Handlebar wobble is not a pleasant experience, it can be just annoying to downright dangerous. Wobbles generally occur under 45 mph and are easy to get out of – just hold the bars firmly and slow down.
But weaves are different. A weave occurs at higher speeds, typically over 70 mph. The entire motorcycle oscillates around the middle. This can very easily lead to a crash if you let the amplitude increase or react abruptly by gearing down or hard braking. You can stop a weave by shifting your weight forward and down (in other words, lie down on the tank).
Do not ride a motorcycle that has any symptoms of handlebar wobble, weaving or excessive and uncommon vibration. Severe wobbles, shake or weaving is a sign something is very wrong – slow down and get off the road.
Wobble or Weave?
For this post, a wobble is the movement of the handlebars, not caused by rider inputs, that usually happens below 45 mph. A weave occurs at high speeds, at 70 and above, where the entire motorcycle feels like it is weaving underneath you. Both conditions are typically caused by mechanical issues with the motorcycle.
Do not confuse wobble, or even weave with intense vibration. Most motorcycles vibrate, especially at higher speeds and during aggressive acceleration. Excessive vibration is a symptom with different causes, I did a deep dive into vibration in this post – How Can I Fix Motorcycle Vibration?
If you find your motorcycle in a wobble, a weave or has any instability – immediately and carefully slow down and pull over, follow the checklist below…
- Check the air pressure in both tires (use an accurate gauge, not the one connected to corner garage air pumps)
- Inspect tires for bulges, sidewall stress cracks, or objects embedded in the tires. uneven tread wear, this will be an indication that there has been an issue for a long time.
- Look for loose, missing or broken parts. Has a bolt or nut is loose on the handlebars or any frontend assembly?
- Check for unevenly loaded or over-loaded saddlebags, top-box or racked cargo.
- Rear tire alignment, check the rear axle adjustments (not on shaft drives), are the same on both sides, if not the rear wheel could be cocked on the vertical plane and not tracking with the front tire.
- Is it getting worse, if so you will have to judge based on how server the wobble or weave is to either safely limp to a garage or park it & tow it?
Conditions & Symptoms
When you notice a weave or wobble appear consistently, take note of key data. Does it occur on acceleration, deceleration or both, at above 40 mph, or only at highway speeds. Does it happen with a passenger, fully loaded, or solo and no cargo?
Take note of how severe the wobble or weaving is, and if it changes with speed. Can it be repeated, is it constant regardless of road conditions. Be very cautious testing, “at speed”. There is no value in finding out the speed it “gets really bad at”, there is a problem that needs to be fixed.
Temporary issues can be caused by uneven road surfaces (rain grooved highway), winds, and traveling at higher than normal speeds, fully loaded or underloaded for suspension settings.
Both wobble and weave are serious conditions. Be aware that either can cause you to crash if not dealt with properly If you experience a wobble (low-speed handlebar gyrations), hold the bars firmly, damping the movement to keep the bike under control, and slow down, pull over and do an inspection.
For a weave, the most effective remedy is to lay down on the tank or move your torso as far forward and down as possible. This will break the dynamics of the weave. As the weave dissipates slow down, and pull over for a roadside inspection.
Troubleshooting / Causes & Fixes
For touring bikes the first places to look are tires and how your cargo is loaded.
Tire Pressure – number one, check air pressure, look for underinflation, or a significant difference between the front and rear recent changes tires. Correct tire pressure and make a habit of checking daily.
New Tire – changing only one tire, to another brand and model design can introduce instability because they are not made to work together. This mismatch should result in consistent handling problems. The fix is to replace the older tire with the same brand and model tire, so they are the same, front and back.
Another scenario is a severely worn rear tire, that has flattened from straight up street touring. Check the tire’s wear indicators. The tire may look like it has a lot of tread left, but the center may be gone. A new front tire, even from the same manufacturer and model may not be a suitable match for the rear’s flattened profile.
Tires Physical Problems – look for missing balancing weights, loose spokes or rivets in composite wheels. Look for cracking on cast wheel rims. Inspect for belt separation, this may not be visible, but you should feel a lot of vibration that will increase with speed. If rebalancing is needed, make sure the shop considers and looks for belt separation (need for excessive balance weights is a symptom).
A professional will be able to judge if interior belt separation has occurred, by the excessive amount of weights needed. Check by asking ahead of time and after the balancing.
Load Distribution – double check all your cargo, is there a mismatch of weights in the saddlebags, maybe too much weight in the top-box. Check for any loose or shifted cargo items. Try to move the heaviest items to the bottom of your saddlebags, and out of the top-box altogether.
Wheel Alignment– check that the rear wheel is not cocked and out of alignment with the front. While adjusting the final belt or chain drive the rear wheel can be moved on either side of the axle if done without measuring you can get out the rear wheel out of alignment. Depending on the motorcycle, there are usually graduated indicators to make sure you are close to being the same on each side, check these are the same first. From the rear, sight along the top of the chain or belt to make sure the run looks straight. Then measure from each side, from a common pivot point (where the swingarm attaches) to the rear axle center (a string or flexible wire works).
Suspension Settings – if you changed the rear shock(s) settings, this may have transferred forces to the front end, amplifying a problem. The front forks can be adjusted for preload (air pressure or compress internal springs) to match adjustments in the rear. Large changes to suspension settings, on one end only, then fully loading up with cargo or adding a passenger could be a contributing factor.
Hit Something – you can pump a curb or run over a pothole and not notice anything until you change speed. Take note of any incident for future reference. Inspect all related parts for impact damage.
High Miles – motorcycles simple get old and handle less precise over time. Bearings and bushings, fork springs and related parts wear and wear out over time. There could be worn bearings in the front end, or bushing in the swing arm bushings, rear end, driveline or even motor mounts. Since this is gradual you may not notice until handling issues startup. Start on the front end and do a complete inspection of all rotating and moving parts. It might not be just one part, the total of all worn components could be the cause also.
Accessories – suspect anything added to the “front end”, this means anything that is attached to the moveable front wheel-fork-handlebars assembly. A new fork-mounted windshield is an obvious suspect, but things like a drink holder or smartphone clamp can have odd effects on handling. Large items strapped t the rear could cause changes to the center of gravity or aerodynamics enough to start problems.
Storage – if the bike has recently been brought out of storage or has been parked for an extended time (over 2 weeks). Sitting may have deformed the tires, especially if the bike was left resting on both tires. Riding for 200-300 miles should return the tires to their proper shapes.
Underloading – a motorcycle that is underloaded for its basic design can be a problem. A larger bike with a lighter rider can develop weave. The fix is to add more weight.
Novice Skills – low-speed wobble can be induced by the rider. If the rider is not confident they can instinctively move the handlebars too much. Thye over correct and can create a wobble. More practice, at slower speeds, is needed.
Summing it Up
Under normal conditions, and at legal highway speeds and with a properly maintained motorcycle weave and wobble should be a very rare problem. The majority of the causes can be traced to tires, excessive speed, and uneven loading and weight distribution, and tires. By following the checklist above you should be able to identify and correct the problems.
- What is a Steering Damper?
A steering damper is mounted to the front forks or the triple-tree of a motorcycle. The damper applies a small amount of friction over the range of handlebar movement. The damper is adjustable and lets you set a constant amount of friction to dampen handlebar movements. When set correctly a steering damper is not noticeable to the rider but it does remove some of the bar movement. Dampers are not used on sport bikes and some larger off-road machines. Do not look for a damper to solve basic steering problems, fix the core issue first.
- What is a Front Fork Brace?
This brace is designed to make the front end fork assembly less prone to flexing. The one-piece brace clamps on to each sliding section of the fork tubes. The brace solidly connects the lower tubes together just above the front tire. This strengthens the front end reducing flexing and improving overall handling. Fork braces are typically used on high-performance applications that push the motorcycle to its maximum limits.