Originally Posted by
Unca_Sam
Fantastic! Here, I thought cartridge bearings were an upgrade. Apparently, only if well designed.
There are advantages in that you can replace both inner and outer races. In the old cup and screw-on cone bearings the cups were generally not replaceable. Then again, I have a pair of 40 year old campy hub wheels that you can't see any wear on the cups. Cup and cone angular contact bearings don't have seal friction. But they don't have seals either. So dirt can get in. Angular contact bearings (cup and cone) are better at handling side forces. Not sure that cartridge bearings are a slam dunk upgrade. They are more convenient.
Then again, the world seems to be trending towards convenience rather than quality. Look at CDs vs records. CDs have a limited bandwidth compared to records. So a good record with no scratches, played through truly high fidelity equipment, has better sound than CDs. Super Audio CDs (SACD) are better, but rare. Sigh. I'm a dinosaur.
Originally Posted by
Unca_Sam
IIRC, these hubs are adapted through-axle hubs. Poorly, it seems.
This is interesting. Yeah, if they were an adaptation of another design they could have been done better. The axle could have been 8mm longer. The bearing bores could have each been 4mm less deep (or 4mm spacers could have been used). This would have made the end plugs smaller, with less moment. This lower moment might have solved the problem completely. If not, the "labyrinth seals" (the disklike protrusions on the end plugs) could have been made with a diameter about 0.06mm smaller. This would mean that when force is applied, the disk would not touch the hub.
As long as I'm criticizing, there is a raised portion on the inner face of the inner disk. This keeps the plug away from the bearing face. The raised portion is not raised enough. If one has grease on the disk (which the hub had - presumably to avoid the screech) then you've added a lot of viscous drag between the disk and the bearing seals and outer race.
I'm going to pull the plugs again and remove most of the grease, with only a little bit left near where the red circles are in the sketch.
I'm surprised that DT didn't make the axle longer, the end plugs shorter, and the stand off raised section thicker. These are no-brainer improvements in design. But they may have had a bunch of extra hubs that they could pawn off on Trek/Bontrager. The hubs work ok except for the screech. But if you pay 1200 (originally) or 950 (now) for a wheelset, you kind of expect not to have any screeching!