Related
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Using speed Sensor 2 (w/ Edge 520) on turbo trainer - erratic speed

Kavman
over 3 years ago

Hi.

Bought a Speed Sensor 2 to use on my Canyon Endurance and Tac-X dumb trainer (Ultegra chainset, but using a Shimano drop-in wheel and 105 cassette for training purposes).

Paired fine, but speed seems to be very erratic, dipping to c.50% of actual every 3-5 seconds and then jumping back.

I've tried new battery, some padding in the battery connection, re-pairing, re-positioning, turning off unit blue-tooth etc.

Read a lot about magnetic interference, but can somebody tell me it the below readout is symptomatic of interference or a faulty unit?  Only advice from Garmin was to take it out on the road and test (which is a faff (as I'm now set up for indoor trainer), so keen to know if anybody else has experienced this and possible solutions). If it is interference, then it's a bit of a dealbreaker!

Thanks

  • +1 over 3 years ago

    The problem is that Garmin insists on using a magnetometer as a measurement principle, probably this type of sensor suffers a lot of interference from the moving magnets present in most trainers. I don't understand the reason for this choice, Garmin itself uses accelerometers in the cadence sensor as well as speed sensors from other manufacturers also use accelerometers as a measurement principle.

    source: support.garmin.com/.../

  • 0 over 3 years ago in reply to daniel.schmidt

    Hey Daniel, thanks a lot for your response.  Through some trial and error, I think I've confirmed that it's the trainer causing the interferance (i.e. running the wheel off-trainer seems to eleviate the problem!)  You've mentioned other manufacturers - Do you have a recommendation on a speedo that will work successfully on this sort of dumb trainer and link with an Edge 520? Many thanks, appreciated.

  • +1 over 3 years ago in reply to Kavman

    I am using the Stages Speed Sensor on a dedicated wheel for internal training. For outdoor training I am using a Garmin on the front wheel.

    link: store.stagescycling.com/STAGES-SPEED-SENSOR

    But this sensor is not perfect, I have noticed some drops (communication failure) in some training sessions.

  • 0 over 3 years ago in reply to daniel.schmidt

    Hey Daniel, that’s awesome. Thanks for the advice - will check it out and hopefully make my dumb trainer a little less dumb! Appreciated. 

  • 0 over 3 years ago in reply to daniel.schmidt

    Just to confirm that I tried the Stages Speed Sensor and it seemed to play nicely with my dumb turbo (Tac-X) and Edge 520.  First attempt, but promising results  shown in GC grab below.  Thanks for your advice on this @daniel.schmidt. Hopefully helps anybody else with similar Turbo Trainer challenges.

  • 0 over 3 years ago in reply to Kavman

    I just got the garmin Speed Sensor 2 and it also gives flaws, although different to yours: I use it with the Elite Tuo. So hopefully it will be work better outside!

     

  • 0 over 3 years ago in reply to 2472801

    Good luck!  The Garmin SS definitely never worked with my turbo - the electro magnet threw it out massively.  FYI, switching to the Stages Speed Sensor worked fine with the turbo and remained accurate (although I've now switched to a Wahoo Snap anyway, so no longer a problem as this tracks speed OK).  The Elite Tuo is a nice looking beast BTW!