Di2 Rear Derailleur Not Shifting?: [3 Reasons & Solutions]

A gear combined bicycle can be very advantageous for a cyclist. On top of that, if the gear shifts automatically, the ride will be smooth. That’s what Di2 shifters provide.

Although, any difficulties regarding the shifter can be very confusing. And one of the major problems could be the di2 rear derailleur not shifting.

What to do when the di2 rear derailleur not shifting?

Firstly, an issue with the battery of the derailleur is possible. If there is no power, the rear derailleur won’t shift gears. Secondly, the crash mode might be activated which prevents gear shifting. Finally, not being upgraded to the latest firmware version can cause shifting issues.

There are various reasons but is there any solution? Well, in that case, I urge you to dive deep into this article. All of the before-mentioned issues can be solved quite easily. 

So, let’s get going!

3 Reasons Why Your Di2 Rear Derailleur Is Not Shifting

The shifting issues of the Di2 might occur because of some small reasons. Once you can locate the problems, you can fix them accordingly. 

Below, I have listed the reasons regarding the shifting issue and their corresponding solutions. 

Without further ado, let’s get into it!

Reason 1: Battery Issues

Since the Di2 is an automatic shifter, it needs a continuous power source. Accordingly, the power source is the rechargeable battery inside it.

So, naturally, the most essential component of the Di2 is the battery. If the battery is damaged or has no power, the shifting won’t be executed. The cell provides the shifters with energy and then the shifting is done on its own!

Any kind of damaged, worn-out battery can cause it not to do its job. Check out the fix for it here.

Solution

For this issue, first, you’ll have to check the battery’s health. Checking the battery health will ensure that you have a working battery. There are a lot of ways to check battery health. 

For battery testing, specifically, I use a D-FantiX battery tester. But sometimes it’s better to have a multimeter by your side. That can help you with a lot of types of testing. Because you never know what type of battery or variable you might need to test.

In that case, I rely on AstroAI Multimeter to get me over the line every time.

A healthy battery can go a long way. It shouldn’t just stop working all of a sudden. For instance, if the di2 rear derailleur battery dies overnight, replace it with a new one.

Here are two batteries that you can try out.

In theory, a di2 battery can go 2K to 5K kilometers on a full charge. If it fails to reach that much distance, change it. You can also make sure the battery is good by testing the battery.

Anyways, regularly charging any battery to at least 80% is a good habit. Apply this positive habit when you’re charging the di2 rear derailleur battery as well. It will keep the derailleur itself active, which also increases its longevity. 

Take care of the battery; in turn, it’ll take care of your machine! To charge the battery the right way, you’ll need efficient chargers.

And what is best for di2 batteries than Shimano di2 chargers. For your convenience, I’ve listed some quality chargers you can use-

Using these chargers ensures the proper charging for any batteries. Whether it is a phone battery or a di2 rear derailleur battery!

Reason 2: Activated Crash Mode

This reason is a technical one. When the Di2 rear detects any type of crash, it stops working. It’s called the “crash mode”. 

If you have encountered a crash or any type of hard-hit, this may be the problem. The derailleur goes into crash mode. The shifting is blocked because the motor doesn’t engage itself anymore.

Source: YouTube

Have a look at the solution for this below-

Solution

To solve this issue, you’ll have to reset di2 rear derailleur. There are 2 types of crash mode reset for the Di2 derailleur. The speeds differentiate between the factors in this case. 

Check 2 things before proceeding. Look for damage in the derailleur. If it is damaged, resetting it won’t do the trick. 

Additionally, check the crankset. Shifting will be easy to execute with the best gravel crankset out there. Or you might try using a Shimano shifter with the derailleur.

There are 3 types of speed of the di2 derailleur. The crash mode reset method for the 10-speed and the 11-speed derailleur is the same. The 12-speed di2 derailleur crash mode reset procedure is a bit different. 

Both methods can be considered as di2 rear derailleur adjustment. Let’s have a look-

For the 10 & 11-speed, first, find the junction box. After locating this box, you’ll observe a button on it. Press on the button for 5 seconds. Finally, a red light will flash. The flashing red light indicates that the di2 derailleur will go through all the gears. 

Source: YouTube

While it is switching gears, you have a responsibility. That is to keep spinning the cranks till all the gears of the rear derailleur are checked. After the process is done, the crash mode is reset. You can enjoy the bike ride again!

On the other hand, for the 12-speed di2 derailleur the process is not the same. First, you’ll have to stop your bicycle somewhere. Similar to the previous method, you’ll have to find the di2 rear derailleur switch.

Also, you can do it manually as well. Shift the gear to the biggest sprocket of the crank. Make the di2 rear derailleur shift up to do this. 

Cycle a bit, then lower the gear. Repeat this process until the gear is at the lowest and smallest sprocket of the bike. Don’t panic if you hear the di2 rear derailleur clicking while doing this.

These are two ways how to reset di2 shifting. If your di2 derailleur is of 10,11 or 12-speed, follow the methods above. Or you can use an 11-speed shifter with the 9-speed derailleur.

If you find the left crank arm loose when shifting the gears, fix it. It is recommended to reach out to a service center for this one. 

Reason 3: Lack of Firmware Upgrade

This is a noob mistake every bicycle rider can make regarding the di2. If you don’t upgrade the firmware to the latest version, it might have some problems. The di2 rear derailleur unable to shift is one of them. 

It is essential to keep the di2 derailleur updated. Have a look at how to do that-

Solution

The fix to this problem is pretty straightforward. You’ll need to update the firmware to its latest version to date. You can do it from a laptop or desktop. It needs to have a windows operating system installed on it.

Check for updates from the desktop or laptop. Go to the di2 manufacturing site and look for the latest update. You can search by the model of your di2 derailleur to save time. 

After finding the update, connect your bike with your computer. Thers no distinct di2 rear derailleur cable to connect it. A normal USB-C cable will do the job.

I’ve compiled some of the best USB-C cables from e-shop here-

Then you can update the firmware without any hassle. After updating, you can get the firmware version and crosscheck it with the website. If it matches, congratulations! You have the latest firmware installed on the di2 rear derailleur!

FAQs

How many years will di2 last?

If you properly charge the battery, it should run flawlessly for 11 years. Shimano claims that the battery will last 300 complete charge cycles. Taking care of the battery is also important in this process. Keep it unharmed and healthy. Don’t let the battery get too dirty. Regularly charge it.

Will Shimano 105 go 12 speed?

With the help of mechanical shifting, the Shimano 105 can go 12-speed. Shimano has no qualms about mixing 12-speed and mechanical actuation. It has been possible to reach it using mountain bikes. Although, those components have gone through some rough times. So, it shouldn’t be done regularly.

How many teeth does the biggest ring on a Shimano 12 speed cassette have?

The largest ring on the Shimano 12 speed cassette has a 10-45 tooth. It’s also a 12-speed cassette. The gear steps are very tight on this one. Generally, most bikers like the 10-51-tooth cassette option. But the 10-45 tooth option from Shimano is also worth choosing. It works pretty great!

Conclusion

I’m hoping the reasons and fixes behind your di2 rear derailleur not shifting are comprehensible. 

Before you fix the di2 derailleur, don’t put the cycle on the road. It might glitch anytime; which is unsafe for your bicycle ride. 

Wishing you all the best. Let’s get to fixing the shifter!