Garmin 810 Cadence Problems

[GmanUK65]

Bought a Garmin 810 a couple of weeks ago. First time out using it, the cadence worked fine, but every ride after this it has been wrong. I am getting high readings ranging from 130 - 160 rpm, I know I am not doing this (I don't think it is possible to do that many revs on a bike). Has anyone else had this problem? How did you fix it?

GmanUK65

 

[HLaB]

It is possible but more likely your rocking the pedals, trackstanding in front of the sensor, back pedalling a fraction and pushing immediately forward or something of that ilk. The only way to 'fix' it is to avoid doing it but sometimes it can be useful.

 

[Roadrider48]

Sensor battery?
My HRM was behaving erratically after being not too old; changed the battery and it has been golden since.

 

[DRHysted]

Also check the distance between the sensors.
Alternatively consider interference, when I go past one house on the Allez my cadence goes haywire. It doesn't happen with any other bike, or anywhere else on my commute.

 

[GmanUK65]

I am not rocking the pedals as I use SPDs and the only time I back pedal is when I am coming to a sharp bend and getting the pedals in correct position. I dont fancy buying a new battery (for the Garmin costing £400, I dont really want to spend more money), and it cannot be interference because it happens all of the time.

Has anyone got any better suggestions?

 

[T.M.H.N.E.T]

More than likely a dodgy sensor, the GSC10 is known for it's ability to be crap

 

[Roadrider48]

A pack of two batteries costs around £5 at Argos. Hardly a massive addition in cost whether it cures the problem or not.
Then least ways you know one way or the other.

 

[Rob3rt]

Are the high readings constantly high, high for substantial periods of time or just random spikes?

You shouldn't have to be buying a battery, I've got 2 GSC-10 sensors, one on each bike, the one on my road bike has been there 3+ years without a change of battery and the one on my TT bike is coming up to about 18 months, again battery is fine and I don't ride sparingly (both sensors have had hundreds of hours of use, the one on the TT bike has seen 400+ hours of use this year)! That said, being so reluctant to spend a £1 on a battery after spending £400 on the main device is a funny attitude, in for a penny, in for a pound!

If the sensor has been installed correctly (I am not assuming either way) and you are not stopping with the crank arm near the sensor at lights, i.e. if you set of with your right leg forward, it is not out of this world to consider your left crank is near the sensor, as such any small movements may be triggering the sensor and causing high readings, much like if you stop the bike with the wheel magnet near the sensor and you get silly speed readings even if you are stood still, then just take/send it back to where you bought it and ask for an exchange. If you are outside of this no quibble period, contact Garmin direct and if, after following their procedures it still doesn't work, they will most likely just post you a new one.

 

[HLaB]

I am not rocking the pedals as I use SPDs and the only time I back pedal is when I am coming to a sharp bend and getting the pedals in correct position. I dont fancy buying a new battery (for the Garmin costing £400, I dont really want to spend more money), and it cannot be interference because it happens all of the time.

Has anyone got any better suggestions?

I wouldn't rule it out, if you've got spds its easier to do, but it not a massive back pedal its just small movements that triggering the sensor like Rob says; it very easy to do it subconsciously.