Problems with profiles when wheel sizes are different, bug?

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grouter
Posts: 10
Joined: Fri Feb 16, 2018 6:25 am

Problems with profiles when wheel sizes are different, bug?

Post by grouter »

Hi this might be one for John I think.

I have two bikes with two profiles my road bike has a 700c wheels and my recumbent has a 20" front wheel with the speed sensor fitted. Both bikes have different speed and candence sensors but both profiles share the same heart rate monitor. The problem I have noticed is when I let powerpod select the profile from the sensors rather than setting the active profile in Isaac. Even though the profile loaded with the ride is correct one it uses the wheel size from the previous bike. I'll try to explain. Last Friday I had a ride on my recumbent with the 20" wheel 1452mm circumference. I set the profile in Isaac before going for the ride so it was OK.

On Monday I went for a ride on my road bike PP picked up the sensors and I was good to go, I checked the active profile in Isaac before leaving and it was the correct one by going into edit profile and loading the active profile in to Isaac. During the ride I noticed the power was low and when I got home I uploaded the file in to Isaac. The file was called xx_48_miles.ibf the average speed for the ride with my Garmin was 17.9mph but in Isaac it was something like 12.4mph. I also noticed the total distance was only 33.28miles even though the file is had 48 miles in the title so it knew I had ridden 48miles. To fix this I have to update the wheel size to 3035mm circumference from 2105mm under analyze device settings. The ratio of these two is the same as the ration of the 700c wheel to my recumbent wheel i.e 1452/2105 = 2105/3035 = ~.69. So even though the ride has the correct profile it has used the wheel size from the previous bike to calculate speed and power. I have attached the IBF with the incorrect calculation and also after I have fixed it.

I'm wondering if this is either a bug in the firmware/Isaac or the common heart rate strap is causing the confusion.
iBike_03_26_2018_1433_48_Miles_HiDef_fixed.ibr
(1.9 MiB) Downloaded 204 times
iBike_03_26_2018_1433_48_Miles_HiDef.ibr
file with incorrect calculations
(1.9 MiB) Downloaded 198 times
Hope this makes sense
grouter
Posts: 10
Joined: Fri Feb 16, 2018 6:25 am

Re: Problems with profiles when wheel sizes are different, b

Post by grouter »

Hi all I did another ride today and this time a used Isaac to set the profile and it did the same thing.
Here is the ride file it was actually 73.4 miles but PP only logged 51miles as again it was using the wrong wheel size to calculate power etc.

I am going to reset the powerpod and just load the road bike profile up. Can somebody at velocomp please look into this it mean I can use th eunit with two different bikes which kind of defeats the object really.

Here is the ride file
abberton_04_01_2018_0759_72_Miles_HiDef.ibr
(1.94 MiB) Downloaded 198 times
If you load the file and change the wheel size to 3035 it will be correct
Velocomp
Velocomp CEO
Posts: 7793
Joined: Fri Jan 11, 2008 8:43 am

Re: Problems with profiles when wheel sizes are different, b

Post by Velocomp »

I'm not sure what is going on here...

Please post a ride file from your road bike, and another ride file from your recumbent. I will use the ride files to compare profiles.
John Hamann
grouter
Posts: 10
Joined: Fri Feb 16, 2018 6:25 am

Re: Problems with profiles when wheel sizes are different, b

Post by grouter »

Hi John. Some more information I think everything was Ok until I had to change the tyre on my recumbent after the original was damaged. The tyre was changed from a 406-35 to a 406-28 so I updated the recumbent profile to reflect this I think it started to go wrong after that. Before this It was OK but I always switched from Isaac in case the heart rate strap affected it.

Original 406-35 tyre both profiles seemed Ok at his point
iBike_02_25_2018_1452_20_Miles_HiDef.ibr
(911.73 KiB) Downloaded 214 times
After modifying tyres size and tweeking CDA ( ignore the first 8 mins while the unit recalibrated gradient )
Fujin_03_23_2018_1305_34_Miles_HiDef.ibr
(1.16 MiB) Downloaded 193 times
Subsequent road bike ride where wrong wheel size used for calculations but profile shows 2105 circumference. Rides was 48 miles at 17.9mph average
iBike_03_26_2018_1433_48_Miles_HiDef.ibr
(1.9 MiB) Downloaded 206 times
Could the issues be caused by tweeking profile maybe. BTW I have now reset and doe a cal ride on my road bike. I have not set up my recumbent again yet.

G
Velocomp
Velocomp CEO
Posts: 7793
Joined: Fri Jan 11, 2008 8:43 am

Re: Problems with profiles when wheel sizes are different, b

Post by Velocomp »

Your ride files from 2/25 and 3/23 have the same wireless ID (combined speed/cadence sensor). Hopefully they are from the same bike...both are profile 1

2/25 ride file has 1490 circumference. 3/23 ride file has 1453 circumference.

The 3/26 ride file has different speed and cadence sensors. Wheel circumference is 2105mm. However, its wind calibration is incorrect. This is profile 3.

Do you have anything stored in profile 2?
John Hamann
grouter
Posts: 10
Joined: Fri Feb 16, 2018 6:25 am

Re: Problems with profiles when wheel sizes are different, b

Post by grouter »

Hi John, Profile 2 was empty. BTW the recumbent bike ( combined sensor ) is profile 3 the road bike is profile 1, so I'm not sure how they got switched when you extracted them, when I extract them from the ride files here they're the right way around or at least it tells me I already have a profile with that name.

On the third ride it's not the wind calibration that's wrong it's that the powerpod has used the smaller wheel to calculate the speed and therefore distance and power. In the advanced stats the distance shows as 33.28 miles and the average speed 12.4. This is the problem as the ride was actually 48 miles long with an avg speed of 17.9. To correct this you have to update the wheel size in analyse device settings from 2105 to 3035. At that point the road speed matches wind ( roughly ), the distance and speed then also match my Garmin. The ratio of 2105 to 3035 is pretty much the same 1453 to 2105 about .69 hence I'm pretty sure it was using the the smaller wheel size when calculating stats even the profile looks right. If you look at the fixed IBR file here you'll see what I mean.
iBike_03_26_2018_1433_48_Miles_HiDef_fixed.ibr
(1.9 MiB) Downloaded 187 times
grouter
Posts: 10
Joined: Fri Feb 16, 2018 6:25 am

Re: Problems with profiles when wheel sizes are different, b

Post by grouter »

Hi John bumping up again have you had chance the fixed ride file in my previous post yet?
Velocomp
Velocomp CEO
Posts: 7793
Joined: Fri Jan 11, 2008 8:43 am

Re: Problems with profiles when wheel sizes are different, b

Post by Velocomp »

This is confusing.

I think the wise thing to do is to start over. Use Isaac Device/Setup/Reset Profiles to restore all your profiles to factory default. Then, set up each profile for each bike, including pairing and calibration ride.
John Hamann
grouter
Posts: 10
Joined: Fri Feb 16, 2018 6:25 am

Re: Problems with profiles when wheel sizes are different, bug?

Post by grouter »

Hi John I've done that a couple of times now as I'd thought I'd made a mistake. What I would say is that it seems to be OK as long as you don't then go back and update the profiles after initial calibration. I'm always careful to ensure I select the correct profile in the edit profiles window and then re-extract to ensure the changes are correct and have not affected the other profile. I also manually set the profiles before the ride to ensure the correct one is active in case the HR strap is confusing things.

In this instance though cutting the tyre and having to change it seems to have triggered the issue. I don't know if this is relevant but I'm using the Mac version of the Isaac software.

What I can do which seems to have worked before is update the initial profile with the correct tyre size and CDa then go for the cal ride. I'll try that the next time it's not blowing a gale here in the UK and report back.
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