycles with rubber-mounted engines may produce harsh vibration at idle, but as soon as the rider accelerates, the vibrations reduce significantly.

This phenomenon has been observed in different Dyna, Sportster, and Softail models. Dyna and Sportster models are rubber-mounted, damping the vibration transfer to the chassis and rider. However at idle, these bikes tend to shake a lot. Softail models do not have rubber-mounted engines; their counter-balanced motors help decrease the vibrations dramatically at idle. However, the engine transfers more vibration to the frame and rider at higher speeds and on bumpy roads. Moreover, the older Harley models vibrate more because they feature a 45-degree V-Twin with a single connecting pin, resulting in an asymmetrical firing pattern that also causes vibrations. Harley has used this engine architecture for a long time to conserve the signature Harley sound and feel.

If you are someone who prefers a smoother ride, here are some tips to help you reduce vibrations on your Harley Davidson motorcycle.

2. Harley Davidson V-Twin vs Other V-Twin Engines

Harley Davidson is not the only motorcycle brand that manufactures V-Twin engines. However, the American brand has a unique take on common engine technology to ensure that all Harley bikes offer somewhat similar feel, sound, and look.

2.1 Engine Configuration

A V-Twin engine is a two-cylinder piston motor whose cylinders are arranged in a V-shape and share a common crankshaft. Harley places the two cylinders 45 degrees apart to create the signature sound and “vibration.” To reduce vibration in some bikes, Harley adds counterbalancers. Other motorcycle brands use 60-degree or 90-degree V-Twin configuration. The 90-degree V-Twins have the ideal configuration as they offer accurate primary balance and produce the least vibrations without the need for counterbalancers.

2.2 Compact Engines (Smaller Angle of Difference)

Since the angle of difference between the cylinders is much smaller, specifically 45 degrees, for Harley V-Twins than engines of other motorcycle brands, it allows for a more compact engine. However, the small angle of difference also contributes to harsh vibrations. This vibration is experienced more when idling on traffic signals. The engine may produce less vibration at higher speeds or rpms; however, the same may not be true for all models.

2.3 Counterbalancers

Harley’s older models lacked counterbalancers. Therefore, if you ride an older model, you will experience more vibration compared to newer Harley bikes. Though the newer Harley models feature rubber-mounted motors and counterbalancers, Harely adopted this technology much later compared to other brands because it wanted to continue its V-Twin heritage and brand identity.

2.4 Firing Order

As mentioned, Harley engines have an asymmetrical firing pattern because of their 180° firing order. As a result, each of the two cylinders fires at uneven intervals to create the distinct, loud, Harley rumble. Other brands manufacture V-Twin engines with a 360° firing order, so the two cylinders have even or symmetric firing patterns/intervals. Hence, the raw engine feel of a Harley is missing in other motorcycles.

3. Do the Latest Harley Models Vibrate Excessively?

With the introduction of the Milwaukee-Eight engine in 2016, Harley Davidson has successfully managed to reduce the vibrations. The Milwaukee-Eight engine is the ninth generation “Big Twin” engine and has four valves per cylinder, a total of eight valves. The motor also features a single-camshaft layout and comes with internal counterbalancers, which help reduce the vibration significantly.

Earlier models featured a Twin Cam engine. Except for Harley Softail models, all other Harleys powered by a Twin Cam engine lacked counterbalancers and produced harsh vibration at idle.

In 2016, Harley announced that the 2017 touring models and trikes will feature a counter-balanced Milwaukee-Eight engine. In 2018, the same Harley Softail motorcycles were also equipped with a Milwaukee-Eight engine. Therefore, 2018 onward models produce about 75% less vibration thanks to the new engine technology than the previous Dyna, Sportster, and Softail models.

4. Tips to Reduce Vibrations on Your Harley Motorcycle

Harley owners can reduce the vibrations on their motorcycles through accessories and mechanical upgrades. Here are some tips to help you achieve a smoother ride on a Harley.

4.1 Hand-Grips

Motorcycle anti-vibration hand grips are the most affordable accessories that you can use to maximize the riding comfort of your Harley. These grips are crafted from spongy material that can absorb excess vibration. Moreover, these grips may feature internal layers to optimize damping. Hand grips greatly reduce the contact between the rider’s hands and handlebars. As a result, the vibrations are not directly transferred to the rider, which helps reduce the shaky feel. When buying a motorcycle anti-vibration hand grip, make sure the grips are thicker in the palm area and have a comfortable ergonomic design so you don’t feel uncomfortable gripping them on long hauls.

4.2 Handlebar Dampers

Motorcycle handlebar dampers are another affordable accessory that you can mount on your Harley to reduce vibration. The handlebar dampers come with rubber mounts or bushings. Since these dampers are installed between the handlebars and their mounting points of the frame, they reduce the transfer of vibration from the handlebar to the rider’s hands. The rubber bushings absorb most of the harsh vibration, ensuring a smoother ride. Some handlebar dampers feature built-in counterweights that cancel out the vibration from the engine and counter the impact from the road, significantly reducing the overall vibration.

4.3 Fork Braces

Unlike motorcycle vibration hand grips and handlebar dampers, fork braces are not an anti-vibration accessory. Fork braces are essentially designed to improve the front fork assembly and front-end stability of a motorcycle; however, they also help reduce vibration by enhancing the front fork rigidity. You can mount fork braces for better control and handling and also benefit in the form of reduced vibrations on your Harley.

4.4 Seat Upgrades

Custom motorcycle seats, designed specifically for better comfort and reduced vibration, are readily available on the market. The gel inserts and additional padding act as shock absorbers and help in vibration damping. These seats dissipate vibration or absorb impact to reduce the direct transfer of vibration to the rider, ensuring a smooth and comfortable ride.

4.5 Engine Balancing

Engine balancing is a process through which vibrations produced by an engine can be reduced. For primary engine balancing, it is important that the components of a multi-cylinder engine, including piston and crankshaft, produce forces that are equal and opposite so they cancel out each other and generate less vibration. Counterbalancing shafts and harmonic balancers can also be added to the engine to counter the excessive vibration and ensure a smoother ride. It is worth mentioning that engine balancing is a complex process and must be performed by a certified Harley technician or mechanics that specialize in Harley Davidson engine balancing. If your bike’s warranty is valid, make sure you consult the owner manual and authorized dealership to inquire about the validity of warranty after engine balancing.

4.6 Engine Mount Upgrades

Engine mount upgrades are another effective method to reduce the vibrations on your Harley motorcycle because the way the engine is secured to the bike’s frame can affect the production and transfer of vibration produced during engine operation. Upgraded engine mounts are often made from polyurethane or rubber. Both materials help create a damping effect by absorbing and dispersing excess vibration. Moreover, rigid mount increases the stiffness of motor mounting points, reducing flexing and vibrations. Additionally, upgraded engine mounts are designed to reduce the contact points between the frame and engine. This in turn reduces the transfer of vibration from the engine to the rider, ensuring a smoother ride.

4.7 Harley Anti Vibration Module

Some riders enjoy the excess vibration as for them it is a distinct characteristic of a Harley motorcycle. The only reason they want to reduce the vibrations on their Harley is to safely mount their cell phones on the motorcycle phone mount. Such riders can simply use an anti-vibration module by Harley Davidson that is designed to reduce vibration damage to cell phones and other mounted devices. These modules have a special elastomer inlay that dampens the vibrations up to 60%, so you can easily use navigation apps on your phone while riding.

5. Maintenance-Related Tips to Reduce Vibrations on Your Harley

Harley Davidson motorcycles are known for their loud sound and vibrations; however, excessive vibration may be a result of poor maintenance or a mechanical issue. If you feel your Harley motorcycle is producing unusually harsh vibrations, make sure you perform the following maintenance tasks to identify and fix the underlying cause of vibrations.

5.1 Check Tires

Motorcycle tires with uneven wear or tread can cause excess vibration, making riding challenging. Improperly balanced or inflated tires can contribute to vibration on your Harley motorcycle. Therefore, it is recommended that you inspect the tire pressure and tire tread before every ride. Also, check the tire/wheel alignment if you experience more vibrations than usual.

5.2 Replace Motor Mounts

Worn-out engine mounts can cause misalignment and increase vibration production. If your motorcycle is making more vibration, make sure you get the motor mounts checked. Once identified, replace the damaged motor mounts immediately to avoid any large-scale mechanical failure as the increased vibration can also damage other engine components. Replacing damaged motor mounts not only reduces vibration but also increases engine life.

5.3 Repair/Replace Sprockets and Chain

Damaged motorcycle chains and sprockets can cause misalignment and uneven wear, leading to increased vibrations. Moreover, if the chain tension is not within the specified range, which is usually mentioned in the owner’s manual, it can cause jerky movements and excessive vibration. Tight chains put more stress on the engine, while loose chains increase engine tension. The vibrations created by damaged chains are transferred to the handlebars through footrests. Therefore, it is recommended that you check the chain and sprocket every 500 kms, lubricate, and adjust the chain as mentioned in the owner’s manual to avoid discomfort.

5.4 Use Better Fuel

Poor fuelling and poor quality fuel can also contribute to excessive vibration both affecting the air-to-fuel ratio and combustion efficiency. It is recommended that you refuel your motorcycle as needed and use high-quality fuel. This will not only reduce vibrations but also increase engine life and performance.

5.5 Adjust Suspension System

The suspension system is responsible for absorbing shocks and impacts from roads and dampen vibrations. Through preload adjustment, sag adjustment, and spring rate changes, you can significantly decrease vibrations on your Harley motorcycle.

Additionally, a properly adjusted suspension system can improve riding comfort and ride quality. On long routes, a well-adjusted suspension system can reduce fatigue by offering a plush ride. Therefore, even if you are not bothered by the vibrations on your Harley, adjusting the suspension system will improve your overall riding experience.

6. Last Words

Harley Davidson motorcycles vibrate at idle and higher rpms. However, the intensity of vibration varies depending on the Harley model and the engines they are equipped with. Since the latest Harley Davidson motorcycles feature a counterbalanced Milwaukee-Eight engine, they vibrate less than older Dyna & Sportster, and Softail models. Sometimes, harsh vibration is a result of poor maintenance. Therefore, follow the tips in this article to reduce the vibration on your Harley. If the issue persists, make sure to visit an authorized Harley dealership to get your bike inspected and serviced. Viking Bags offer a wide range of luggage bag options, including saddlebags, sissy bar bags, tank bags, tour packs, handlebar bags, and trunk bags.

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