What Are Common Derailleur Problems? Complete Guide for Cyclist

If you have ever hopped on your bike and noticed that your gears feel sluggish, your chain is skipping, or your shifting sounds like something is grinding inside the drivetrain, there is a very good chance the derailleur is involved.

The derailleur is the mechanism responsible for moving your chain from one gear to another, and it is one of the hardest working parts on your entire bike.

When it develops a problem, everything about riding feels harder and less enjoyable.

This guide is built on established bicycle mechanics principles trusted by professional technicians and experienced riders across the United States.

Whether you are a casual weekend cyclist, a daily commuter, a mountain biker, or a road racing enthusiast, understanding common derailleur problems will help you diagnose issues faster, fix them more confidently, and prevent them from returning.

Every explanation here is written in clear, straightforward language so that riders of every age and experience level can understand and apply the information without needing a mechanical background.

By the time you finish reading, you will know what every major derailleur problem looks like, what causes it, how to fix it, and when to seek professional help from your local bike shop. Let us get into it.

What Does a Derailleur Actually It Matter?

Before diving into problems and fixes, it helps to understand what the derailleur actually does. Most modern bikes have two derailleurs. The rear derailleur moves the chain across the cassette, which is the cluster of cogs on your rear wheel. The front derailleur moves the chain across the chainrings, which are the large rings attached to the crank where your pedals attach.

Each derailleur is controlled by a cable that runs from a shifter on your handlebars to the derailleur body. When you click the shifter, it either releases or pulls a precise amount of cable. This cable movement pushes or allows the derailleur to swing inward or outward, which physically lifts the chain from one cog or chainring to another.

The entire system depends on precise mechanical alignment. The cable must have exactly the right tension. The derailleur must sit at exactly the right angle. The limit screws must stop the derailleur at exactly the right points. The chain and cogs must be in good enough condition to hold the chain reliably. When any one of these elements is even slightly off, problems appear.

Understanding this chain of cause and effect, where one small misalignment causes a noticeable symptom, is the foundation of effective derailleur troubleshooting.

The Most Common Derailleur Problems

Derailleur problems almost always fall into a predictable set of categories. Knowing which category your problem belongs to points you directly toward the right solution without wasting time on unnecessary fixes.

Improper cable tension is the single most common derailleur problem on bikes of every type and price level. Cables stretch naturally with use, especially during the first few weeks after a new bike is purchased or after fresh cables are installed. As the cable stretches, it loses the precise tension needed to position the derailleur accurately. The result is shifting that feels hesitant, gears that do not engage cleanly, or a chain that slips when you push hard on the pedals.

A bent derailleur hanger is the second most common problem and one that many riders overlook entirely. The hanger is a small replaceable piece of aluminum that connects the rear derailleur to the bike frame. It is designed to bend in a crash rather than allowing the frame or derailleur to absorb the impact. Even a fall at low speed, or simply bumping the bike against a wall or car, can bend the hanger enough to cause significant shifting problems.

Incorrect limit screw settings cause the chain to travel too far in either direction, leading to the chain falling off the cassette entirely or being unable to reach the easiest or hardest gears. This is particularly dangerous when the chain falls toward the spokes on the largest cog side.

Dirty, corroded, or worn cables and housing create friction inside the system. Instead of moving freely when you click the shifter, the cable drags against the inside of the housing. This makes shifting feel heavy, slow, and inconsistent.

A worn chain or cassette means the mechanical interface between the chain and the cogs has broken down. Worn teeth and stretched links no longer mesh correctly, causing the chain to skip over teeth under pedaling pressure instead of locking in cleanly.

A misaligned front derailleur causes chain rub, poor shifting between chainrings, and dropped chains. Height, angle, and limit screw settings all affect front derailleur performance.

Worn or damaged derailleur pivot points and jockey wheels introduce mechanical slop into the system. Even when cable tension and alignment are correct, a derailleur with worn pivots cannot position the chain with the precision that smooth shifting requires.

How to Recognize Derailleur Problems

Your bike communicates derailleur problems through specific symptoms. Learning to read these symptoms correctly is the difference between fixing the right thing immediately and spending time adjusting components that are not actually causing the issue.

Chain skipping or jumping between gears is one of the most noticeable symptoms. The chain appears to shift on its own without you touching the shifter, or it skips forward with a lurch when you pedal hard. This points to cable tension problems, chain wear, cassette wear, or a combination of all three.

Slow or hesitant shifting means that when you click the shifter, the chain takes a moment to move or does not move at all on the first click. This is the classic symptom of stretched cables or dirty housing that is creating excessive friction on the cable.

Excessive noise from the drivetrain including clicking, grinding, rattling, or rubbing sounds while pedaling suggests the chain is not sitting cleanly on the intended cog. This can mean indexing is off, the front derailleur is rubbing the chain, or the drivetrain components are worn.

Chain dropping off the smallest or largest cog means the limit screws are allowing the derailleur to travel too far in that direction. The chain ends up somewhere it was never meant to go.

Shifting works on one end of the cassette but not the other is a very specific symptom that almost always points to a bent derailleur hanger. Because the hanger angles the derailleur away from its correct plane, it may align reasonably well with cogs at one end of the cassette while being significantly off at the other end.

Shifting that was fine but suddenly got worse after a fall or impact is a strong indicator that the derailleur hanger bent during the impact, even if the bike looks perfectly normal from the outside.

Use this reference table to match your symptom to the most probable cause:

1. How to Fix Improper Cable Tension

Cable tension is the first thing to address whenever shifting feels off. The adjustment process takes less than five minutes and requires no tools at all. The component you use to make this adjustment is the barrel adjuster.

The barrel adjuster is a threaded cylindrical dial located where the cable enters the rear derailleur. Many bikes also have a second barrel adjuster where the cable exits the shifter at the handlebars. Both do the same job and you can use either one.

Understanding how the barrel adjuster works:

When you turn the barrel adjuster counter clockwise, meaning the top of the dial rotates away from the derailleur, you effectively increase the length of the housing between the derailleur and the next cable stop. This pulls the cable tighter without moving the anchor point, which moves the derailleur slightly toward the larger cogs. When you turn it clockwise, you decrease housing length, which releases cable tension and allows the derailleur to move toward smaller cogs.

The adjustment process:

Start by shifting to a middle gear in the cassette range, typically the third or fourth cog from the smallest. This gives you a reference point that is easy to evaluate. While pedaling with the rear wheel off the ground, listen and watch for the chain to sit cleanly and quietly on the cog without hesitation.

If the chain hesitates when shifting to larger cogs or feels like it is being pulled back toward smaller cogs, turn the barrel adjuster counter clockwise by half a turn and test again. If the chain overshoots toward larger cogs or sits slightly too far inward, turn it clockwise by a quarter turn and test.

The goal is to hear and feel the chain shift cleanly to exactly one cog with each click of the shifter, with no noise, no hesitation, and no tendency to wander between clicks.

Cable Tension Quick Reference

If the barrel adjuster reaches its maximum extension and shifting is still not correct, the cable has stretched too far to be adjusted by the barrel adjuster alone. At this point, the cable needs to be re anchored at the derailleur clamp bolt, which is covered in a later section.

2. Diagnosing and Fixing a Bent Derailleur Hanger

A bent derailleur hanger causes some of the most confusing and persistent shifting problems in cycling because it mimics other issues. Riders often spend significant time adjusting cable tension and limit screws when the real problem is a hanger that is bent by just one or two millimeters.

Why the hanger bends so easily:

The hanger is made from relatively soft aluminum on purpose. It acts as a sacrificial component. In the event of an impact, the hanger absorbs the force and bends rather than allowing the energy to reach the frame or the derailleur body. This design protects much more expensive components, but it also means the hanger can bend from surprisingly minor impacts.

How to identify a bent hanger:

Stand directly behind the bike at wheel level and look at the rear derailleur. The entire derailleur body, including the jockey wheels, should sit in a perfectly vertical plane that is parallel to the wheel and the cassette. If the derailleur leans visibly inward toward the wheel or outward away from it, the hanger is bent.

A more reliable way to identify a bent hanger is to pay attention to how the shifting behaves across the full range of the cassette. A bent hanger causes the derailleur to be closer to the correct alignment at one end of the cassette and progressively more misaligned toward the other end.

Adjusting cable tension to fix shifting on the large cogs then breaks shifting on the small cogs, and vice versa. This endless cycle of adjustments that partially help but never fully fix the problem is the strongest diagnostic indicator of a bent hanger.

The fix:

A derailleur hanger alignment tool is the correct instrument for this repair. A mechanic threads the tool into the derailleur hanger mounting point and uses its long arm to measure the distance between the tool tip and the rim at multiple points around the wheel.

Any deviation reveals the direction and degree of the bend. The mechanic then carefully applies measured force to the hanger to bring it back into alignment.

Most bike shops across the United States offer hanger alignment as a quick service, typically costing between $10 and $25. If the hanger is severely bent, or if it has been bent and straightened multiple times before, replacement is the safer choice.

Hangers are frame specific, meaning you need the one designed for your exact bike model. They are generally available online or through your local bike shop for $10 to $30.

Attempting to straighten a hanger by hand or with improvised tools is not recommended. Uneven pressure can weaken the aluminum in ways that are invisible to the eye and may cause the hanger to snap during a ride.

3. How to Set Limit Screws Correctly

The limit screws are two small screws on the rear derailleur body, usually labeled H and L. They are the physical stops that define how far the derailleur can travel toward the smallest cog and toward the largest cog. When these are set incorrectly, the consequences range from annoying to genuinely dangerous.

Setting the H screw (high gear limit):

Shift to your smallest rear cog and smallest front chainring. This is your highest gear combination. Look at the rear derailleur from behind the bike.

The upper jockey wheel should sit directly below the smallest cog with no inward or outward offset. If the jockey wheel sits slightly outboard of the smallest cog, the chain may fall off the outside of the cassette during riding.

Tighten the H screw clockwise by a quarter turn at a time until the jockey wheel is correctly aligned.

If the chain struggles to reach the smallest cog during shifting, the H screw is too tight and is physically preventing the derailleur from traveling far enough. Loosen it counter clockwise by a quarter turn and test again.

Setting the L screw (low gear limit):

Shift to your largest rear cog and largest front chainring. This is your lowest gear combination and the one that is most important to get right from a safety standpoint. The upper jockey wheel should sit directly below the largest cog. If the derailleur can travel past this point, the chain may fall off the inside of the cassette and into the spokes, which can lock the rear wheel suddenly.

Tighten the L screw clockwise until the derailleur stops precisely at the largest cog position. If the chain cannot reach the largest cog during shifting, loosen the L screw counter clockwise by a quarter turn and test.

Limit Screw Settings Reference

4. How Dirty and Worn Cables Cause Shifting Failure

The cables and housing on your bike are the communication pathway between your shifter and your derailleur. When this pathway develops friction or physical damage, the precision of the entire system breaks down even if the derailleur itself is in perfect condition.

How cable housing degrades:

Cable housing is made from a coiled or compressed metal inner structure wrapped in plastic. Over time and exposure to weather, the inner lining of the housing degrades, develops rough spots, and loses the smooth surface that allows the cable to slide freely. Additionally, water can enter the housing at the ends and cause the cable wire itself to corrode, which creates even more friction.

From the outside, housing often looks perfectly fine long after it has degraded internally. This is why replacing cables and housing on a regular schedule rather than only when they visually appear damaged is good preventive practice.

Signs that cables or housing need replacement:

• Shifting feels heavy or requires more force than usual at the shifter lever
• The derailleur moves sluggishly or incompletely even after cable tension adjustment
• Ghost shifting occurs despite correct cable tension
• Visible kinking, crushing, or cracking in the outer housing
• Any fraying visible at the cable ends where they exit the housing
• Corrosion or rust visible on the cable wire itself

The fix:

Cable and housing replacement is one of the most straightforward maintenance tasks on a bicycle. A complete rear cable and housing set costs between $10 and $25 for standard components. Higher quality stainless steel cables and compressionless housing, which is housing that resists compression under cable tension for more precise shifting, costs more but makes a noticeable difference in shifting feel.

Most bike shops complete a cable and housing replacement in 30 to 45 minutes. Many experienced home mechanics do this themselves using basic tools. Either way, fresh cables and housing transform the feel of a drivetrain that has been working with degraded components.

For regular riders, replacing cables and housing once a year is a sensible maintenance interval. For commuters who ride in wet or winter conditions, more frequent replacement may be warranted.

5. Recognizing and Addressing Worn Chain and Cassette

No amount of derailleur adjustment will fix slipping or skipping that comes from a worn chain and cassette. Understanding wear, how to measure it, and when to replace components is essential knowledge for any cyclist.

How chains wear:

A chain is made up of hundreds of individual links, each consisting of inner and outer plates connected by pins and rollers. As you ride, the rollers wear slightly at their contact points with the cassette teeth and chainring teeth. This wear causes the effective length of each link to increase slightly. Over thousands of pedal strokes, this adds up to a measurable stretching of the overall chain length.

A stretched chain no longer meshes correctly with the teeth it was designed to fit. Instead of the rollers dropping cleanly into the valleys between teeth, they ride up on top of the teeth under pedaling load and then skip forward. This is chain skip, and it becomes more pronounced the harder you pedal.

How to measure chain wear:

A chain wear indicator tool, available for $5 to $15 at any bike shop or online, measures this stretch precisely. Insert the tool into the chain while it sits on the bike. If the tool drops to the 0.75 mark or beyond, the chain has stretched past the point where it should be replaced. Replacing at 0.75 rather than waiting until the chain reaches 1.0 wear is important because a chain worn to 0.75 has already begun accelerating cassette wear. A chain worn to 1.0 has likely caused significant cassette damage.

Cassette wear:

Look at the cassette teeth from the side. Healthy teeth appear symmetrical, with a gently rounded profile on both leading and trailing edges. Worn teeth develop an asymmetrical shape often described as shark fin teeth, where one edge hooks forward while the other falls away more steeply. These hooked teeth grab the chain during the power stroke and release it suddenly, which is what causes the lurching, skipping sensation under hard pedaling.

The replacement rule:

Always evaluate the cassette when replacing the chain. If you install a new chain on a significantly worn cassette, the new chain will skip immediately because it does not fit the hooked tooth profile that the old chain had worn into the cogs. Replace the chain and cassette together whenever both show significant wear. This is more economical in the long run than replacing the chain alone and then discovering the cassette is too worn to work with a new chain.

Chain and Cassette Wear Reference

6. Front Derailleur Misalignment and How to Correct It

The front derailleur controls chain movement between your chainrings, typically from the small ring to the large ring on a two chainring setup. Misalignment of the front derailleur is a very common problem that causes chain rub, dropped chains, and poor shifting between rings.

Height misalignment:

The front derailleur cage should sit approximately 1 to 3 millimeters above the tallest teeth of the large chainring when viewed from the side. If it sits higher than this, shifting performance suffers because the cage does not guide the chain with enough precision. If it sits lower, the cage teeth may contact the chainring teeth directly, which causes noise and prevents the derailleur from moving freely.

To adjust height, loosen the band clamp or braze on bolt that secures the front derailleur to the frame and slide it up or down to the correct position before retightening.

Angle misalignment:

Looking down from above, the outer plate of the front derailleur cage should run parallel to the chainrings. If the cage angles inward or outward, the chain is pushed at a diagonal rather than straight across, which causes rubbing, hesitant shifting, and dropped chains. Correct the angle by loosening the mounting bolt slightly, rotating the derailleur to the correct position, and retightening.

Cable tension on the front derailleur:

The front derailleur also uses a barrel adjuster for cable tension, typically located at the handlebar shifter for the front. If the chain rubs on the inner cage plate in the large chainring and large rear cog combination, or on the outer cage plate in the small chainring and small rear cog combination, a small cable tension adjustment often resolves the issue. Additionally, avoiding these extreme cross chain combinations entirely is good practice because they place excessive lateral stress on the chain.

7. Worn Pivot Points and Jockey Wheels

Even when cables, hangers, and limit screws are all correct, a derailleur with worn pivot points or jockey wheels cannot shift with precision. This is a less commonly discussed problem but one that becomes relevant on older bikes or those ridden very heavily.

Worn pivot points:

The rear derailleur body pivots on two spring loaded joints that allow it to swing inward and outward as cable tension changes. Over thousands of shifts, these pivot points develop play, meaning small amounts of looseness in the joint. This looseness allows the derailleur to move slightly in directions it should not, making precise chain placement on individual cogs impossible even with perfect cable tension.

You can check for pivot wear by holding the derailleur body and trying to move it side to side without pressing the spring. Any lateral movement beyond a very small amount indicates worn pivots. A derailleur with significantly worn pivots generally needs replacement rather than repair, as the pivots are not user serviceable on most models.

Worn jockey wheels:

The jockey wheels, also called pulley wheels, are the two small plastic or ceramic wheels on the rear derailleur that guide the chain. The upper jockey wheel, called the guide pulley, positions the chain laterally over the correct cog. The lower jockey wheel, called the tension pulley, maintains chain tension.

Worn jockey wheels develop play on their axle, become oval shaped from uneven wear, or lose teeth. Any of these conditions reduces the precision with which the chain is guided. Replacing jockey wheels is simple and inexpensive. Most sets cost between $5 and $30, and the replacement process involves only removing two bolts. Higher quality ceramic bearing jockey wheels are available for $30 to $80 and offer reduced friction and longer service life.

How Long Does a Derailleur Last and Replace It?

A derailleur is a durable component that can last many years when it is properly maintained and not subjected to significant impacts. The typical rear derailleur on a well maintained recreational or commuter bike can last 10,000 miles or more. However, several factors can shorten this lifespan significantly.

Signs that a derailleur needs replacement rather than adjustment:

• The derailleur body is visibly bent from a crash impact that bent the hanger and the derailleur together
• Pivot points have significant play that cannot be resolved by any adjustment
• The parallelogram linkage, which is the four bar mechanism that keeps the jockey wheels parallel to the cassette, is bent or damaged
• Jockey wheel teeth are worn to the point of being rounded off and replacement wheels are not available for the model
• The derailleur cage is cracked or bent
• Shifting is sloppy and imprecise despite correct cable tension, a straight hanger, and good chain condition

Derailleur replacement cost:

Entry level replacement derailleurs cost between $20 and $50. Mid range options from brands like Shimano and SRAM in the $50 to $150 range offer significantly better shifting performance and durability. Higher end components can cost $200 or more. For most recreational riders, a mid range replacement derailleur provides an excellent balance of performance and value.

Complete Derailleur Troubleshooting Checklist

Use this systematic checklist whenever you experience derailleur problems. Working through it in order ensures you address the simplest possible cause first before moving to more involved solutions.

Step one: Adjust cable tension with the barrel adjuster. Turn counter clockwise by half a turn and test shifting. This resolves the majority of derailleur problems.

Step two: Clean and lubricate the chain. A dirty, dry chain causes symptoms that mimic indexing problems. Clean the drivetrain thoroughly before making further adjustments.

Step three: Check chain wear. Use a chain wear indicator. Replace the chain if it reads 0.75 or beyond.

Step four: Inspect the cassette. Check for hooked teeth. If present, replace cassette and chain together.

Step five: Inspect the derailleur hanger. Look from behind the bike for any visible lean. If shifting works on one end of the cassette but not the other, have the hanger professionally aligned.

Step six: Check limit screws. Verify H and L screw settings by testing in the highest and lowest gear positions.

Step seven: Inspect cables and housing. Look for kinks, cracks, or fraying. Replace if any damage is found.

Step eight: Check jockey wheels. Spin each wheel by hand. Replace if wobbly or significantly worn.

Step nine: Evaluate the derailleur body. Check pivot points for play and the cage for damage. Replace the derailleur if significant wear or damage is found.

How to Keep Your Derailleur Working Perfectly

Most derailleur problems are preventable with a simple and consistent maintenance routine. These habits take very little time and significantly extend the life of all drivetrain components.

• Clean and lubricate the chain every 100 to 150 miles under dry conditions or after every wet ride. A clean chain transmits shifting forces cleanly and wears far more slowly than a dirty one.
• Replace the chain at 0.75 wear rather than waiting for it to cause cassette damage. This is the single most impactful maintenance decision a cyclist can make for long term drivetrain health.
• Inspect the derailleur hanger after any fall or impact even if the bike appears undamaged. Getting the hanger professionally aligned immediately after a crash prevents the frustrating shifting problems that develop when a bent hanger goes unnoticed.
• Replace cables and housing annually for recreational riders, or more frequently for commuters who ride in wet or winter conditions.
• Shift gently rather than under heavy load. Try to ease up briefly on pedaling pressure when shifting, especially on climbs. Shifting under maximum load accelerates wear on cables, cassette teeth, and the chain itself.
• Rinse the drivetrain after riding in rain or mud and dry it before applying fresh lubricant. Water displaces lubricant and accelerates corrosion on cables and chain links.
• Get a professional tune up once a year. A skilled bike mechanic can identify developing problems before they become serious and perform adjustments that are difficult to accomplish at home without specialized tools.

Frequently Asked Questions About Derailleur Problems

What are the symptoms of a bad derailleur?

A derailleur that needs attention typically shows one or more of the following: chain skipping or jumping during pedaling, slow or hesitant shifting when you click the shifter, grinding or clicking noise from the drivetrain, chain dropping off the cassette at the extreme gears, or shifting that works correctly on some gears but not others. Any of these symptoms warrants investigation before the next ride.

Why is my derailleur not shifting smoothly?

The most common reason is stretched cable causing incorrect indexing. Try turning the barrel adjuster counter clockwise by half a turn and testing. If this does not help, inspect the chain for wear, check the derailleur hanger for bending, and look at the cable housing for damage or compression. Smooth shifting requires all of these elements to be in good condition simultaneously.

What is the lifespan of a derailleur?

A quality rear derailleur that is well maintained and not subjected to significant impacts can last 10,000 miles or longer. Lower quality components wear more quickly. The most common reason for early derailleur replacement is crash damage to the hanger and derailleur together, not gradual wear from normal use.

How do I tell if my rear derailleur is worn out?

Check for these specific indicators: the parallelogram linkage feels loose or sloppy when you move the derailleur by hand without cable tension, the jockey wheels wobble significantly or have lost their teeth, the pivot points have measurable side to side play, or the cage is bent or cracked. If shifting remains poor after correcting cable tension, replacing the hanger, and installing a fresh chain and cassette, the derailleur itself may have worn beyond the point where adjustments can compensate.

Can I fix a bent derailleur hanger myself?

You can, but only if you have a derailleur hanger alignment tool, which costs approximately $30 to $60. Without this tool, attempting to straighten the hanger by hand or with improvised tools creates uneven stress that can weaken the metal and cause it to snap during a future ride. Most riders find it more practical to have a local bike shop perform the alignment for $10 to $25 or simply replace the hanger for $10 to $30.

How much does it cost to fix derailleur problems?

Most derailleur problems are inexpensive to fix. Cable tension adjustment costs nothing. A chain replacement costs $20 to $60. Cassette replacement costs $25 to $120. Hanger alignment runs $10 to $25 at a shop. Full cable and housing replacement costs $10 to $25 for parts plus labor. A complete drivetrain overhaul including chain, cassette, cables, and housing typically runs $80 to $200 for parts, with labor adding $50 to $100 at most shops.

When to Visit Your Local Bike Shop for Derailleur Problems

Many derailleur problems are genuinely manageable at home with basic tools and patience. However, certain situations call for professional expertise and specialized equipment.

Visit your local bike shop when barrel adjuster adjustments do not resolve shifting problems after several careful attempts, when you suspect a bent derailleur hanger and do not own an alignment tool, when cables need replacement and you are not comfortable with the process, when the derailleur body appears physically damaged from a crash, when a new chain causes immediate skipping suggesting a worn cassette, or when the bottom bracket feels rough or loose as this sometimes creates symptoms that are mistaken for derailleur problems.

Bike shops across the United States are welcoming community spaces where mechanics genuinely enjoy helping cyclists understand their equipment. A good shop will explain what they found and what they fixed so that you understand your bike better after every visit.

Final Thoughts

Derailleur problems are among the most common mechanical issues cyclists face, but they are also among the most understandable and fixable. The vast majority of cases come down to a small number of root causes: cable tension that needs a quick barrel adjuster correction, a dirty or worn chain, a bent hanger, or limit screws that need minor refinement. Work through these systematically and you will resolve almost every derailleur issue you ever encounter.

The deeper lesson here is that your derailleur is always communicating with you through the way it shifts. Learning to read those signals, connecting the symptom you feel to the cause behind it, transforms you from a frustrated rider guessing at solutions into a confident cyclist who understands exactly what is happening and exactly how to fix it.

Regular maintenance prevents most of these problems before they develop. Clean the chain, replace it on schedule, keep cables fresh, and check the hanger after any impact. These habits take very little time but make an enormous difference in how reliably and quietly your bike performs every single ride.

Take care of your derailleur and it will reward you with smooth, precise, confident shifting through every gear, on every terrain, for thousands of miles to come.