Electronics, Lighting, & Gadgets - "Shimming" speedo sensor to fit bike?

I just got my Blackburn Delphi 6.0 last night. Installed it this morning on my Trek 7.3 FX.

The wireless speedometer doesn't work. The battery is good. I think the sensor on the fork and the magnet on the spoke are too far apart. The manual says they should be 1 to 3 mm apart, but there is no way I can get them that close due to the wide fork.

The cadence sensor is working (didn't check accuracy) even though it is also supposed to be 1 - 3 mm away but is at least a cm away, also due to bike geometry.

Anybody had a similar problem? How'd you solve it? I'm going to have to get some extra zip ties and try to find ways to shim the sensor out toward the spoke magnet.

I'm unfamiliar with your bike and fork, but I found that my Delphi 4.0 is extremely sensitive to sensor/magnet positioning. Not only distance, but also where the magnet passes along the sensor.

When I first got it I was frustrated that the thing worked just fine if I held the bike up and spun the wheel, but as soon as I got on the bike, it stopped working. All I can figure is the miniscule amount of spoke deflection caused that problem.

I also found the cadence sensor to be much more forgiving of magnet placement. It seems like all it needs to be is in the same county and the cadence sensor works.

Anyway, I now use a CatEye wheel magnet which is both larger and more powerful, and have it positioned so it spins right between the zip ties and nearly touches the sensor as it spins by.

Also, mine came with a nearly dead battery in the wheel sensor. Try a fresh one even though yours is new.

It's working now (at least spinning the wheel.) I twisted the transmitter toward the inside of the fork until it came near enough to the magnet.

(When I wrote the above post from work I was remembering it as not being close enough to do this.)

if it is a zip-tie connection to the fork, just put some plastic, metal, wood, or cloth between the sensor and the fork until it is close enough. i'd maybe try some old credit cards chopped up