Vibration is part of the motorcycle riding experience. But too much vibration, through the handlebars, seat or footpegs will slowly wear you out over a longer ride. To begin to fix excessive vibration you need to determine when it is happening, such as on hard acceleration or at a set rpm or constant speed. Also, take into account that your ride will vibrate due to its design – a single or twin-cylinder will have more natural vibration than a multi-cylinder rubber-mounted motorcycle. In this post, I look at fixing excessive vibration and reducing vibration that comes with the design.
For safety’s sake – when you notice excessive vibration, do a complete inspection of the motorcycle. Look for anything loose, missing or for broken parts. Checking every nut, bolt, and fastener. Use the correct wrench or socket, for critical items (wheels, frame, brakes) check for proper torque, as per your service manual. Check wheels for signs of missing balance weights, mud or debris sticking to the rims or physical damage to the rims or tires. Worn tires, especially uneven wear can be a cause. If the bike has sat in the same spot for up to 2 weeks or more the tires may have developed flat spots. Gentle riding will correct this problem naturally.
If you can’t find an obvious problem move on to a more detailed diagnosis.
If at any speed, vibration is accompanied by handling issues – immediately stop riding and start diagnosing. Continuing under these conditions is exceptionally unsafe since there is probably something very wrong and in need of attention.
Best Vibration Fixes
Handlebars & Grips
Poorly designed and constructed handlebar-grips combination can transmit a lot of vibration to your hands and arms. Eventually, this will fatigue your upper body. Fortunately, grips and bars can be upgraded pretty economically. I would first start with better, more padded, vibration-reducing handgrips.
Grip Puppy Comfort Grips – are a quick and easy way to reduce vibration immediately. Made of soft dense foam and designed to slip over existing grips, effective and easy to install. The downside is the foam will wear out, and faster with more use of course. There are some that complain about them ripping during installation, but if you follow instructions and don’t force them on there should be no problems. Easy to install and they work well, not much else to say.
For Harleys – these increase the grip’s diameter and add a padded vibration reducing foam layer. The style is 100% Harley Davidson too!
Weights change the physical dynamics of your bars and how vibrations travel through them. Similar to a musical tuning fork, the weights change your handlebars amplitude of vibration by physically changing the weight profile. If you are the curious type and want to be sure these will help – you could temporarily add weights to your bars (like tape a bunch of quarters to the ends), and see what amount of weight provides the most improvement. Most report weights reduce excessive vibrations felt in the hands.
Two-fer! – if you are thinking about adding cruise control – Korokin makes a bar end cruise unit, that also acts as a bar weight. They sell matching weight for the non-throttle side. Designed to be low profile with an integrated look. Friction is set by rotating the knob that sticks out from the handlebar end.
Your butt is continuously vibrated, some stock seats do well, others can be painful. A quick solution and comfort upgrade to an air padded or beaded seat cover. Many riders have used these to extend their daily riding range and make the trip a lot more enjoyable.
Tires & Wheels
Wheel assemblies are a prime source of newly developed vibration. Check the tires treads – do you see “cupping”, this is a series of unevenly worn patches. Cupping can indicate suspension problems also. It may indicate you have been running underinflated tires, but the wear causes the wheel to run out of balance. Get the wheels balanced, replace the tire(s) and keep inflated correctly. This DIY wheel balancing kit uses free moving ceramic beads to constantly adjust where needed to keep your wheels balanced at all times – genius design!
Bad wheel bearings can cause vibration, especially at certain speeds. To check, lift each wheel off the ground so it can turn freely. As you rotate keep a firm grip on the wheel, feel for any rough spots, or higher effort required to turn the wheel. In extreme cases, you may hear squeaking or noises from the bearings. There should also be no side-to-side movement (grip the tire on the outer most diameter to feel for this). Also, check that that each wheel will freely rotate after it is released. If the wheel slows down dramatically the wheel bearings should be inspected further, but dragging brakes are a more likely cause.
Chain & Belt Drives
Check rear wheel alignment, for either chain or belt final drives. Make sure there is no binding at any point (get the rear wheel off the ground, rotate by hand). Also, check for excessive chain wear. At the rear sprocket, around the “3-o’clock”, on a line that extends from the swingarm, pull it off the sprocket. If the chain pulls away from the rear sprocket more than 1/2 the height of a sprocket tooth then it is likely worn out. Belts should be inspected for missing teeth and any signs of fraying or chord separation.
Chains can wear and develop kinks that are hard to see, but you can feel the resistance rotating by hand. To check for serious kinks, remove the chain, and lay it out flat, full length on a table (link openings vertical, as it would sit on the motorcycle). You will notice kinks where it doesn’t sit flat. With the chain off you can measure the accumulated wear by first compressing all links together over a section. Measure this compressed length versus it pulled out to maximum length. Chain manufacturers have specifications for maximum chain stretch. Be precise, measure from the same point to another, for example – the center of one link-pin to another, over at least a foot on the chain.
You may notice a pulsing through either front or rear brake levers, this could indicate a warped rotor, sticking cylinder positions, or even worn caliper bolts. Check for loose or missing axle clamp nuts when you are down there. Also, if you have used a silicone based cleaner or detailer and any has landed on the rotors the brake pads may be sticking and grabbing when applied.
The bearings in the front steering head, where the front end rotates in the frame, do wear. This is usually on high mileage machines but can show up sometime after a serious front end “bump”, with say the curb. Raise the front end and move handlebars side to side, if there is an uneven feeling or sticking the bearings are worn.
Driveline & Frame
A worn or dirty chain, or belt drive and related sprockets. Check for wear, adjust and clean dirty components. On s shaft drive, check for wear or damage to u-joints, bushings, bearing or low differential oil.
If you have rubber mounted isolation system, check all bushings and fasteners. Verify the correct adjustment of positioning turnbuckles and guides. Check mounting points, especially where the engine mounts to the frame.
Be aware that a bent frame can be a fundamental cause of vibrations. This is unlikely to just occur over time, it usually is the result of a significant impact. Something to check on a used purchased bike for sure.
Knowing the cause of vibration is the first step toward finding solutions. Vibration, at the most basic level, is a physical result of the transfer of energy. The energy coming from the engine, or motion of your motorcycle.
Vibration comes from rotating or reciprocating parts that are, to some degree out of balance. It may also be caused by components and parts that are not secured properly or are worn out, or even coming apart. Poor maintenance can also contribute to your vibration problems. And it can be caused by all of the above working together at just the right time.
You need to acknowledge that some vibration is just part of any particular design. A single or 2-cylinder is usually more vibration prone than a multi-cylinder engine. At certain speeds, engine RPMs or conditions, and based on the overall design is creating and channeling vibrations. It may be very noticeable, but there is nothing particularly wrong, broken, or worn out.
Some Unexpected Sources
Some things can cause vibration that you wouldn’t expect – like dirty oil, clogged air filter, worn or out of adjustment ignition systems. Some basic engine maintenance items can cause poor performance that translates to weird vibrations. Vibration has even been reported fixed by cleaning and adjusting final drive chains!
Don’t overlook suspension. If you notice uneven tire wear this is an indication of suspension problems, but worn shocks and springs, low or very old fork oil can contribute to overall vibrations.
Do not overlook anything recently added/upgraded. Newly added accessories, like saddlebags, or windshields should be suspect. Even the loading of cargo on your motorbike is a potential source.
Designed In & Out
Some vibration can be inherent in the fundamental design of the motorcycle itself. A single or 2-cylinder engine is more likely to have vibrations than a 4 or 6-cylinder. Manufacturers often engineer a counter-balancing system that rotates opposite to the power producing assemblies.
In a multi-cylinder engine, the opposing cylinders are effectively counter-balancers.
Due to cost requirements and engineering misses, some bikes are just more prone to vibration. Certain designs isolate the engine-transmission and final drive with rubber mounting. This adds cost and complexity but can be very effective. More maintenance is a downside tradeoff, with more parts to adjust and wear in return for a smoother ride.
So, you can’t effectively do much to change the basic design, short of replacing the bike. However, you can work to adjust the vibrations’ frequency (making it less annoying) and also isolate the rider from remaining vibration.
Prolonged vibration can be harmful, excessive and prolonged encounters with it is not normal or natural to the human body. Anyone with some riding experience has felt numbness in the hands, feet or rear-end after a long ride. Prolonged exposure to direct vibration can fatigue the rider and even be dangerous. Numb hands and feet reduce reaction times. Riders have reported blurred and double vision, carpal tunnel syndrome, and even heart issues – likely associated with low amplitude vibrations over extended periods of time.
Reducing and eliminating vibration makes the ride more enjoyable and will reduce any health-related risks.
To fix the problem you need to isolate or narrow down the potential sources. Then inspect, adjust, fix or modify the conditions causing or potentially causing the vibrations. Approach the problem in a methodical way, with some experimentation may be needed. Often there is no direct connection, so you have to play detective.
At low speeds does pulling in the clutch, or reducing RPM change the vibration? If yes, then it could be engine related. If while doing the above and applying only front or rear brakes vibrations are noted this could point to braking issues on either end. If the vibration increases notably with RPM then suspect motor or mounting/frame issues, if it increases with speed it could be alignment or suspension related.
If the cause is not obvious you will need to dig deeper. First look for obvious worn, missing loose parts. Wheels and tires are prime suspects. Do a complete maintenance check-up routine.
Start the engine, let it warm up – is there excessive vibration, is it at all, or just certain RPM’s? If all maintenance is done, all fasteners are OK, you may have carburation, ignition or internal engine issues.
If you do not find a likely source, take a careful and deliberate test ride. Braking with front only, then rear only may lead to brakes or wheels issues on each end. Take note of how the vibration appears. Is it constant, or does it change, or get stronger with RPM, or speed?
The goal is to either reduce/change the vibration points or isolate the rider from it.
Keeping your tires and wheel assemblies in good shape is key. There are products that self-balance, such as small beads designed to be injected inside the tires. Other designs bolt directly to the wheel, looking similar to a disc rotor, they contain freely moving self-balancing mass, working on the principle. These designs, however, do not require replacement when you change your tires.
Contact point like handlebars, foot pegs and seats can all be insolated with ant-vibration designed replacement products. The handle bar’s vibration frequency can be changed by adding various weights. Or you can replace the entire handlebar with different materials and dimensions. Heavily cushioned and vibration isolating replacement footpegs and handlebar grips are widely available. Air cushioned / gel seat pads can help too.
On long trips, simply changing your position can help a lot. Try to avoid transferring the vibration into your bone structure. This means gripping the bars less aggressively, using cruise control when appropriate. Change your foot positions, use high-way pegs, or floorboards, move your seating position slightly and occasionally.
Changing speed slightly can also change the frequency and cumulative effects of vibration.
Summing it Up
Motorcycles tend to create more vibrations due to their basic design. However, keeping up with maintenance and diligently inspecting and fixing the causes of abnormal vibration will be good for you and your ride. Less vibration equals a more enjoyable experience, and very likely longer life for your motorcycle and its parts. Look for causes of vibration and ways to either eliminate or reduce the effects by changing the vibration’s frequency. Or, simply isolate the rider from the vibration as best possible.
More from New Touring Rider