Garmin GSC 10 Speed Cadence Sensor for Edge and Forerunner Series (010-10644-00)

Does everything as advertised. With the bicycle function, it makes me happy I bought the 305 vs. the 405. I can only kick myself for buying an actual bike computer three months earlier.

The mounting process for the cadence sensor is fairly weak when you consider composite/carbon fiber chainstays and tapered tubes. The zip-ties aren't tight enough to keep the unit from sliding one way or the other and it eventually moves too far away from the magnets. Strong double-stick or industrial Velcro would be a better mount.

Cool tool to use if you can get it to synch properly. It is verrrry sensitive and if the adjustment is not perfect your cadence will not register. After several bike rides I find that I have had to readjust it each time. My ADD is starting to kick in and I am finding this to be a pain. It is entirely possible that due to operator error I may have not installed it properly at the beginning. Once hooked up properly it sychs seemlessly with the Garmin.

So if you have the patience( and good installation skills) go ahead and get it, the price makes it an easy purchase and this can be a beneficial tool in your training.

I purchased this product a few months ago. Installed it very easly. It took about 10 min for the installation. Works great. I wish I had this stuff when I was racing.

I am using this on my second bike - and it and the entire Garmin Edge 305 system, works very well.
The Edge 305 has multiple bike profiles, so I've tuned the second profile to this sensor.
Care needs to be taken to install the sensor correctly so it aligns properly with both speed and cadence magnets.
The only observation is that the cadence magnet, the one that sticks on the left crank, is a little tricky to space relative to the sensor. In one bike it required a home-made spacer, such that it would bring it closer (within spec) to the sensor. This will depend on your bike and as I said I only had to build this for one of my bikes. Still, it would be nice if Garmin offered such a spacer.