Garmin GSC10 - Installation and Accuracy

There's a family history and a bit of a yarn, as ever, associated with my history of Heart Rate Monitor (HRM) ownership, but this post is going to concentrate on the installation and use of the Garmin GSC10 Speed / Cadence Sensor on my bike.

I happen to own the Garmin FR60 sports-watch as a result of an entirely different need where I wanted to combine an HRM with a foot-pod for my jogging training - again, there's probably a reasonable blog, based on the decision making process I followed for that purchase, but the bike Speed / Cadence sensor wasn't actually a big part of it. Anyway, cutting to the chase, my fantastic family managed to slip the GSC10 into my Christmas stocking and I've been eager to give it a blast ever since.

It's a kind of strange looking device and if you ever try to get some web help for it, you'll probably find as I did that the way it gets attached to the bike frame isn't exactly obvious. Further to that, some of the product complaints about the design led me down the wrong path in installation.

Anyway, to make this blog entry as succinct as possible, check this out...

NOT how to fit the GSC10 to your bike

That's kind of how it comes out of the box, and web reviews of the product made mention of the slight wheel speed sensor and how the easiest of knocks might cause it to get entangled with the spokes... I was in a bit of a rush to get it installed and get out there, so I just thought - "yeah! that is a bit shit!". But there was a nagging doubt in my mind. "People who make products as good as Garmin, generally wouldn't out a product if it wasn't reliable, I've got something wrong..." The staggering inaccuracy of my first run was testament as to how wrong.



Compared to the Endomondo results using the GPS on my phone.


Double the disctance at twice the speed... you'd have to be happy with that... unless you knew it was total ballocks.

I've had to have a right good talking to myself about the 3 fundamental errors I've made here.

1. Rushed to the installation
2. Rushed the installation
3. Rushed away from the installation , without testing it... without even having a plan to test it!

The first big mistake - and it's an embarrassing one too! is that the bloody sensor arm shouldn't be pointing up in the air like some sort of phallic, tenement flat TV aeriel, it folds round the back of the frame to get protected by the frame from being bumped into the spokes... like...

Rotate the sensor arm around to protect it with bike frame

Doh!!! That's better!
On the accuracy thing, well I have 2 thoughts. One (less likely) is that the Speed sensor was also picking up the pedal magnet, thus giving more than one magnet pass per wheel revolution. The 2nd is that when I started turning the pedals and my watch said it had picked up the bike sensor without me needing to run the 'pair' operation - I assumed that it had picked up the right bike sensor and I didn't need to run the pair operation... you know what they say about 'Assume'... and there I am.. a great stonking ass!!

'Paired' them up just to be sure and went for a couple of short test rides along the road. FR60 now agrees with the Cateye Mity 8 - which is a perfectly good bike computer - that came with the bike. So, now I have my Heart rate, cadence and speed fully integrated... Workouts can be exported to Endomondo... but what I'm really looking for now is an ANT+ enabled phone, running Endomondo and talking to all my Garmin toys... that would be sweet... but for now, I'm a happy camper... Although I suppose I'd better get that chain oiled soon...


I still think the instructions suck though!