Powertap Issues

I want to update everyone on this situation. I decided to open the hub and see if anything was broken. I pulled the patent for the powertap off the online US patent database (Patent #6,418,797) and used the included exploded views as a diagram. I am happy to report a major breakthrough. The wire connecting the torque tube to the circuit board had been cut somehow, and rust was found on the powerclips on the chip. This indicates that WATER HAD FOUND ITS WAY IN! Not only did it find a way in, it couldn't find a way out, and eventually penetrated the silicone layer around the circuit board. Further, because the wires connecting the torque tube to the board are so thin, splashing water probably broke the wire.

After my repair, which included removing rust from components, and replacing wires that connect the torque tube and circuit board, I got a reading of 311 to go to 420. Though not perfect yet, I'll be working further on this issue and hope to fully correct it. If anyone has ideas or other suggestions, I'm open to them. I'll be posting photos of this repair along with a video on youtube on the steps taken.

Dylan

Early wired PT hubs had two major problems, one easily fixable and one not easily fixable. The easily fixable problem was that the wired pickup could pick up frame vibrations and cause data dropouts. The solution was to attach the wired pickup to the chainstay with a "soft" attachment method such as slinging the pickup loosely below the chainstay. The second problem is the one you discovered, that the early hubs were not water-tight. They worked for months on the waterproofing problem and eventually addressed it with both a tighter screw-cap and O-ring and with a material seal around the electronics (they sort of mummified the electronics). You might want to look into how they created the electronics seal because you may be able to duplicate that. I can't remember the material they used, but I think it is a commonly available material.

Here are some photos of the innards while I had the whole speal apart: (The upper part is the circuit board and the electromagnet that sends information to the receiver just outside the hub. The bottom is the torque tube itself, showing the thin wires and deformation sensors)
[IMG]cyclingforums.com700Open ↗[/IMG]

[IMG]cyclingforums.com700Open ↗[/IMG]

Hi just read your posts, I'm faced with the same problem with an early powertap hub. Can I ask did you post the YouTube video? Any more info would be appreciated. Regards Alan

Me too. I appear to have a water damaged hub. Would love to try and fix it Paul