Wahoo ELEMNT/ RPM speed sensor calibration issues

[Lozi]

I’m looking for some advice about my wahoo setup.

I recently swapped my Wahoo ELEMNT and RPM speed sensor onto my MTB for some winter riding and I have been having some calibration issues.

On the first ride I manually set the wheel circumference albeit slightly wrong somehow (26x1.75 instead of 26x2.00) and the result was bizarre, the wahoo app says I did a 9.3 avg with an 85mph top speed so it’s all over the place. Once onto Strava it calmed it down a bit with a mere 48mph top speed lol

https://www.strava.com/activities/2069264286


I noticed I got the circumference slightly wrong but I doubt that would create that crazy inconsistency, next ride I did I changed the wheel circumference calibration to auto and did a little ride, I was sure I was going faster than it was saying but it was consistent at least. I went out today and it was bonkers again reporting I think more miles than reality, overly slow speed at times and for a while in the middle crazy high speed again (88mph on wahoo app and 56mph on Strava)

https://www.strava.com/activities/2085221608


I really don’t get it, last time I used it on my road my bike back at the end of September it seemed ok, I was always sure it was wrong but it was sensible at least and around what I felt I could do.

Thanks

 

[tom73]

Just a quick question how’s the battery power ? Mine was playing up the last few days on the turbo even though it was showing 1/2 power clearly was not enough power left. Changed it and it’s now working like a dream. Also just check it’s sitting right on the hub. When I put mine back on it still at 1st was acting funny then once I had a look it was not quite sat on curve a quick adjustment and it fixed it. It’s a bit of a fiddle getting on in the 1st place never mind switching it over.

 

[CXRAndy]

Is the the magnetic pickup version or accelerometer version?

 

[Lozi]

Thanks for the replies, I wasn’t aware you could check how much battery it has remaining, I haven’t had it that long I think only since August time I’ve not used it that much.

It’s the accelerometer one.


Also not sure why this has been moved to virtual I’m not doing anything virtual?

 

[CXRAndy]

It’s the accelerometer one.

[/QUOTE]
Its vibration that causes the sensor to give erroneous readings. Ive had the same on the road with high speed readings over slightly bumpy surfaces. I would be doing 30mph then suddenly the speed reading would be 65mph. Ive gone back to the older magnetic pickup version. Wahoo do a combined cadence/speed sensor with magnets

 

[tom73]

Yes using the app. I’ve not had mine long either but it was running low it turned out. You can also tell if The light keeps flashing red every so often and not blue.

 

[Lozi]

That’s pretty crap if it’s vibration doing it you would have thought it could handle that.

I’ll check the battery thanks.