erratic speeds/ erratic power measurements
Posted: Wed Apr 29, 2009 9:09 pm
Hi guys,
I've got two running problems with my isport (I've purchased the ibike pro upgrade so I can download the data once I get a reply).
to compare, my cadence sensor is rock steady accurate.
1. I get erratic / very inaccurate speeds. I am certain, simply converting from gear and candence, that I am not cruising with minimal effort at 45+ kph (yeah, I wish I could, but those are speeds I am working my ass off for). Add to this, I have done a few rides of highly accurately measured distance and I get a significantly longer distance. my standard bike ride to work is 5.7 km and this morning, my ibike registered 6.4km.
2. I am getting very very erratic power measurements. yesterday during my fitness ride it had me chugging at 250-350 watts for the first 10 minutes... then when I started heading home, it had me between 50 and 100 watts. I don't I"m not as strong as 300 watts, even for 10 minutes, and I'm not as weak as 50 or 60 watts if I'm moving at 20 mph + in calm wind conditions.
I did do only 2 coast down rides but the cda it displays is pretty close to teh accepted level for my size (0.46 I think) and crr I just set to 60.
At first I thought the erratic signals were due/could be due to my reflectors on my front wheel but even after removing them I still have problems. I do have another sensor on the opposite side of my front fork for my old bike computer but I removed it's magnet to prevent noise. Could the sensor itself cause interference?
I've got two running problems with my isport (I've purchased the ibike pro upgrade so I can download the data once I get a reply).
to compare, my cadence sensor is rock steady accurate.
1. I get erratic / very inaccurate speeds. I am certain, simply converting from gear and candence, that I am not cruising with minimal effort at 45+ kph (yeah, I wish I could, but those are speeds I am working my ass off for). Add to this, I have done a few rides of highly accurately measured distance and I get a significantly longer distance. my standard bike ride to work is 5.7 km and this morning, my ibike registered 6.4km.
2. I am getting very very erratic power measurements. yesterday during my fitness ride it had me chugging at 250-350 watts for the first 10 minutes... then when I started heading home, it had me between 50 and 100 watts. I don't I"m not as strong as 300 watts, even for 10 minutes, and I'm not as weak as 50 or 60 watts if I'm moving at 20 mph + in calm wind conditions.
I did do only 2 coast down rides but the cda it displays is pretty close to teh accepted level for my size (0.46 I think) and crr I just set to 60.
At first I thought the erratic signals were due/could be due to my reflectors on my front wheel but even after removing them I still have problems. I do have another sensor on the opposite side of my front fork for my old bike computer but I removed it's magnet to prevent noise. Could the sensor itself cause interference?