Garmin cadence sensor (magnet-less)

Bobbinogs

Chaps, I have bought one of the Garmin magnet-less cadence sensors and the blinking thing keeps falling into a slumber like a drunken man after a day at the races. I can get it to pair and have then ridden fine with it...but the next day I switch on the Garmin 500, give the crank a few spins, nothing. Give it a few more...nothing. Go mad for 5 minutes, nothing. The solution seems to be to take the battery out, put it back in, re-pair the 500/sensor (which takes a few minutes) and then all is fine. However, I expect to just get my bike out, a few spins and then ride off.

I know Garmin are good with warranty but, before I resort to that, am I missing an easy trick to wake the thing up before a ride? Many thanks.

dabber

The battery terminals aren't a bit corroded are they? Just thinking that if taking battery out and then refitting resolves it it might just remake a decent connection for a while, which then deteriorates after being left overnight.

Bobbinogs

Not a bad idea Dabber but the thing is only a week old. Does sound like a connection issue though, thinking about it. Might have a little play...

Lookyhere

i had a new 520, the new cadence sensor would take forever to pair and i needed to dis/con the battery like you.

i replaced the battery, a 2032, with a new one - all has been good for the last 3 months.

tbh of the 3 ant devices the unit pairs with, the Cadence is the one that always take the longest to wake up, this is exactly the same with my daughters 520 as well.

ayjaycee

Mine was bad news out of the box as well. I just changed the battery and It was AOK (and has been for about 9 months since). If that doesn't work, suggest just sending it back for an exchange.

Bobbinogs

Just to close this off as the issue appears to be all fixed.

Thanks to the tip-off from Dabber, I checked the battery and then placed a small piece of paper on the +ve side, effectively forcing the battery towards the internal contacts on the -ve side (actually, the + & - contacts are on the same side of the battery in this design, with the -ve being central and the +ve being off to one side). The sensor has now been in place for a couple of days and, whenever I turn the cranks a few revolutions, the green lights flash indicating the unit has woken up. The little trick there is not to spin too quickly or slowly, just at a comfortable pace for a hand.

The 500 unit worked well with the sensor last night and the results were consistent and plausible.

dabber

Great, Glad to hear you've managed to fix it.

drlodge

Slightly related... I replaced the HR monitor battery some while back, the old one was working fine but quite old so thought a fresh battery would be a good idea. I just could not get the HRM working again. Found out the new battery was as flat as a pancake. Ordered a new battery, tested it for voltage before installing and it worked fine.

These devices don't like dodgy batteries or a general lack of juice.

StillGoing

When I replaced my old GCS10 sensor for the new sensors a few years back, the cadence sensor wouldn't work out of the box. Turned out the battery it came with was flat.