ign1te

Nexus 7 straight out of the hub shell. Nothing has been done to it besides removing it out of the shell. And no, "dirty grease" is not the answer.

altenwrencher

The grease obscures it some, but on the largest piece I see a chunk of metal missing near its left edge, facing the camera.

ign1te

there is more!!!

altenwrencher

Could be. Without wearing nitrile exam gloves, I don't detect anything else.

Troul 

if you're hungry, go make a sandwich... don't be chomping on hub parts!

ign1te

Dan Burkhart

grumpus

Bits of extraneous metal jammed in the freewheel? Guessing, I've never had much to do with these, I used to be good with Sturmey Archer.

CrimsonEclipse

You used an internal hub?
(what do I win?)

Reynolds 

Maybe it's the angle, but parts look misaligned.

dedhed

Never had one of these open but What's going on here.

ign1te

I will announce the answer in a couple of days in no one finds it.

Duragrouch

At midpoint there appears to be a dog-clutch, thin metal cylindrical part with axial tabs, that appears to perhaps be missing a section between tabs. Hard to see with all the grease.

Just to the right of that, looks like a ring of some sort with a good chunk of it missing.

Also the cylindrical section to the left of the right caged bearing, someone had mentioned a chunk lower in the picture, but the same part high in the picture also looks chewed. Inside of that, the planet gears look not fully engaged, partly slid out axially.

ign1te

Last sentence is getting close. Be more specific about why this has occured.

Duragrouch

Something getting shorter... something getting longer... something getting unclipped...

Not having a clue how that hub is constructed, I'm gonna take a first stab at it and say that the (pic) left end wheel bearing disintegrated or the cone loosened, and that's what holds the whole assembly together axially, or simply a locknut on the axle that does the same and rotates with the whole assembly.

Wow, I'm seeing more and more damage, huge chunks taken out of carriers or plates.

Shadco 

It didn’t work as a rock crusher.

.

ign1te

Retaining ring that keeps the rods in their place has failed. Rods are protruding past their normal position (picture). This caused gear mis-alignment which led to further damage.

Duragrouch

Is the retaining ring a big wire ring, or a flat plate like a giant c-clip? Is it fixed or free to rotate with respect to the pins? I'm just wondering about why it failed, if under any stress, or just fixed with respect to the pins and there was fretting wear at each contact point?

veganbikes

Exactly what is the flaw in using an internally geared hub? Is it because you don't understand their utility or because they did something to you or what? Yes there are drawbacks to an IGH system just like there are drawbacks to using a derailleur and drawbacks to a fixed gear or single speed application. However in many cases the IGH can be quite superior if done right for a wide variety of riders. It won't be ideal for someone racing or who needs really quick gear changes but that is a small number of the cycling population. Also consider that Sturmey-Archer is still producing their hubs with not a ton of change for way longer than any derailleur has been around is pretty decent testament to their staying power. Granted yes S-A did get bought out by SunRace but I can still get a shifter that can work with an old 3 speed hub from the 50s is pretty neat. Now I am not saying I am a S-A fan just pointing out the longevity of their product compared to say a Dura-Ace derailleur which will change every 3-6 years or so and not always be backwards compatible.

ign1te

Looks like this.

https://www.sjscycles.co.uk/hub-spar...-1110/?geoc=SE

Came out of its groove. Could be error during assembly or material failure. These rings are not under load.

Duragrouch

Yep, that is definitely of the Big Wire Ring type. Usually when in place, the spring is under light tension, or if higher, insufficient to cause metal fatigue (and it's put in place by slipping over the end, so don't need to open wide over the diameter), or none at all after being in the ring groove. However, the hook on one end indicates it remains fixed in rotation with repect to the carrier, and thus *possibly* fixed with respect to the planet gear pins, thus, I am gonna guess fretting wear at those points, which you may find evidence of (flats), unless after failing, the part got so chewed in the mechanism to not allow a post-mortem failure analysis. If the spring is not fixed with respect to the pins, then sliding wear from the pin ends may be the answer, and thus very smooth and rounded pin ends, as well as good hardness on the spring, may both be critical.

GamblerGORD53

Soooo, somebody rode that until the dirt screwed up the shifting and that broke stuff.... and now you wonder why?? LOL

ign1te

I think you misunderstood the whole point of the thread. I suggest you grab your walker and head back to bed.

tiger1964 

So, the ancient Sumerian Wankel rotary engine, brought to earth by ancient aliens? That's all over the internet...

Duragrouch

Now don't be opening up a whole mess'o'potamia. Who knows what will eNSUe.