Recurring changes in values

[chrisf]

Hi everyone, I'm wondering about something that is happening with my isport. About every other ride I have to redo the tilt calibration and ultimately, the cal ride and coast down. What I notice is that the wattage seems unreasonably low, so I'll redo everything and the numbers normalize. Is this something that I should expect or is there a problem I'm overlooking. On a possibly related note when I go into the set up mode and check est crr and est cda the values change after a few rides. Not sure if this has anything to do with strange readings but my cst aero is .723 and cst fric is 6.532. I'm trying to figure this all out so I'll have consistent readings. Thanks in advance.

[lungbuster]

I have an iPro and I reset my altitude, wind and tilt before each ride to get consistent results. Not sure about your other issues though.

[tbarczak]

How do you reset your altitude?

[coachboyd]

You shouldn't have to redo your coastdowns and cal ride if you redo your tilt. Also, your tilt will correct itself within 5 minutes of starting the ride. If it's off at the start off the ride that may be the cause of the low numbers that you are seeing, but it will be correct after 5 minutes.

Once you have you profile (coastdowns and cal ride) done you should be good to go, you don't have to do those anymore. If you are doing coastdowns, this will change your aero and friction number.

[chrisf]

Thanks for the reply you guys. Good to know there isn't something completely wacky going on. I was wondering about something after I read it on the forums last night. Is it best to redo tilt before every ride just as you do wind offset, for complete consistency? Thanks again.

[lorduintah]

After you start up the iBike and auto wind cal, by toggling the down arrow, you can get the display into tilt mode. Find a location moderately flat and level and check your tilt - as displayed. Put the bike in an upright position wheels straight; standing on the side of the bike, wedge your foot in front of the back tire and note the displayed tilt. Now turn the bike 180 degrees and try to put the tires in the exact locations they were touching the ground in the reversed direction. (front to back and back to front). If the tilt value is the exact negative of the previous reading or within a couple of tenths - you are set to go - any small differences and the iBike processor will correct. If you have a large difference from the two, then go to setup - holding the up arrow down for 2 seconds - and toggle the display to tilt and do a calibration. It will not be very often that you need to cal the tilt. The wind offset is a different story as air pressure and temperature have more of an effect on this sensor. You can cut this process to one step, in most cases, if you put the tires in the exact same place before you ride and run a check - some people have marked a location for the tires in their garages, for example (only if you ride soon afterwards).

Tom

[lungbuster]

How do you reset your altitude?

Hold the up arrow for two seconds to bring up the menu. Scroll until you get to altitude. Press the center button. The first number will strart flashing. Use the up/down arrow to change numbers and the right/left arrows to move to the next number. When you have put your altitude in press the center button again. Done. Press and hold up arrow for two seconds to return to ibike speedo.
I use my iPhone GPS app when I drive to different areas to get the altitude.
Wayne

[johnhellas]

I have a slightly different problem. My tilt reading (and therefore the watts shown) was accurate on my Gen 1, until I got caught in a bad rainstorm 2 weeks ago. Ever since then, when I set the tilt calibration, it at first goes to zero (ie, tilt is accurate at first) but then right before my eyes it slowly changes and eventually within minutes goes up to 1% and more, thereby eschewing the watts reading when I ride the bike. I suspect the rain affected it although in 2 years I've owned it I have been through rain and this never happened before? WHAT SHOULD I DO? Thanks in advance!

[lorduintah]

1 - hard reset - take the battery out, flip it over and put it back in the battery compartment momentarily the wrong way. You are basically shorting + to - on the unit - no harm there is not voltage - you are draining it off.

2 - check your altitude = the pressure sensor might still be moist and it could be drifting - this can make it look like tilt drift.

3 - leave the battery cover off for a day or two and let the inside of the electronics dry out.

I think these are the most common "fixes".

Tom

[johnhellas]

Thank you Tom, your suggestions worked after a couple of tries.

John