Shimano NexusSG-7C21 Right Hand Dust Cap "C"

Pros

Shimano Nexus hubs have been used extensively worldwide for at least a decade, primarily by commuter and utility riders. I have owned and worked on four, two 7 and two 8 speeds. I was a prof bike mechanic from 1972-92, was an expert with Sturmey Archer 3 speeds. I have swapped out Nexus internals a few times prior to this purchase. I bought it because 4th gear on my five year old Nexus skipped, at times. I was excited about using it with the Microshift hb shifter, after frustration with the cheapness of Shimano's twist shifters, which did work all right but would come apart sometimes.

Cons

I carefully followed the Shimano instructions for installation and adjustment, had done this with several Nexus hubs previously. It worked as expected on the bike stand but one shift on the test ride - I believe from 4th th 5th - was evidently misaligned and some major pieces in the hub were evidently crushed, turning it into a piece of $133 junk. Traumatic, to say the least. I still have no idea what I did wrong, have re-installed by old internals with the Microshift and again, it works great on the bike stand. I'll wait a few weeks to try a test ride.

Other Thoughts

My wife's Nexus has been trouble-free on her city bike for years. She uses the standard clickshift (I hate them) gizmo, which also has a cable adjuster. The Microshift hb shifter comes with none, and I'd rigged one up in a clever way that might have been my downfall. My own experience with two Nexus hubs suggests to me that they are a bit fragile and require careful shifting, are nowhere near as robust or quick-shifting as Sturmey Archers, which don't strip out pieces if they're misadjusted. I have an SA "hybrid" gear train on one of my bikes and it's great. Maybe God is telling this old-timer to stick with that.