Garmin 800 Stupid speeds

Barrzy257

Hi there, having a few issues with my 800. I can be cycling along at a given speed say 19 then the speedo wil jump down to a lower number, say 7, it's not always the same number and does vary. I have done a hard reset, which sorted the auto pause issue, but this is starting to bug me! Sometimes max speed can be way off also, 90.1mph is my top apparently....move over cav! Haha
Any help appreciated
Cheers

slowbike

At a guess you're using it without the speed/cadence sensor?

If so - it's only as accurate as the calculation off the last GPS fix ... it's not always that good - nor was it on the 705.

With the Speed/Cadence sensor it takes the speed from the wheel revolutions - although with the latest firmware release i have noticed a bit of "speed" when the bike is stationary ...

Oh - and Cav won't move over - you have to go round him

antfly

That shouldn't happen, sensor or no sensor. Sounds like it's buggered but if you are using the sensor that could be your problem.

Barrzy257

Cheers for the replies, I'll look at a software update see if I'm up to date. I do have both sensors installed, and it has calculated the wheel size. I did wonder about it dropping the GPS signal but it's in wide open area's? Strange

slowbike

Another possibility is gps signal manipulation - its not near any military bases when it occurs is it?

Although with the wheel sensor it should pickup from there - it is working - lift your wheel and spin - should get a speed despite being stationary.

Lord Jimmy 7th

I had this with mine last year, it was with the sensor not quite being close enough to wheel magnet and so it wasn't picking up every spin of wheel. Check the fit of sensor and magnet.

Barrzy257

Lord Jimmy 7th wrote:

I had this with mine last year, it was with the sensor not quite being close enough to wheel magnet and so it wasn't picking up every spin of wheel. Check the fit of sensor and magnet.

Always the simple things, I shall check later!

simon_masterson

GPS isn't very accurate. In case anyone thought that their Strava statistics had any credibility.