In 2012 I bought this XL-RD5w hub from SJS, my first IGH. My spokes were slow coming, so I played with the shift chain several times. I kept wondering why it kept sticking going back in. I used it a year and liked it very much but, it didn't get any better. So the next annual take apart, I sanded the corners on the 2 key nubs. It was a little better, but still troublesome. The last time I tried it gears 2, 3, 4 wouldn't work at all, so I let it sit 3 years.
This week it was raining so I got it out again. I stripped it down to the axle and pinion planets assembly. I put it in the vice horizontally and spent an hour yanking on the key chain till I figured it out. There are 6 rows of 4 nubs in the assembly, so there are 5 slots the key goes in/ out.
ONE of them was OK, the other 4 were NOT. This may be why so many of these hubs failed.
=====The SOLUTION turned out to be very EASY. I got out my diamond bit engraver to mark the bad slots. Then I got the bright idea to use it to lightly grind off the last 6 mm at the mouth end of the slots and round off the lip more. The grinder works very fast, so it just takes 30 seconds each. I did this until the key had NO stickiness. I doubt it could be done without this engraver actually.
Then I spent all day converting the Rohloff setup and my chain case. Darn I can't find any old tour bike with 100/ 130+ dropouts. I took it out twice for 30 miles. It works PERFECTLY now. Yayyyy. So now it works as well or better than my 46/ 16T Rohloff, if only using gears 6, 8, 10, 12 and 14. LOL. SA is with 46/ 17T now so I can go try going 46 mph down my fave hill again soon. ha. This 5w is WAY faster than my new 3 speed.
SHAME SHAME on SA for putting me and likely many others thru this horrible ORDEAL.
.....But OTOH, I would have struggled with 35 to 92 GI in Vietnam with the SA 5w. LOL
== BTW SJS, did your mechanics ever figure out this FLAW?
And anyway, would a SA disc line up close to a Rohloff disc?