Problems with profiles when wheel sizes are different, bug?
Posted: Tue Mar 27, 2018 4:49 pm
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. Hope this makes sense
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. Hope this makes sense