Rear Derailleur Not Shifting Down! (Causes & Solutions)

Just as it is common to experience automobile issues, bicycles also suffer locomotive issues.

One major setback for our modern-day gear-bike is the issues relating to the rear derailleur.

In most cases, such issues lead to complete damage to the bike, especially when you don’t fix it. So, if your bike suffers from rear derailleur shifting problems, worry no more.

The major reason behind the rear derailleur not shifting down is a result of a broken or worn-out cassette. While in other cases, the problem results from the rear derailleur-related components. Knowing how to adjust the rear derailleur on your bike when needed will help avoid several unwanted incidents. 

3 Reasons why my Rear Derailleur is not Shifting Down?

The rear derailleur not shifting down can result from several minor reasons, but there are three major pointers.

I am bold to say that literally, every rear derailleur issue revolves around these three reasons.

#1. A Broken/Worn-Out Derailleur Cassette 

A broken or worn-out cassette is one major reason the rear derailleur is not shifting down.

A broken or worn-out cassette constantly clicks when you pedal the bike, especially when climbing a high hill.

Also, as a result of a broken/worn-out derailleur, shifting down the rear derailleur on your bike becomes difficult.

#2. Bad/Faulty Chain

Secondly, the pins and rollers connecting the chain tend to wear out as you ride your bike.

Continuous bike use under such a condition weakens and lengthens each link, leading to shifting problems.

In like manner, chain wear or stretch also results in the rear derailleur not shifting down as you’d expect.

Unfortunately, worn-out bicycle chains result in the subsequent wearing down of the derailleur cassette, especially in adverse conditions.

You will begin by noticing a few chain skips here and there before the difficulty in shifting the rear derailleur.

As little as it is, without resolving the issue immediately, you may replace the entire rear derailleur drivetrain.

#3. A Damaged Tension Cable 

Finally, a damaged housing and tension cable can be the culprit for your rear derailleur shifting problems.

More often than usual, an extreme bend or pinch on the housing will restrict the movement of the chain on the derailleur.

Also, the bend on the housing can cause the derailleur cable to become frayed, restricting the derailleur from shifting down.

The issues around the rear derailleur not shifting are numerous; your remedy is to figure out the fault.

A bent derailleur hanger is the most common issue resulting in the rear derailleur not shifting down.

Yes, there are a few other reasons why the derailleur isn’t moving down, but the above three are the commonest.

Why is Rear Derailleur Stuck in the Highest Gear?

The rear derailleur stuck in the highest gear is a basic case of derailleur hanger misalignment.

As stated earlier, most of the problems with the rear derailleur hang around the derailleur hanger.

Therefore, it is not a surprise to encounter no movement of the rear derailleur with a faulty rear derailleur hanger.

Also, the cable tension of the derailleur can be why the rear derailleur is stuck in the highest gear.

It is most likely to happen when you remove the wheels while having the chain on the smallest cog.

Tightening the cable shift of the derailleur when the chain is stuck on the highest gear (smallest cog) could be your solution.

Another simple and common reason why the derailleur gets stuck at the highest gear is because of the limit screws.

The limit screws determine the degree of the chain movement of the rear derailleur along the cassette.

So, the degree of adjustments on the derailleur from the limit screws can hinder the chains from coming down lower gears. 

Usually, every bike comes standard with two limit screws located on the derailleur body with which you can make adjustments.

The high limit screw holds the chain on the smallest cog and prevents it from falling off the rear wheel cassette.

Over-tightening the high limit screw will hinder the chain movement from the highest to the lowest gear. 

It is wise to note that faulty components relating to the rear derailleur can cause hindrances.

For instance, a sagging or bent chain will only function properly on the largest/highest cog.

In like manner, the shifting index on the handlebars may be faulty; hence no movement will be smooth.

Why is my Rear Derailleur not Shifting Down Smoothly?

It is likely a fault from the cable housing and the shifting cable at the rear derailleur.

The shift housing and cable with other components handle the smooth shifting of the chain across cogs.

Therefore, if the shifting occurs but is not as smooth as it should, the reason isn’t far from cable housing issues. 

A faulty rear derailleur hanger contributes greatly to the smooth shifting of the rear derailleur.

In like manner, a chain or cable friction can cause a kink when shifting down the rear derailleur cassette. 

However, other related components can also be the reason behind the kink in the chain movement along the cassette. 

Still, regarding rear derailleur-related components, a worn-out cassette and chain will hinder smooth shifting.

Aside from mechanical faults, sometimes, you may have too much debris between the shift housing and the shift cable.

In worst-case scenarios, it may just be that the gear adjuster or the derailleur itself is completely bad.

Sometimes, the case may be a simple issue of improper settings coming from the cable tension or derailleur limit screws.

As simple as the little adjustments seem, you cannot deny their impact on the smooth shifting of the chains.

Therefore, ensure that every component is properly checked and coupled to scale through rough rear derailleur shifting issues. 

Shimano Rear Derailleurs won’t Shift to High Gears

In cases such as such, the first thing to look out for is the derailleur limit screw settings at the back of the derailleur.

The smooth movement of the chains from one gear to another largely depends on the setting of the derailleur limit screws.

The high and low limit screw needs adjustments when the Shimano Rear derailleur won’t shift to high gears. 

More often than usual, Shimano bikes suffer from gear shifters/levers, especially in adverse conditions.

Sometimes, you need to tweak the gear shifter using a barrel adjuster or replace the gear shifter.

Experiencing such a case with the Shimano bike, you cannot get the effectiveness of the gear shifter/levers.

In addition, streaming from the gear shifter on the Shimano bike’s handlebars is the gear cable that helps movements along the rear derailleur cog.

A frayed and rusted rear cable is a headache and can prevent shifting chains to high gears.

Spraying the gear cable with a lubricant can help the smooth shifting to even higher gears.

Higher gears require more pedal energy, increasing friction on the rear derailleur, causing wear and affecting smooth gear change.

In like manner, worn-out wheel cassettes and broken chains can also cause hindrances in gear shifting.

However, the whole wheel drivetrain needs replacement if you still have issues moving to high gears.

How do I Fix a Derailleur that won’t Shift Down?

One common reason why the derailleur won’t shift down is because of wrong limit screw settings.

If the chain doesn’t shift down, tighten the high limit screw while reducing the low limit screw a bit.

Know how to set the rear derailleur limit screws to get the best experience with your gear-bike. 

To fix a derailleur that won’t shift down, get to know the reason that is causing the chain not to move.

When you effectively diagnose and figure out the problem, you will have the exact and right remedy for the case.

The table below shows a few rear derailleur issues and possible solutions.

Common Problems	Possible Solutions
A faulty gear shifter	Adjust the gear shifter using a barrel adjuster or find a replacement.
Worn-out chains and wheel cassette	Replacement is the only viable option.
Frayed gear cable or housing cable.	Try lubricating. In the worst case, replace a replacement.
A bad derailleur	You may have to replace the entire drivetrain.
Bent derailleur hanger	Go for a derailleur alignment, or better still, get a replacement.

In general, replacing the faulty parts of the rear derailleur seems to be the most viable option in some cases.

Always check and maintain your gear bike, especially the rear derailleur. As stated earlier, you can find every gear-bike part to replace at amazon or any close-by gear-bike stores.

How do I Know if my Rear Derailleur is Bad?

The rear derailleur is bad when you can no longer pedal the bike to move. At this point, after a little comparison in movement with other gear bikes, you wouldn’t need a prophet.

It will certainly begin from the normal wearing out of the derailleur down to the worst state.

It is most likely from the derailleur when you notice a consistent shifting between cogs.

A good observation of the sloppy pivot and movement within the linkage will tell you that you need a new rear derailleur.

A harsh noise as you pedal is also a point; click here to get a new rear derailleur.

However, the truth is that the rear derailleur lasts the lifespan of the geared bike itself.

Therefore, you will nearly never need to change the rear derailleur because it got bad. However, some related component damage can quickly damage the rear derailleur.

In totality, issues with rear derailleur result from many reasons, including broken chains, damaged housing and cables, and much more.

Therefore, in the instance of such related issues, it would be best to address them before the damage escalates. 

Conclusion

Gear bikes are by far the best varieties of manufactured bikes that match the demand of riders and hikers.

However, like other locomotive mediums, you are sure to run into one issue or another, most commonly rear derailleur issues.

Nonetheless, within every problem, there is a possible solution.