Wahoo elevation too low

MidlandsGrimpeur2

Slightly random one.

I have just switched to a new winter bike, have done 6 rides so far and noticed that the total metres climbed for each ride is showing at about 200-250 metres too low. Bog standard road bike with 25mm tires (I mention tire width as elevation has always recorded low on my gravel bike, which for some reason I have always put down to this. Could be utterly wrong on my part though!).

I have a Wahoo bolt, no app updates recently which could have affected it, and I have also switched back on to my other road bike for a comparison, and the elevation was back to normal.

I use the same routes and distances, so I know based on hundreds of rides that the normal metres climbed should be around 950-1000m, but it is 700-750 for each ride on the new bike.

Any ideas what may be causing this?

pangolin

Lower handlebars on the new bike?

MidlandsGrimpeur2

Lower handlebars on the new bike?

Other way, slightly higher as I have not had chance to cut down the steerer as yet. Interesting, the gravel bike is higher at the front end as well, which would match up.

Never even thought of this, how would the bar height have such an affect on this?

pangolin

It wouldn't sorry - just being silly. Neither should tyres.

Does this help at all? https://support.wahoofitness.com/hc/en-us/articles/115000441324-Why-am-I-Seeing-Elevation-Differences-in-My-Ride-Data

Is it mounted in the same way on both bikes?

MidlandsGrimpeur2

It wouldn't sorry - just being silly. Neither should tyres.

that one went straight over my head, my joke detector is normally more finely tuned!

Yes, same mount. There is obviously some quirk in the system somewhere, guess I will just have to learn to live with it!

pangolin

Do you consistently use the bikes in different weather? Or to put it another way have you tried the winter bike on a nice day when you'd usually take the summer bike?

MidlandsGrimpeur2

Good thought, I know atmospheric conditions can have an impact. Only had the new bike (with which I have experienced the low readings) for over a week so sample size is small, but I have ridden through two thunderstorms and also a couple of nice bright days as well. Readings were consistently low across each ride.

You might be right about the mount though. I was mistaken, just realised that I had put a stem mount on the new winter bike (which is same as the gravel bike). Whereas, I use the out front aero mount on the summer bike (I thought I had switched this over).

I will stick the aero mount on to the winter bike tomorrow and see if that affects it at all.

trevor.hall12

I know the garmin can be hideously out in bad weather, you can correct it on strava

davebradswmb

My Elemnt Bolt consistently exaggerates the elevation on my rides by somewhere between 5 and 10%. The Elemnt use a barometer to calculate elevation like the Garmin units which should be accurate unless the atmospheric pressure changes dramatically over the course of your ride. In Wahoo's marketing blurb they claimed the units periodically recalibrate themselves against known elevations which should mostly eliminate errors due to changes in atmospheric pressure due to changes in the weather. I can't see how changing the mount could possibly affect its operation, could it be that your old unit was exaggerating the elevation even more than your new unit?

pangolin

davebradswmb said:

My Elemnt Bolt consistently exaggerates the elevation on my rides by somewhere between 5 and 10%. The Elemnt use a barometer to calculate elevation like the Garmin units which should be accurate unless the atmospheric pressure changes dramatically over the course of your ride. In Wahoo's marketing blurb they claimed the units periodically recalibrate themselves against known elevations which should mostly eliminate errors due to changes in atmospheric pressure due to changes in the weather. I can't see how changing the mount could possibly affect its operation, could it be that your old unit was exaggerating the elevation even more than your new unit?

I was wondering if one of the mounts (if there were 2) could be obstructing the holes in the back. I believe it's the same unit.

pblakeney

davebradswmb said:

...The Elemnt use a barometer to calculate elevation like the Garmin units which should be accurate unless the atmospheric pressure changes dramatically over the course of your ride...

I was on a climb during the summer with an incoming storm. I would guess the climb was +7%, my unit said -20%. I was going damned slow for that descent! 🤣
Use the correction feature in the ride app of your choice.

davebradswmb

pangolin said:

I was wondering if one of the mounts (if there were 2) could be obstructing the holes in the back. I believe it's the same unit.

I'm thinking that it would have to make a good seal to prevent the unit reacting to changes in pressure.

MidlandsGrimpeur2

@pangolin I think you were spot on. Did 100km today over a usual route, 990m climbed using the out front aero mount!

I can only assume the mount is interfering with the sensor in some way.

sungod

if it uses a barometric sensor it needs an external port to allow it to measure the air pressure - often a few small holes on the underside where it's less exposed to water/dirt

check that the holes aren't obstructed or clogged