For some reason the past month I’ve been dealing with wheels a lot. I’ve been building a lot of custom wheels and repairing a lot of wheel systems. It’s made what I like and dislike very clear in my mind.
Shimano isn’t the only wheelmaker to use this “innovation”: placing the nipples at the hub rather than the rim. Shimano is the most poplar one out there, though. The usual excuse for this is that removing the nipples from the rim reduces rotational inertia of the wheel. What it really does is make truing the wheel a bitch. It’s difficult to get the wrench (which is usually proprietary) into the nest of spokes, and then the arc of the wrenching motion is limited by the same cluster of spokes. And for non-radial lacing, the actual truing of the wheel seems unnatural because the problem area of the rim is offset from the nipple that would have an effect.
The one thing going for this design is at least I don’t need to remove the tire and rim strip to true the wheel, unlike the plethora of pseudo-aero wheels with nipples hidden in the rim.
The fact that Shimano moved away from this design can at least partially be due to professional cycling teams’ overwhelming preference for external nipples at the rim. I’m sure team mechanics hated those wheels with a passion.
As a sidenote, I should acknowledge that there are some hubs out there (some Hed hubs for instance) that have nipples at both ends of the spoke, such that the nipple at the hub is merely an anchor, while tensioning is accomplished with the nipple at the rim. Since you don’t true the nipples in the hub, I got no problem with this design.