A simple guide to adjusting a Shimano Nexus hub gear

I thought I’d impart a little bit of advice on an aspect of bike maintenance that was slightly foreign to me, and hopefully that I can explain with the aid of pictures. If you are an expert bike mechanic, then this probably isn’t the post for you, as I expect you know all this already. If not, then I hope it is of some use, if you have a gear set-up similar to mine.

The joy of a solidly built Dutch bike is that it is almost entirely maintenance-free, so these kinds of maintenance issues are something that you don’t really have to deal with. To put this into perspective, I’ve had my Workcycles Omafiets for about nine months now, and cycled with it in some pretty awful weather.

DSCN9832But apart from mending one puncture (a hawthorn spike went straight through my rear tyre), pumping up the tyres every month or so, and wiping down the frame and wheels with a cloth, what I am about to describe is the only bit of ‘servicing’ I’ve had to do. No chain cleaning, no brake maintenance – nothing else. (By contrast, my previous bike did require a fair amount of regular cleaning and maintenance of the transmission in particular, because it was exposed to the elements.)

After a few months of riding, I started to experience some small issues with my gears. Nothing too serious – just that they wouldn’t engage in the gear I wanted, or would jump from one to another. The problem results from the gear cable stretching with use, meaning that it is no longer pulling the parts of the hub gear into the proper position for smooth gear changes.

Anyway, here’s what you need to do to address this problem if you have a similar Shimano Nexus hub. The first thing to do is to set your gear adjuster in number 4 – it is marked with a small dot on the display, for clarity (mine is an eight speed, with a coaster brake – but the same principle applies for other Shimano hub gears; select the ‘marked’ gear).

DSCN9670 Next, you need to remove the chain case. Mine has a simple detachable rear section, that pulls off smoothly. Just squeeze in at the top to release -

DSCN9672

then move back to detach.

DSCN9673

This will expose the chain, and (for our purposes) the relevant part of the rear hub.

DSCN9676

You will be able to see, by looking down on it, two yellow markings, just outside the chain – visible in the picture above.

If you want to eliminate clunky and uncertain gear changes, the two yellow markings have to line up (they represent the ‘fixed’ part of the hub itself, and the rotating adjusting section, that actually shifts the gears inside the hub – but that’s not too important).

It’s very easy to do this – you just need to fiddle with the gear adjustment knurl back up on the handlebars. It lies on the cable coming out of the gear shifter.

DSCN9671Rotating the knurl will allow you to line up the yellow markings. I was going to go into a description of which way you need to rotate it, but on reflection it’s much easier if you just turn it a little bit and see which way the yellow marking has moved. If it’s got closer, keep rotating in that direction; if not, you need to rotate it the other way.

Once they’re lined up, you’re all set. All you need to do is replace the end of the chain case (slot it in at the bottom first, then click the top bit in) and you’re ready to go. Done!

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14 Responses to A simple guide to adjusting a Shimano Nexus hub gear

  1. Paul M says:

    We have bikes with the Nexus 7 hub, with a lever-operated rear roller brake. Process is basically identical, with 4th being the reference gear, except that the the two marks on the hub are red.

  2. alisonsye says:

    Sorry to go off subject here, but where is that church?

  3. Andrea says:

    It is best to do the adjustment with the cable released in first gear; then shift back to fourth to check. A little more fiddly but more precise.

    • alf-peter says:

      thanks andrea, trying your approach first and having other suggestions present in the back if the mind got settings right,

  4. Mark Small says:

    Wow, that’s very easy adjustment! I’m definitely switching to hub gears for my next bike, derailleur gears are so faffy.

  5. Prawsk says:

    I own a Batavus Lento – fantastic Dutch bike – however, adjusting the nexus brakes at the rear end are the easiest maintenance issue. It has hub brakes and if there is any operation involving removing the rear wheel, for instance replacing the tire, getting the wheel off by undoing brake and gear cables etc is nightmarish, and gets worse when they all have to be put together again. I’m a fairly competent bike mechanic, but find this difficult and frustrating. My tip? Get rid of the ineffective rear tyre that comes with the bike and replace it with either a Schawalbe or Continental which are less prone to punctures etc.

  6. S Pankhurst says:

    Just wanted to say thanks very much for taking the time to put these notes and photos up. Really useful and bike now fixed!

  7. jimjwright says:

    Thanks for writing this down so clearly, really useful!

  8. Tim says:

    If this doesn’t fix your problem, here is something else to look for if your nexus won’t downshift. When I tried to downshift my Nexus I found the cable casing would pop out of the adjustment knurl and no shifting would happen. No amount of adjustment would fix. After unattaching the cable from the hub, I realized the hub was not pulling on the cable the way it should. There is a spring inside the hub that wants to put it into 1st gear. Pulling on the cable with the shift lever works against that spring to pull it into higher gears. If the spring is not pulling, there is no way the cable can push it into lower gears, so it pushes out of the shifter instead.

    To see if this is your problem, find some instructions on how to remove the rear wheel (e.g., to fix a flat), the first step of which is to unattach the cable. To do this you put an allen wrench into a little hole, which allows you to push against the spring, removing tension on the cable. After the cable is unattached, use the allen wrench in the hole to move against the spring back and forth through the full range of motion. You should feel strong resistance through the full range. In my case, something was binding around 4th gear, and the mechanism would actually get stuck there. I took the wheel off thinking I would need to take it to repair shop, but then discovered the binding was no longer happening. There is a simple finger turnable lock ring that holds the cable “cassette” on the hub. This had become loose, which is what allowed the binding to happen. Tightening this into proper position fixed the problem. The last minute of this video shows how this lock ring works.

  9. Ian says:

    I was able to fix my gears in a snap! I adjusted the cable then checked to see if I was turning the adjustment screw the right way and as luck would have it, the markers were spot on.

  10. Jan says:

    Great article for hub newbies. I was there some time ago and can appreciate the worth of this.

  11. katherine says:

    Wonderful! I’ve had my Azor omafiets for just two weeks and the gears were slipping (mostly from 5th to 4th/6th). Your guide was the best I’d find for a novice to internal hubs like myself. Thank you, problem solved!

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