Multiple Bike Profiles Missing From Software Roadmap

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  • Official comment
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    Franklin Prince

    Hey Andrew. 

    We would like to introduce multiple bike profile functionality (including various wheel sizes) in a few months. We recognize the usefulness of this, but there are currently some higher priority features we're focusing on concerning the core Karoo experience.

  • Avatar
    Brent T

    Where is the software roadmap, I've searched and cannot find it

  • Avatar
    Andrew Tebben

    Here it is:

    https://www.hammerhead.io/pages/karoo-product-road-map

    It's a bit hard to find on the redesigned website.

  • Avatar
    John Sievert

    I don't think you necessarily need bike profiles, per se (or at least how it is typically done), but I do see the  need to tie the wheel circumference to a given wheel sensor. My issue with bike profiles as a collection of sensors doesn't work if you have wheel sensors and start moving wheels around. But I do like being able to have an odometer reading tied to a specific frame for maintenance reasons and to set the equipment used in Strava and other logging software.

    Also goes without saying that there needs to be an auto calibration of wheel circumference.

    Critical feature?  I can't see how this rises to that level but I could be wrong too.  explain?

    My view is that HH needs to get the display issues resolved ( screen formatting + promised graphical metrics), leverage the Android OS through an app store, and leverage the cellular modem. These are their main differentiators over their competitors  that they have to exploit to gain marketshare.  Incidentally, vis a vis the cellular modem and app store, that's also how they can rapidly support features that they wouldn't be able to develop on their own fast enough.  Then they have the luxury of sucking in features that they see catching on in the 3rd party apps at their leisure.

     

  • Avatar
    Jeremy

    I see this as a critical feature. But only for those who use the Karoo on more than one bike with different size tires. I use a 25mm tire on one bike, and a 28mm on another. If I don't go in and change the wheel diameter every time I switch bikes with the Karoo, then my distance is going to be off (as well as my speed, avg speed, etc.)

    I don't see multiple bike profiles to be the solution. As you said, John, I see having a wheel circumference for each speed sensor to be the solution. Different profiles already exist (and you can make a profile for each bike if you want), but the ability to change the circumference for a speed sensor does not. A global wheel circumference, as it is now, is the problem.

  • Avatar
    Andrew Tebben

    John, Jeremy,

    Thanks for clarifying my original comment. I agree having wheel size with auto-calibration tied to the sensor is the right solution. As Jeremy states, this is critical for those using the Karoo on multiple bikes with different tire sizes

  • Avatar
    John Sievert

    What I would like to see is having the Karoo identify the bike by the sensor set or by a given sensor.  For example, a power meter is tied to a crank usually so if the Karoo sees that power meter paired, then that means it can set the particular bike as data attached to the ride.  That could be a checkbox attribute in the sensor set up. That would be pretty cool, actually.

    The wheel circumference thing was pretty aggravating to me since I have one bike that I ride with 30c tires and the other bike has 25c tires both on 700c rims.  So I did a little math. 

    The circumference from a table for a 700cx30c is 2146.  For the 700cx25c wheel is 2105.  That's a 41mm change or a 1.9% change using the 30c tire as a basis.  So, splitting the difference at 2125mm is a 1% error on the 30c tire and about the same for the 25c tire.  1% deviation is going to be well within the accuracy of just about any reasonable distance measurement on a bike.  So I just set it in the middle and forget about it.  The difference between a 28mm and 25mm tire is even less.  

    Here's the 28mm vs 25mm math:

    700x25x: 2105mm

    700x28c: 2136mm. 

    Difference is 2136-2105=31mm.  Half of that is 15.5mm.  So center between the two is 2120.5mm.  That's an error of 0.7% for both.  

    My advice would be to load the wheel circumference at 2120 and call it a day.  0.7% variance on distance is probably not the largest contributor to the error in distance calculation.  I'd bet that riding a route with a perfectly set wheel circumference and then uploading to Strava and having it correct the distance is probably a bigger error.  On 20 miles, 0.7% comes out to 740 feet or about a block and a half.  I'm wondering (without checking) if tire inflation could have as big of an impact since that also changes circumference.  

    So for road bikes, doesn't really matter.  Now when I switch over to my fatbike here as winter approaches, that's going to be another whole problem and it will matter there when I'm dealing with a 27.5" wheel with a 3.8" tire.

    But I'm as OCD about data as any cyclist, and being an engineer just makes it that much worse.  There is nothing that drives me more nuts than having numbers be off.  But is it an issue as a practical matter?  Not so much.  But I don't want to have to think about it and have it piss me off because it aggravates my OCD data sensibilities.

    But in a market sense, it's a big issue because only data geeks really care about their bike computers.  People who put power meters on their bikes and wear HRM are probably the most geeky about data of all.  They are putting probably near $1000 extra into their bikes to collect that data.  They are willing to pay a premium for a bike computer that manages all of that.  And that is the market and price point that the Karoo is aimed at.  So things like auto calibration are important.  

  • Avatar
    Gordon Davies

    I have ten bikes in running order from 26" , 27" & 29" so that does not help me get the correct milage etc.

  • Avatar
    John Sievert

    Please read it again, especially the phrase "So for road bikes, doesn't really matter."  And specifically, this was addressing the difference between 28mm and 25mm tires on the same 700c rim.  

    Never claimed it was a panacea for all tire and rim sizes nor that it was an acceptable long term solution.

  • Avatar
    Mark Davis

    Question: Does the wheel circumference input matter if I have a speed sensor (Wahoo strapped to the front wheel hub) as the speed sensor doesn't know what sized wheel/tyre it is on?  I believe the speed sensor when paired to the Karoo, overrides the GPS generated speed data?

  • Avatar
    John Sievert

    Yes.  That is when it does matter.  The speed sensor does not report speed, it report revolutions.  So unless the computer knows the circumference of the wheel and tire it doesn't know the distance that has been traversed.

    I believe that is correct - it is correct for every other bike computer I've used - the wheel rpm/speed input takes precedence over the GPS generated speed and distance.

  • Avatar
    Mark Davis

    John, aha, that makes perfect sense to me. This is my first bike computer so hadn't given it too much thought - didn’t realise the Karoo would be doing some calculations in this way. For my 700x25C wheels/tyres, I checked online and if I have read the chart correctly, I have set my Karoo to 83.12in or 2111.25mm.

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    John Sievert

    I didn't check your numbers, but that seems about right to me.  FWIW, if you're uploading to Strava, there is a switch there to correct the distance based on the route ridden.  

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    Florian Buijs

    The easy fix for this would be .... the Garmin way. On my Edge 820 it will automatically set the circumference for a sensor, by using GPS a certain amount of time. After that GPS sync, the circumference is then auto filled in. Works great.

  • Avatar
    John Sievert

    Agree.  It's this way on the Wahoo computers too.  I'm pretty sure it's on their list.  They need to do this.

     

    J.

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    Richard Lytle

    My Karoo has sat in its box since I received it back in April and shockingly discovered it cannot account for multiple wheel sizes (nor does it have odometer totals).  To me, this is critical functionality.  I track total miles on four different bikes, each with its own wheel sensor, and every other bike computer I've previously used has allowed me to easily move the unit between bikes.  I read the Karoo notes every time a new update is released, hoping to learn that multiple wheel size functionality has been added.  Sadly, the development team does not share the same level of priority as I do.  So I will continue to use my Polar V650 and my Karoo will remain on the shelf, unused, until this is added.  

  • Avatar
    John Sievert

    What are the wheel sizes of your 4 bikes?

    You might be surprised at how close they actually are in measurement accuracy.

    While I agree with you that this is something they need to do, when I went through the math I realized that I was really looking at a 1.2% measurement error. My tires range from 25c to 30c all on 700c rims.

    i want the wheel size to track with sensor more than I want a bike profile. 

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    Brent T

    The multiple profiles is important too, as Richard points out, to track miles and stats per bike. The only work around d I have is to edit the activity in Strava and change the bike used, it seems like bike profile could be tied to the data screen sets, then that bike could be uploaded to Strava at the same time. If this could be done even before they build the dashboard or on device tracking, I think it would go along way to easing this pain point.

  • Avatar
    John Sievert

    Yep.  I agree with that.

    To be clear, I don’t think having the wheel circumference track with the bike is a good thing.  I don’t really think we should be worried about wheel circumference at all and it should be an auto calibrating thing anyhow. 

    The other problem, for me, with bike profiles is that they typically presume the same set of wheels.  That doesn’t work well for me since I have multiple sets of wheels and I change them all the time. So a bike profile can tell me how I’m doing on my chain and chain rings but the rest of the drivetrain is tied to the wheels - tires, cassette, etc...  So bike profiles?  Not interested so much - seems like a good idea until I tried and use them.  Mileage on a frame is interesting but not particularly useful except for the chain.  Mileage on wheels is more interesting.  At any rate, the whole thing of trackign maintenance became such a nightmare for those reasons that I just went to more of a measurement based approach.  Replace the tires when they look worn.  Replace the chain when it measures as it needs to be replace.  Lube the chain when it’s either too dirty or making noise.  

    In the interim until auto calibration could be added, I had proposed tying the wheel circumference to the speed sensor and having that entered in the sensor.  I’d still rather have mileage on my wheels than on the frame.

    My point above was that I was surprised at how little difference wheel circumference actually makes.  My gravel bike has 30c tires (Schwalbe G-1 speeds).  My road bike has 25c Clement tubulars.  The differencce between the two comes out to be something like 2.5% in circumference.  I split the difference and go in the middle, tolerating a 1.2% error on distance by wheel RPM recognizing that there are bigger errors in the whole ride measurement than that.  In many cases, it just doesn’t make that much difference.

  • Avatar
    Rob van Baak

    Maybe I am wrong about this. But when using multiple bike profiles you can place a sensor to  the bike where you use it. Like on my road bike I've the RotoR power. Then when I choose my road bike the sensors listed/attached to this bike will be used.
    Now I've different sensors on my 3 bikes. The ones which are on the bike I ride at that moment are connected. And I've the feeling that the computers is and stays searching for the other sensors on my other bikes. This will also cost batterypower...

    And it would be great the karoo recognizes the bike by the sensors connected to it. And then automatically choose the right bike.


    I think...

  • Avatar
    John Sievert

    I don’t think there is any advantage to disabling specific sensors especially on ANT+ which is a broadcast protocol.  There may be on BT but I think it’s minimal.  If there is any advantage it is in turning off the specific radio completely.  In this case, I think there is a savings by turning off BT.

    Running only ANT+ sensors but even with BT radio on, I was able to get to about a 6-7% battery consumption per hour with the screen at around 30% of full bright.  The sensor set was a Garmin wheel speed sensor, Wahoo Tickr HRM and a Wahoo RPM cadence sensor.

    When I connect my Stages power meter in BT, then power consumption ran considerably higher, and around 11-13% per hour. 

    The big unknown here is power consumption that is required by the computation.  For example, if a sensor causes complex calculations that can do as much or more to increase power consumption than the actual communication to the sensor.  DRAM is notorious for requiring much higher power with certain types of access.

    So my ANT+ experience with the excellent power consumption achieved with the BT radio on but no BT sensors I think supportss that fact that little power is consumed by the BT interface looking for sensors.

    This was done measuring off of a full charge and I’m sure different results would result in different parts of the battery discharge curve such as the last 10% of the battery instead of the top 10%.  There are almost certainly inaccuracy in the fuel gauge software at the low end of capacity and I think we’ve seen that with some of the reports of going quickly from 20%  to zero.

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