New Garmin Speed & Cadence Sensors

Updated 12 April 2015

I thought I'd treat myself and have a small (but relatively expensive upgrade). As a plug I ordered from Wiggle (with some other items) with free delivery and received within 2 days so excellent service as normal from Wiggle. But no Haribo this time.

I have bought the new Garmin accelerometer based speed and cadence sensors. This came in what seems to be the standard Garmin box:
 

Here's the official "sales photograph of the 2 sensors:


The proper part number is: 010-12104-00 (Link)

This purchase was partially to replace the GSC10 on my Scott but also because the GSC10 on my Giant appears to have failed. Therefore I would fit the new parts to the Scott and move the GSC10 from the Scott to the Giant.

Here's a GSC10:

Here's a GSC10 with the wheel magnet

I initially paired the units off the bike. I had read some articles on "that there internet" saying that people had had trouble pairing the new units and could only get one or the other. The issues seems to relate to the GSC10 being described as "Spd/Cad" sensor and the new unit being described as "Speed and Cadence" sensor:

Speed and Cadence Sensor Screen on Garmin 800

(yes I know that the 800 can take a screen shot but it was quicker to just use my phone). I started by disabling the GSC10 sensor from the bike profile. I then tried to re-pair which failed (normal behaviour I believe). I could then try again and then select "Sensor Type", and here I was able to select "Speed and Cadence".

It beeped at me a few times suggesting that it had found the 2 sensors. I then shook them about to simulate rotation and was able to get a reading of both speed and cadence. I noticed that whilst the speed sensor seemed to repsond quite quickly (what might be equivalent to a few wheel rpm) the cadence sensor seemed to take a lot longer to start to display a value - long enough that I thought that it had not paired and I repeated the process several times

It would appear that others have had this behaviour as well - and when I fitted it to the bike I got the same delayed start of monitoring.

Having established connectivity I fitted the sensors to the bike (phone photos so not great quality):

Wheel Speed Sensor

Wheel Speed Sensor

Cadence Sensor

Cadence Sensor

It is certainly easier to fit these sensors compared to a GSC10 where you need to try and fix it to different shape chainstays, then fit the magnets to a spoke and the crank arm and then try to jiggle the position that's optimal for both magnets without hitting any of the rotating parts.

Visually I think the cadence sensor is better, and whilst the chain stay is now clean, the wheel speed sensor does look quite bulky

Trying them both with the Garmin on the bike repeated the detection of the units - speed sensor quite quickly responds whilst cadence needs a number of turns. Whether in the latter case this is related to the unit going to sleep to conserve the battery and hence needing a wake process I don't know.

I've not ridden on the road yet so time will tell how they perform.

Updated 12 April 2015.
Firstly I had a very difficult time getting the new sensors to stay connected if I had powered the Garmin off or the sensors themselves had powered down. Lots of pairing and re-pairing followed and in the end I had to resort to looking on the internet. The solution appeared to be to remove the batteries, wait and then re-insert them. This apparently takes them out of "shipping mode" - whatever that is. After having done this I don't seem to have had any further issues with the sensors waking and pairing correctly. The wheel speed sensor is ready before I set off as it has already woken as the bike is moved, and the cadence sensor seems to wake after about 4-5 pedal strokes - generally once I am actually riding. I am glad I have resolved this as I was about 5 minutes from sending them back! Quite why Garmin could not have documented this in the instructions I am not clear and it would have saved a lot of aggravation and customer dis-satisfaction.