8 Reasons Why Bike Gear Slipping Happens

a young lady stands besides her ebike near the fence

Cycling your e-bike has been one of the most exhilarating experiences as it lets you exhale and exercise simultaneously. It has been getting you away from the drudgery of life and giving you a spring in your step. But something is amiss.

You started having issues with gear slipping some time ago. Initially, it was a slight irritation, but it has turned out to be a full-blown headache as it takes away the joy of e-bike riding. Your rides have become rough, challenging, and even dirty as you try to resolve the bike gear slipping issue.

This article lists the eight most probable causes for gear slipping (also called gear skipping) in bikes. It will also give you solutions to resolve this issue so you can go back to enjoying your e-bike rides. But first, understand some of your bike parts and their names, as you will need this knowledge.

Parts Of Your Drivetrain

Your drivetrain is a combination of parts that enable your physical input to be converted to a movement that propels the bicycle forward. This drivetrain consists of chains and pedals, which almost everyone knows off the top.

But beyond these well-known parts are other parts that enable converting your power into movement. The chain moves along two main parts; the chainrings held between the crankarms you move with the pedals and the cassette fastened to the rear wheel hub.

drivetrain of electric bike

The chainrings and the cassette have teeth that the chain clips on through its links and moves the rear wheel forward. The chainring can be just one plate, or if it has front gears, have two to three chainrings connected. Most modern bikes have gotten rid of the front gears in favour of one chainring.

The cassette attached to the rear wheel can have five or more sprockets (the name of an individual gear plate).

Beyond these five main parts, you have the front and rear derailleurs that make up the drivetrain. The work of the derailleur is to shift the chain and shift it to the specified gear. The front derailleur is present in bicycles with front gears and moves the chain to the chosen chainring. A bicycle that does not have front gears will also not have a front derailleur.

A rear derailleur serves the same purpose as a front derailleur but derails the chain to the specified sprocket on the cassette.

Reasons Why Bike Gear Slipping Happens

Now that you have acquainted with your bike parts, let’s dive into what could cause bike gear slipping issues.

chain of electric bike

A Loose Chain

A loose chain is one of the easiest culprits to find that causes gear slipping. It is also the easiest to resolve. A loose chain can come from a newly installed chain that stretches as it adjusts to the tension. You can efficiently resolve such a problem as you do not need to replace any parts.

Gear Indexing Misalignment

Another issue closely related to a loose chain is a gear indexing misalignment. And one of the causes of gear indexing misalignment is a loose chain. A barrel adjuster could also be loose, causing this issue.

A barrel adjuster alters the distance a bicycle cable has to travel. A bicycle has several cables, including the brake, gear, callipers, and derailleur cables.

A Worn Chain

A worn-out chain can also give rise to gear skipping. The chain could have stretched beyond the norm due to prolonged intensive use. The plates and rollers could have worn out, making the chain lose contact with the sprockets and chainring teeth.

A downside to a worn-out chain is that it will wear out the chainrings and sprockets if not resolved quickly.

hub motor of electric bike

Worn Chainring And Sprocket Teeth

A worn-out chain can still work on the e-bike. But the longer it stays there, the more it damages other drivetrain parts. The chainring connected to the pedals with the crank arm and the sprockets attached to the rear wheel will all get worn teeth.

The longer you stay with a worn and overused chain, the higher the chances you will wreak other drivetrain components.

Wrong Spare Replacements

Like in vehicles and all other machinery, every machine has specific spare parts that fit it. If you replace your drivetrain parts with the wrong ones, you will have the chain slipping. For example, buying a chain with wider plates than required will have it slipping off the sprockets and chainrings.

A Dirty Drivetrain

A dirty drivetrain is one of the common troubles that can cause bike gear slipping issues. It may look like a straightforward issue. And it is a simple yet overlooked issue. If you haven’t cleaned your bicycle yet, use it constantly in a while, and then you need to observe how much grime and sludge buildup is on the drivetrain.

Shifting System Error

The shifting system could also blame for bike gear slipping issues. The shifting system comprises several parts, including the rear derailleur, the shifter, cable, and the derailleur hanger.

The derailleur can lose its alignment, while its hanger, which is made malleable, can easily get shifted upon impact or too much tension. A poor-quality shifter can lose its tautness to keep the shifter cable taut, derailing the chain. Similarly, a shifter cable can also lose its elasticity, becoming loose and causing the gear to slip.

Spoilt Freehub

The freehub is a part of the rear wheel hub that interacts with the drivetrain to cause the rear wheel to propel the bicycle forward. It gets engaged every time you pedal and disengages the moment you stop pedalling. You can hear it make that constant whirring sound when you are not pedalling but moving forward.

A spoilt freehub or freehub shell can cause the wheel hub to lose momentary contact with the drivetrain, causing bike gear to slip. While freehubs can last a long time, it might be worth looking into if all the above possibilities have not borne fruit.

rear hub motor of electric bike

How To Fix Bike Gear Slipping

Fixing the bike gear slipping issues is most important if you keep enjoying your cycling and retain your bicycle at its best. You can try and troubleshoot some of the more straightforward issues stated above, while you may need the help of a bicycle mechanic for the more complex issues. Here are the fixes to the issues stated above:

Tighten Or Loosen The Chain

A loose chain has a simple solution of tightening it to increase its tension and keep it put when moving across the sprocket and chainring teeth. A taut chain can also cause gear slipping, so ensure you keep the chain with enough give and not too tight or loose.

Tighten The Barrel Adjuster

Since the gear cable could be loose, causing the slip, you can check the barrel adjuster and tighten it to shorten the distance the cable travels.

Replace Worn Parts

Worn parts could include the bike chain, chainring, cassette, and freehub, among other parts. Doing proper diagnostics will tell you which part or parts need replacing. Remember that replacing worn parts as soon as you discover them prevents other parts from getting damaged by worn parts.

Replace Wrong Parts

The same applies if you bought the wrong bike parts. If you realize you have bought the wrong parts early on, you can always try and get them exchanged with the correct parts from the spare parts shop. If the exchange is impossible, count it as a loss and replace those parts with the correct ones.

Clean The Drivetrain

Cleaning the drivetrain is another correction you can make to your bike right home. You must ensure liquid dishwashing soap, clean water, and two to three available rugs.

You can clean the bike thoroughly, focusing on the drivetrain and ensuring that you have gotten the grime you can out. You can use a small flat-blade screwdriver to scrape the grime buildup out.

You can let the bike dry thoroughly, wrap the chain in a dry rug, and slowly take it through the rug as you move it with pedal movement.

Seek Expert Help

Finally, if you feel there are things you cannot do by yourself, be sure to seek expert help. If your bike still has an active warranty, you can contact the shop that sold you the bicycle.

bicycle repairer is fixing the bike gear slipping issues


Your comfort is of utmost importance when out riding. Bike gear slipping issues can affect your enjoyment. You can enlist the help of expert bike mechanics to assist you in resolving these issues quickly and in a professional manner. Check out Eskute for the best e-bikes in the UK and Europe and expert assistance.

Leave a comment

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Reading next

hardtail electric bike in the farmland
A lady sits on her electric hybrid bike in front of buildings