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flattie 07-18-11 06:50 AM

Garmin GSC10 cadence magnet
The cadence magnet for the GSC10 sensor that attaches to the crank on my bike has disappeared. It's the one that comes in a little oblong black plastic holder with a slot for the zip tie. I guess the zip tie wasn't snugged down enough and trying to clip in from a stop light I think I knocked it off.

Anyway - does anyone know if you "must" use that specific magnet or can I use any old magnet in its place?

I can get a 10 pack of 3/8th's sized rare earth magnets off amazon for less than what they want for a single set of replacement magnets from garmin


PS - Last thought - since a full GSC10 kit runs about $35 am I better off getting that to have a spare? Seems excessive - particularly since I don't ride in the rain unless I get caught out.

Shimagnolo 07-18-11 07:00 AM

Buy 1/2" magnets, then stick them to the back of your pedal spindle.
Stack them high enough to get close enough to trigger the GSC10.
Note that of course you need a steel spindle for this to work.
I do this on all 4 of my bikes.
No more ugly zip ties and plastic bits.

I use these:

When removing the magnet stack, you will need to hold a large chuck of steel against the bottom magnet on to pull it off of the spindle. The side of a large crescent wrench works well.

sojourn 07-18-11 07:02 AM

Go with the rare earth magnets. I switched over to the rare earth magnets many moons ago and they work great...look better too IMHO.
Ride safe-

flattie 07-18-11 07:16 AM

Thanks for the quick responses. I'm pretty sure my cranks are aluminum. They are the FSA Vero Forged. So if I go with the rare earth magnets do you think double sided tape, hot glue or epoxy adhesive would work okay?

Edit: I need to read more carefully - Shimagnolo suggested attaching them to the back of the pedal spindle. Those I believe are steel - I'll need to go home and see if that's a viable mounting location. I'm somewhat restricted as to where the GSC10 is mounted since I have disc brakes and the brake cable runs along the chainstay not to mention the avid bb5's are mounted there. Presently the GSC10 is mounted "upside down" or it's hanging from the underside of the chainstay. Not sure how far rearward I can move it.

Shimagnolo 07-18-11 07:17 AM

Not the crank, the *spindles*.
They are likely steel unless you spent the big bucks for Ti.

flattie 07-18-11 07:39 AM


Originally Posted by Shimagnolo (Post 12944681)
Not the crank, the *spindles*.
They are likely steel unless you spent the big bucks for Ti.

Yeah I edited my response - guilty as charged for not reading your original reply carefully enough. What you suggest is what I am going to try tonight when I get home. I have shimano m540 spd pedals which do have steel spindles. Thanks very much.

mike723 07-19-11 02:17 AM

go to look under garmin. A replacement magnet set is $9.99

chasmm 07-19-11 10:09 AM

Here's a link to my post on the Garmin forums where I did this and posted some pics of it...Using a rare-earth (neodymium) magnet to replace the GSC-10 crank-arm magnet

I done this on all my bikes and haven't had an issue yet. As I mention in my post, I would try to get the magnets that have a hole in the center...they're much easier to remove...

Good luck

Looigi 07-19-11 02:37 PM

Yep. Like others I use a 3x12mm rare earth magnet stuck to the inside end of the pedal spindle. Works well on three different bikes. It'll trigger the sensor from well over 2 cm away. I find them easy to slide off when needed.

BarracksSi 07-23-11 09:25 AM

I don't think I'll own enough bikes to use up the package of rare earth magnets I got from the hardware store, so when I sold my CAAD8, I just left the magnet glued on the crank.

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