I was looking at the Shimano Nexus 8 speed hub on my Cannondale Adventure and it occured to me that I don't know how to get the wheel off "enough" to change a tire. Do I just swing the wheel around and leave everything intact working on the wheel beside the bike? Do I disassemble something where the cable meets the hub? I am perfectly capable of taking the small inconvenience of a flat and making a disaster of it.

Most, or almost all people disconnect the gear wire so they can drop the wheel and work on it untethered. That means that besides knowing how to fix a flt, you need to know how to install the wheel using the anti-rotation washers, and how to adjust the gear control cable.

It's really easy, and if you have a relationship with a shop, they can teach you in a few minutes (bring them a beer or pizza). Otherwise search for nexus setup tutorials.

This is something you need to know. On my evening commute, I routinely meet riders who've flatted a rear, and have changed the tube, but are stranded anyway, because they can't get the wheel back on (both IGH and derailleur bikes).


There is an alternate technique that I've used in emergencies, which is to leave the wheel in place, pull out one side of the tire, slap a quick patch on, and remount the tire. You can't replace a tube this way, but if you know where the leak is you can save enough time to catch a train you'd otherwise have missed.

Once you do it, you'll find it is really easy.
Does yours have a roller brake? That adds a step.

Here's one video: This one shows an Alfine with disc, but the gear change cable process is identical.
A couple of comments on how this guy does it - first, you don't need the pliers to get the cable stop out of the hub mechanism. Instead, once you've used your spoke or 2mm hex key to rotate the shift mechanism, simply pull the cable housing out of the armature and the bend int he cable can be used to rotate the cable stop so it comes out easily. It is far easier demonstrated than described.

Have a knowledgeable person at your LBS show you - it would be very beneficial.


Once you get the hang of it, you can have the wheel off the bike in a matter of seconds, add 10-15 seconds if you have a roller brake.

The video is pretty good but there is one error. You don't need to set the gear to 4, just to the slackest setting (gear 1)
The nut (that is fixed to the cable) slots into the cassette arm. You relieve tension on the arm (using a small allen key), grab the nut with pliers. Note that the nut has some flat sides which you have to align with the slot int he cassette arm, you need to apply a very small rotation to line up the flats then the bolt and cable come off.
Do NOT remove or adjust the nut and bolt on the cable, this is set precisely.
There is no need to adjust cable tension on re-fitting. If you do need to adjust the tension, this is where you need the gears set to 4 so you can align the yellow marks using the barrel adjuster.

Make a note of the colour of the anti-rotation washers on each side, they set the hub axle at the correct angle for your frame. You shouldn't need to remove the wheels nuts completely but if you do, you need to refit the correct colour of washer.

Tools:
-wheel nut wrench. I prefer a small box wrench that encloses the bolt, rather than an open crescent wrench. Vertical dropouts don't need as much tightening so can use a shorter wrench. Horizontal slots need more wellie so a longer wrench.
-Pliers. Small, needle-nosed such as on Leatherman tools. Electricians pliers are small and light.
-Tiny allen key or small nail to fit onto hole in cassette arm. You can work the cassette arm by hand but it gets dirty.

That guy makes it complicated. I just grab the housing just before it goes in the holder at the hub, pull it out (set it to first gear beforehand), and maneuver it out of the slot. Then I just pull the cable around such that the gear change pulley swivels around at it pops out the slot (there is a plastic sector on the pulley that acts as a keeper, you have to watch for that). To re-install, I snap the cable anchor back into the slot and then carefully route the cable around the pulley, pull the housing back around, guide the cable back thru the slot in the holder and reset the housing back in the holder. No tools at all needed, aside for a wrench for the axle nuts.

The technique shown in the video is fine for the workstand in the shop, but in the field, I just use my quick and easy technique.