All language subtitles for Shimano Nexus 3 Gang schaltet nicht - Nabenschaltung reparieren - English (United States)

[automatic translation] Is your Nexus three-speed hub gear not shifting properly, making a clicking noise, or slipping? In this

video, I'll show you the most common problems that cause shifting issues and teach you

how to fix them yourself. The diagnostic process is

the same for all Nexus three-speed hub models, and I'll briefly explain the most important points for each.

If you need more detailed videos on most of the problems, you can find them and

everything else in the video description and in the Nexus three-speed hub playlist. First, two things

that are completely normal and not considered faults. It's normal for

the Nexus three-speed hub to make clicking noises while riding and in neutral.

This clicking is perfectly normal during operation, so there's no need to worry. It's also normal

for the gear to stick when you pedal and downshift simultaneously. The

gear will stick until you stop pedaling, at which point you'll hear a short click

as the gear engages properly.

If you hear a cracking or creaking noise while riding, or if the pedals briefly lose traction, the

first thing to check is whether the noise is related to the chain and sprockets.

Often, people think the derailleur is faulty, but the chain is simply skipping a tooth on the sprocket under load

, causing the cracking noise. This can be caused by a

chain that is too loose, which then vibrates excessively while riding, causing a tooth to skip or

even come off completely. With internal gear hubs, this loose chain can be relatively easily tightened

to solve the problem. Alternatively, the chain and sprockets might be too worn,

and the chain no longer stays properly on the sprockets, skipping

a tooth under heavy load. This also produces a cracking noise. If this is the case,

the chain and sprockets should be replaced. Secondly, we check whether the derailleur is adjusted

correctly. It's possible that the setting can change on its own over time

, for example, because the shift cable has stretched. If we

look into this viewing window on the clickbox at the rear wheel, we see this yellow mark inside when shifting gears

. In second gear, the yellow mark should be between these two white lines

for the derailleur to be correctly adjusted. If, as in this case, it isn't,

you can change the position of the yellow mark by turning this adjustment screw

here. Before adjusting it, you must first

loosen this lock nut here with a 10mm open-end wrench. You can find a detailed explanation of how to adjust the derailleur in the first

video, in the video description. What to do if you can't get the yellow mark between the white lines at all after adjusting

the screw is explained in the last

section of this video. However, even a correct derailleur setting can be deceptive.

It can certainly look as if the derailleur is correctly adjusted and everything seems

to be shifting. In that case, the clickbox simply isn't seated correctly on the axle. Often, the

clamping screw on the side isn't tightened properly, or its threads are stripped.

When shifting, the clickbox then pushes slightly away from the axle instead of

engaging the gear. If the clickbox has pushed away and you then adjust the derailleur,

everything may appear to be correctly adjusted, but the shifting still won't work, even though the yellow

mark is between the two white lines. Therefore, if you

can still move the clickbox despite the clamping screw being tightened, you definitely need to replace it. It's

also possible that the clickbox is secure but can't be pushed far enough onto the axle

. You can easily check this by removing the clickbox. Underneath,

you'll see the nut and the axle. The axle must

protrude at least 8 mm and no more than 12.5 mm from the nut for the clickbox to be mounted correctly. If the distance is incorrect,

there is either too much or too little space on the axle to properly attach the clickbox.

This can lead to shifting problems later on. This is often due to too many components behind the nut,

such as rack struts, mudguards, or washers, or simply to

the axle being the wrong length. If this is the case, you either need to remove the components behind the nut

or install a hub with a different axle length. If this distance is

correct, then you need to pay attention to a few things when mounting the clickbox. For proper installation,

first, this clamping screw on the side must be unscrewed until

it is no longer visible from the inside, so that nothing

can obstruct the assembly. Unscrew it from the outside to approximately this extent. The clickbox has internal teeth

that allow it to fit onto the nut on the axle. When attaching the clickbox,

you must therefore simultaneously turn and push so that the teeth of the clickbox can slide correctly onto the

nut. Once the clickbox is in place, you should

hold it pressed against the axle with your thumb, otherwise the clickbox will be pushed off in some gears

. The small viewing window here allows you to quickly check if everything is seated correctly.

If, as shown here, you can just see the end of the axle through the window,

then the clickbox is seated correctly and far enough onto the axle. For comparison, here's

how far it's not seated on the axle, and here's how far it's seated. If everything checks out,

hold the clickbox in position and simultaneously tighten the clamping screw on the side

securely with a 10mm open-end wrench. The clickbox should then no longer be

able to be pulled off by hand and should remain firmly attached to the axle after shifting. If

shifting problems persist, the shift pin might

be the culprit. If the shift pin is crooked or bent, for example, it won't move

smoothly and can get stuck in the hub, causing the derailleur

to get stuck in a gear and not shift further. It's also possible that the shift pin

is simply the wrong length. The Nexus 3-speed hub gear comes in three different lengths

, depending on the axle length. If the wrong shift pin

is installed, some gears can no longer be engaged, and

shifting errors will occur in general. You can easily check if the shift pin is the correct length by

carefully pushing it into the hub until you feel the first resistance and then measuring the protrusion.

The shift pin is the correct length if it protrudes 14 mm from the axle in this position.

I've

explained everything else about how to find the correct shift pin in more detail in the second short video in the video description. To check if the problems

originate from inside the hub, i.e., from the internal gear unit, you can

perform a pressure test with a shift pin. Push the shift pin into the hub; you should

feel resistance. When you release it, the shift pin should spring back out immediately.

However, if the shift pin cannot be pushed in or doesn't spring back out,

even though it's straight and the correct length, then it indicates that something inside

the hub isn't working properly. Most of the time, the problem is either grease that

has dried out or hardened and become sticky inside the hub, or the internal mechanism is damaged

and something is blocking it. With outdated grease lubrication, sometimes

an immersion bath of the internal gear unit in a special maintenance oil can help. In case of doubt,

however, the entire internal gear unit of the hub must either be replaced, or it

must be removed, disassembled, completely relubricated, and reinstalled.

I have

linked videos on oil bath maintenance and on the complete overhaul and relubrication of the Nexus 3-speed hub gear as the third and fourth videos in the description. Another tricky spring lies inside the click box.

The end of the shift cable behind the clamp should not protrude more than 4 mm. If the

shift cable protrudes too far, it will hit the plastic cover at the rear when shifting.

This prevents the first gear from being engaged. Therefore, the end of the shift cable should

protrude a maximum of 4 mm behind the clamping screw to ensure smooth shifting of all gears.

Of course, it's also possible that the shift cable and housing

are damaged or worn. This disrupts the transmission from the shifter to the derailleur on the rear wheel. The shift cable

and housing are wear parts that wear out over time and eventually

need to be replaced. Issues such as a frayed or kinked

cable, damaged housing, internal rust, kinks and pinches, or

an excessively tight bend can prevent the cable from

sliding smoothly within its housing or cause it to jam. The selected gears will then only shift after a few seconds or

not at all, because the transmission is either sluggish or blocked. In this case,

the shift cable and housing must be replaced. Detailed instructions

, including everything you need to know, can be found in the fifth video in the video description. The

most common cause, however, is that the shift cable is clamped in the clickbox with completely the wrong distance

. This isn't just the section behind the clamp, but the entire shift cable is

clamped incorrectly, or it's clamped too loosely and is simply

pulled out of the clamp when shifting. A typical sign of this is that when adjusting in second

gear, the yellow line won't move between the two white lines at all, even though the adjustment screw

is either fully screwed in or completely unscrewed.

To fix this, you need to readjust the clickbox, meaning

you need to clamp the shift cable correctly in the clickbox. In short, in third gear, you need to

position the shift cable between the clamping plates, push the lever all the way forward, and pull the shift cable completely

out. Hold it in place, tighten the clamping nut securely, and then

trim the end of the cable to 4 mm. I've explained the entire basic adjustment of the clickbox

in more detail in this video. Feel free to write in the comments what your problem

was, and if the video helped you, I would also appreciate a like and a subscription.