Latest TUNE hub generation is quite easy to service. Only the final step of removing the bearings is a bit difficult.
You’ll find here a step by step article about a Mag 190 rear hub disassembly. A front Mig 70 hub disassembly is almost the same, it only has an axle cap nut with two identical bearings.
– two 5mm hex keys
– a W-Mag disassembly toolkit.
– a cassette lockring
First, one has to unscrew the free wheel side cap nut, by inserting two 5mm hex keys in the axle ends. A thin seal or a small steel spacer are placed behind this nut.
The next step is to remove the rotor, you have two options for this;
- Pull (strongly) the rotor to the right side (viewed from riding position). Be cautious because it may be dangerous especially for campa rotors that has deep teeth. Morever you may damage the axle if you don’t pull perfectly in its axis. I don’t really recommend this method though.
- Use the small tool included in the W-Mag tool set (W1). You also need a cassette lockring for it. The small tool has to be completely screwed down then it has to be placed against the axle. The cassette lockring is then screwed on the rotor. While turning clockwise the tool’s screw, you’ll extract the body. It’s the crankset extractor principle.
A second steel spacer is placed between the rotor and the double bearing.
Only the axle and the bearings left on the hub body now. To extract the axle, you’ve two solutions:
- Place the drive-side of the axle on the ground and push the axle out of the body.
- Tap out the axle with a hammer via a wood piece or the tools of the kit (W4 or W5). The wheel has to be placed some centimeters over the ground. The best is to put the left side of the hub on the big part of the kit (W3).
(I’ll plug in a better picture as soon as I get back my camera.)
The bearings are tapped in while using the W6, while extracting the axle a bearing may remain stuck on it:
I could find only some solutions to solve it:
- Put some loctite glue on the bearing. Place back the axle in the body and wait some seconds to make the bearing and the body standing together. Then try again the axle extraction procedure
- Heat the axle then place a thin thing between the bearing and the end nut at differents places to force it to move.
You still have to pull out the bearings. It’s tricky since it usually damage them. One has to tap on the inner race of the bearing to force it to leave its bed. A good idea is to heat the parts around 60°C to make the disassemble easier. The classic bearing and the tune patented one are still working well, I won’t go further in this article. These bearings will be replaced by ceramic ones in a few weeks.
The W-Mag tool kit: