Wahoo Elemnt Bolt - Sensor and Elevation Accuracy Issues
 

I've been using a Wahoo Elemnt Bolt with the Wahoo speed, cadence and heart sensors since March of this year (2020). On the whole I really like the head unit, but over time I've been encountering an increasing number of issues.

- The heart sensor started to malfunction after only a few months and had to be replaced under warranty
- The cadence sensor started to malfunction after 7 months and had to be replaced under warrany
- Now the elevation readings on the head unit are totally inaccurate

With regard to elevation, I know accuracy is an issue with many head units. However, my Elemnt Bolt went from giving me elevation that was "in the ballpark" to elevation that is inaccurate by thousands of feet. I'll contact tech support today to see what they have to say. I have to assume this sort of "drift" over time (at least to this extent) is not mormal.

Anyway, I'm curious if this is par for the course with Wahoo or if my experience is more of an outlier? I'm also curious to know what (if any) head units/sensors would be significantly better in terms of accuracy compared to the Elemnt Bolt. Thanks in advance for the feedback!

Every one I have seen has variations from unit to unit. Would be interested in what Wahoo says to you. Thousands of feet is not right.

I just got off the phone with Wahoo tech support and their first inclination was that my "maps" section needed to be updated. Evidently, even doing the regular updates prompted by the head unit doesn't always update the maps (pre-loaded or otherwise) that are in the head unit. It was my understanding that all maps came pre-loaded (which they do) and that any system update would also update the pre-loaded maps. Eveidently, managing maps and their corresponding updates is a process that needs to be handled separately from general firmware updates.

Tech support walked me through the map update process (easy peasy) and they asked that I go for a short ride to see if the problem is fixed. Wahoo also told me that in most cases when there is a hardware issue impacting elevation readings it's usually off by 10s of thousands of feet. Even though my elevation errors are large, they aren't large enough to indicate a head unit issue (at least not at this point).

I'll report back later today as to whether the software update fixed the issue. Fingers crossed. :thumb:

I'd also like to add that dealing with Wahoo support is fast and easy (even thought it's been much more frequent than I would have preferred). They're easy to reach, they do their best to help you out, and they are quick to replace hardware if necessary.

I had forgotten about the manual map updates, thanks for the reminder. Yeah definitely let us know if that resolved it.....although I can't imagine how a map update would fix it because it's not like elevation has changed.

The manual map update did not resolve the elevation inaccuracy issue. The issue is "less bad", so the update seems to have done something, but elevation is still way off. I rode a 36-mile route today that should have had about 150 ft. of elevation and the Elemnt Bolt showed total elevation at 906 ft. That's not as bad as the pre-update elevation for the same route, which was 1,299. . but stll not acceptable. I'll be on the phone again tomorrow with Wahoo tech support. :(

Are you asking about actual elevation of where you currently are or the elevation gain/loss during your ride?

I know Florida is flat, but is it that flat? I go for a 25 mile ride here and I can easily rack up a 800 to 1000 feet of elevation gain and loss. Yet the tallest hill I go up is probably only 80 feet of elevation change, most just 20 feet of change.

I've had bad elevation with my Garmin 520, but not noticed it with my Bolt. Where is the elevation error coming from, throughout the ride or at certain points? Elevation is calculated by using barometric pressure. If you turn it on indoors before leaving or go between environments, put it in a pocket at some point, and such it will drift more. The altimeter port can also get clogged (this happened easily with the 520).

Overall elevation gain/loss has been way off for about 2 weeks and I have no idea why. For the 7 months prior it was pretty accurate. All other functions on the Bolt still seem to be OK.

Where I live the highest point in town is 65 ft.; so yes, it's really flat.

The error seems to be an accumulation of incorrect data over the course of the ride. My Bolt doesn't get turned on until it's outside and mounted on the bike. I also checked the altimiter port and it does not appear to be clogged.

It really isn't a big deal I guess, other than it just bothers me to have incorrect data for my rides. Elevation is not a focus and I never look at my elevation numbers because of how flat it is where I live. It only caught my attention when I traveled a couple hours north for a 100-mile event that had 3,773 ft. of climbing. At the end of the event my Bolt showed 6,049 ft. of climbing. Ever since that day the elevation readings have been wacky.

Yeah, I didn't think it would....it really sounds like a sensor issue. I would call them back and tell them it is just not working correctly. They should switch out the unit for you.

Does your device have a barometric sensor? I didn't see one listed in the spec's on Wahoo's site. Barometric data will give a better and more accurate info, but it is prone to stuff that can make it seem more inaccurate than other methods used by GPS devices.

If your device isn't using a baro sensor, then position accuracy can really throw off the elevation gain/loss that is being accumulated. IE, when you go over a bridge, map data tends to show the elevation of the terrain below, not the bridge even if it's 100 feet higher. As you ride along the side of a hill, if one moment the position shows you on the low side of your actual path then the next moment it shows you on the high side, then you've just climbed whether you actually did or not.

I'm not saying that you might not be having other issue. But often I think many have an expectation of accuracy and consistency of information that will never be there.

Just got off the phone with Wahoo tech support. They're going to send me a new unit, which is both great and disappointing. I appreciate that they did not drag this out making it more difficult than it needed to be. But at the same time it's disappointing that the issue could not be fixed. Wahoo tech support has been great. The hardware... not so great. In 8 months I've had the heart and cadence sensors replaced due to malfunction, and now the head unit. Pretty dismal hardware performance/reliability IMO.

The Wahoo site does reference a barometric port, but I really don't know where it is on the head unit. I checked all ports and openings and nothing is obviously clogged or obstructed. I'll see how things go with the new head unit; but despite Wahoo's willingness to replace malfunctioning items via warranty (which I really appreciate), I will likely not purchase any more Wahoo products.

Yes, it is that flat. I did a 90 miler last year with less than 100' if climbing. Yes, really.

I too live where it's flat, Long Island, NY. Elevation is not something I really care about and I assume, given the nature of GPS elevation being inaccurate by it's very nature. that any data is useless and likely wrong. If I need to know how much elevation I've gained or lost, I look at the RWGPS data, which is based on topo information.

Topo data isn't correct either for elevation gain and loss. You can go up and down many times between the contour lines on a map that represent 10 feet of elevation.

That's part of the issue for all of us users. What do we count as elevation gain and loss? If I go up and down 5 feet twenty times then shouldn't I get 100 feet of gain/loss? If I don't cross a contour line on a topo, then I didn't gain anything.

I decided to bite the bullet and purchase a Garmin 1030 plus bundle. It was on sale at BTD for $539 (~23% off). Bigger screen, much better battery life, tons of features (some that I may never use), etc. etc.

I may or may not keep the new Wahoo Elemnt Bolt, which I'm receiving as a warranty replacement to the unit I purchased 8 months ago. It's an excellent bike computer overall. I've just had more problems than expected with the Bolt (primarily the sensors) and the 1030 plus looks to be a major upgrade. Expensive, yes! But if I sell the brand new Bolt head unit and throw in the cadence and speed sensors, that would knock off a nice chunk of the purchase price for the 1030 plus. I can then purchase a 2nd mount and switch the 1030 plus between bikes.

I had a Bolt, returned it to REI, got a 1030, have used that for 3 years and no issues. It's a reliable and good unit.

Do not expect accurate elevation information. Even with a barometric sensor on the 1030, it's hit/miss.

Let us know how you get on with it.

I have a new computer coming as well (Stages Dash M50). Not because there is anything wrong with my Bolt (Bolt has been fantastic), but I wanted better power metric visuals. I was really considering getting the Karoo 2 but could not find anything that showed it could be configured to display power metrics like the Dash.

Good to know, thanks. As long as the 1030 plus is in the ballpark of accurate that's all I expect.

The Wahoo was pretty good reading elevation until a couple of weeks ago when it became extremely inaccurate. Wahoo couldn't assist with a fix, nor did they have any idea what might have caused the sudden change, so they're replacing the unit. I'm grateful that Wahoo stands behind the product, but in 8 months this is the 3rd warranty claim (2 sensors and the head unit).

You aren't expecting your gain/loss or shown elevation to match when you get back to your starting point are you? It won't if the atmospheric pressure is changing as it always is.

A .1 in. Hg change in barometric pressure is 100 feet of elevation change. The baro sensor in your device has no way of knowing whether the pressure differences it senses is from it changing altitude or simply the atmospheric pressure changing. The are some ways for it to guess and some devices let you help it by adding elevation points. But some devices only adjust once for elevation.

I've had some longer rides where the elevation shown starting and finishing in the same place was 500 or more feet different. I think I've even had a ride where a dry front passed and there was almost a 1000 feet difference. Wish I'd marked those so I could show an example.

I just want the computer to be in the "ballpark of correct" with respect to elevation. I do not have high expectations. I'm in Florida, so elevation really ain't my thang. At the same time, if my actual elevation gain for a 50 mile ride is 157 ft. my bike computer shouldn't tell me I climbed 1,300 ft. This is what I was recently experiencing on a consistent basis with the Wahoo Elemnt Bolt (after it had been tracking elevation correctly for almost 8 months). In a recent 100-mile event with an elevation gain of 3,773 ft. my Bolt thought I had climbed 6,049 ft. Whether I care about elevation or not, no bike computer should be that inaccurate.

But if you go up and down 1 foot 1300 times in the 264,000 feet you just traveled you climbed and lost 1300 feet.

A foot of elevation change in 100 feet and then 1 foot the other way in the next 100 feet will look pretty much like a level road.

I think you're making this way more complicated than it needs to be. The Bolt gave me good elevation readings for 7 months. During the 8th month those readings for the same routes changed dramatically. That's no bueno.

I probably am. But I have trouble believing the land is so flat that you only have 157' of gain/loss on a 50 mile ride.

Admittedly 1 foot of change might be too little for the resolution of the sensor to reliably perceive and should probably be handled as just "noise" in the data. Still, I can't imagine you not having 3 to 5 feet of change regularly and many times on a road in the flattest of routes.

You've obviously never been to southwest Florida. It's flat!!! ;)

And why are you so concerned with elevation loss? You're getting way too lost in the weeds Iride01 . I'm not planning (or even expecting) my routes to be symmetrical in terms of elevation. Even if I gain 157 ft. of elevation over 50 miles and also decend 157 ft. on the same ride my computer is going to tell me I "climbed" 157 ft. It's not going to give me a reading of "zero" because I also "descended" 157 ft.. Yes, I can go into the menu and the computer will show both my elevation gain and elevation loss. And if it's a round trip starting at home and ending at home, my "net elevation" may very well be close to zero... but the topline elevation number is still 157 ft.

I've been all over Florida, both by car and by sea. I used to be based in Miami when I was flying out of there in the late 80's. However I've had relatives on the west coast of Florida longer than that. I know the roads are flat, but as I said, I have trouble imagining that they don't continuously go up and down a few feet vertically for every 100 or so feet you travel horizontally.

The fact you had a consistent number prior and now don't seems to me to indicate it may have started working correctly after having some issues. However I will agree there could be something else up. A plugged up static port, a software change in what the developers decided should count as gain/loss or a bug that didn't get caught and the data from the sensor isn't tallied correctly.

The only reason I talk about gain/loss is that to me the elevation loss completes the picture. No it doesn't cancel out and go to zero. Both gain and loss are unique totals to themselves. Also, by using the gain/loss as a descriptor, I feel it make it very apparent that I am not talking about elevation. Elevation is simply how far above or below sea level something on land is.

edit... oh, I have had people think that elevation gain is just the difference between their starting elevation and the elevation of the place they stopped at. That's another reason I'm in the habit of using the term gain/loss.

I have the cheaper Element. I ride past a 1272' elevation sign on one of my hill rides. It's been 200' off. I wonder if poor sight lines to satellites or weather is the issue. Now, Florida should do much better on those issues, I'd think, but I wonder if you have radio/microwave interference issues?

And not so seriously - I don't mind coming home at a higher elevation, but finding the driveway when I am 50' underground is tough.