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Chiming in to say my Alfine 8 Speed (SG-7001-8 Disc) is still going strong after 10.000+ km's. It's on a touring/city bike that originally came with a Nexus 8-speed from 2017, but that one would sometimes slip half a pedal turn. I was never able to pinpoint the cause and the third time I opened it up I went to far with disassembly and un-seated the return-gear spring. This is kinda impossible to put back without specific knowledge/tools, so I ended up deciding to install the Alfine 8 speed and keep the Nexus 8 for spare parts. The Alfine has been in this same bike since and working great.

After 1000km I decided to remove all the Shimano grease and add Dexron VI ATF (automatic transmission fluid). Amount about 15ml, so there's always a little pool inside the hub. Switching gears became even quicker, but the hub also became a tiny bit noisier. My guess is the ATF was a bit on the thin side. After another 1000km I switched to Gearbox Oil Type: MPM Gearbox Oil Semi Synthetic API GL4/5 75W90. Amount also 15ml. This made the hub even quieter and gear change is still lightning quick. I think this is the better choice.

Note: From what I've read elsewhere: Avoid gearbox oil with a single GL5 type indication since that has supposedly additives that might react with certain metal parts. Another source argued however it only causes slight discoloration and only with high temperatures. Anyway, the mentioned oil should be safe for metal and for plastic as its been in my hub for 8.000km and counting.

Last week I opened the hub for inspection and everything looked absolutely pristine. Planetary gears, roller clutches, plastic ball bearing holders, the inside of the shell.. all looked like new. I even did a side by side comparison with some of the old Nexus 8 parts (with had less then 1000km) and I could not see or feel any difference! Picture shows left Alfine internal and right Nexus.

p.s
These parts are interchangeable, tried it.

The one thing to double check when re-assembling these hubs is to NOT over-tighten the nut that holds/clamps the internals into the hub shell. If you do, it will have a lot of drag because of extra pressure on the ball bearings and your back wheel will maybe only spin for a rotation or 2 when you give it a swing with your hand. Getting it just right is not hard though. Tighten the nut with your hand only and feel there's no wiggle/play in the axle. If done correctly your wheel will still free-spin at least 15 rotations.

I also put some ball bearing grease on the ball bearings left and right to stop any oil from leaking out. Also added some grease tot he big round plastic screw-on cap for anti-leak. And as others have mentioned: Gear shift cable calibration is critical. Get the marks aligned in 4th gear and re-check once in a while.

Although I don't climb up big mountains or do wild off-road MTB, I do stand on the pedals and even pull my steering for extra force when the green light shows and I generally go 30km/h and up. But with the proper attention I think this hub will do another 10.000km easily.

 

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This is one thread I'm glad to see getting resurrected from time to time. Good to see how these hubs hold up. My original hub is not in service, but not because of any problems with the hub. That bike died a literal, fiery death. The hub never stood a chance, but it worked flawlessly for the 6 or 7 months I had it. Built up a 2nd wheel at the end of 2015. After 3.5 years with that as part of my main wheelset on my main bike (probably around 10K miles), I finally decided I better do the "annual" service. I can't remember if there was an issue with the hub that made me think it was time. Possibly there was, or possibly I messed up reassembling the hub after giving a dunk in the Shimano hub fluid and lubricating it with the Shimano bearing grease, but around a month after finally servicing it, it froze up. I tried figuring out what was frozen and if it was fixable, but I had so many pieces out, wasn't sure I could remember how to put them back properly, and still hadn't unfrozen whatever had gotten stuck, so I gave up. I picked up a replacement on eBay, pulled the guts out, and replaced the guts of my hub. That was last September, and it's been running fine since then. Probably another 3000 miles at least.

Meanwhile, towards the end of 2016 I built up a secondary wheelset with the same model hub. Those wheels get used often enough, but not as much as my other set. I serviced them last summer as well. That hub has been trouble-free for going on 4 years, and I really don't know how many thousand miles.

Also, kind of related, got a bike with Nexus 8 in the summer of 2016. It's my back-up bike, so it doesn't get a lot of miles, but it's also a folding bike, so it's the preferred bike if I'm traveling but not touring, so it does get some miles in. It also hasn't given me any trouble, but I do want to swap it for an Alfine because it's always an adjustment with the "backward" shifting.

So, so far, 5 years on 3 different Alfine 8 hubs. Only one failure, that may have been my own fault, and along the way I've commuted 5 days a week on them, run errands and goofed around on the weekends on them, toured on them, etc. I rarely drive, so the bikes are my primary means of transportation. I'm still very happy with the hub, and the fact that I was able to swap the internals of my broken hub without even needing to rebuild the wheel is also a plus. I probably need to do another servicing some time this summer, but I have no qualms about using this hub for just about anything. Also, while I wouldn't mind a larger gear range, I've been pretty happy with that aspect, too. I think I have them geared close to the ratio that gives me the lowest gear within the recommended specs, and that's low enough to get me up most of the hills I have to deal with, and high enough that by the time in top gear, I'm happy with my speed. I'm not a fast rider, though, and don't mind coasting on the downhills, so I can see where someone looking to push themselves might want more range. It's been working great for me, though.
 

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Short update: Now at 12.500km, still on gearbox oil. No problems whatsoever. Very quiet and very quick shifting.

From all the years now with this hub and disassembling it multiple times I did learn that:

A) It's important to tighten the 2 axle nuts very securely. If you don't, the Alfine might rotate back and forth a tiny bit while pedaling. This will mess up the shifting alignment. The axle nuts are made of a softer metal compared to the axle itself, so don't worry too much about ruining the Alfine axle by overtightening the nuts. I used thread lock generously to make sure everything is as secure as possible.

B)
The nut that is holding the Alfine internals together should only be hand-tightened. Anything more that that will cause a lot of drag because of too much push force on the ball bearings. If your wheel isn't free-spinning smoothly (and it's not the brakes) it's probably this.

This hub is still a great value to me, but I do think the way it's mounted is a bit 'under designed'. The amount of rotating force on the axle can be very high. A torque arm (like on a Rohloff) to mitigate this force would be the prettier option instead of those anti rotation washers that always seem to have a tiny bit of play.
 
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