Multiple coastdowns failed

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dtrousdale
Posts: 94
Joined: Fri Jan 11, 2008 2:11 pm
Location: Mountain View, CA

Multiple coastdowns failed

Post by dtrousdale »

I've successfully performed several coastdown and 4-mile ride procedures with my two bikes and my one black wireless iBike. Since I lost 10 lbs. and installed new tires over the past 6 weeks, I decided to do another set of coastdowns and 4-mile ride for my road bike. However, the coastdowns keep failing on the exactly the same quiet street I've been using all along. I cannot think of anything else to try. I changed the battery, performed the tilt and wind offset procedures several times, tried very carefully not to pedal after reaching 20 mph and the word COAST appearing, never changed riding position, tried coastdowns on another street, checked all the setup screens to make sure correct data was entered, etc.
One other thing: I've noticed that the wind offset no longer drifts to 0 like it used to. It seems to drift to anywhere from +3 to +7 and then stop while in my garage even after I've allowed more than 15 minutes of acclimation.
Everything else seems to be working.
travispape
Site Admin
Posts: 392
Joined: Fri Jan 11, 2008 8:52 am
Location: Durham, NC

Re: Multiple coastdowns failed

Post by travispape »

dtrousdale wrote:I've successfully performed several coastdown and 4-mile ride procedures with my two bikes and my one black wireless iBike. Since I lost 10 lbs. and installed new tires over the past 6 weeks, I decided to do another set of coastdowns and 4-mile ride for my road bike. However, the coastdowns keep failing on the exactly the same quiet street I've been using all along. I cannot think of anything else to try. I changed the battery, performed the tilt and wind offset procedures several times, tried very carefully not to pedal after reaching 20 mph and the word COAST appearing, never changed riding position, tried coastdowns on another street, checked all the setup screens to make sure correct data was entered, etc.
One other thing: I've noticed that the wind offset no longer drifts to 0 like it used to. It seems to drift to anywhere from +3 to +7 and then stop while in my garage even after I've allowed more than 15 minutes of acclimation.
Everything else seems to be working.
It sounds like you have tried all the right things. The main thing that can cause cd after cd to fail is if the tilt calibration is off. Are you sure you are doing that correctly--turning it 180 degrees in the process? Could you check the tilt reading on a known-flat surface like a floor in your home?
User avatar
dtrousdale
Posts: 94
Joined: Fri Jan 11, 2008 2:11 pm
Location: Mountain View, CA

Re: Multiple coastdowns failed

Post by dtrousdale »

travispape wrote:
dtrousdale wrote:I've successfully performed several coastdown and 4-mile ride procedures with my two bikes and my one black wireless iBike. Since I lost 10 lbs. and installed new tires over the past 6 weeks, I decided to do another set of coastdowns and 4-mile ride for my road bike. However, the coastdowns keep failing on the exactly the same quiet street I've been using all along. I cannot think of anything else to try. I changed the battery, performed the tilt and wind offset procedures several times, tried very carefully not to pedal after reaching 20 mph and the word COAST appearing, never changed riding position, tried coastdowns on another street, checked all the setup screens to make sure correct data was entered, etc.
One other thing: I've noticed that the wind offset no longer drifts to 0 like it used to. It seems to drift to anywhere from +3 to +7 and then stop while in my garage even after I've allowed more than 15 minutes of acclimation.
Everything else seems to be working.
It sounds like you have tried all the right things. The main thing that can cause cd after cd to fail is if the tilt calibration is off. Are you sure you are doing that correctly--turning it 180 degrees in the process? Could you check the tilt reading on a known-flat surface like a floor in your home?
I just tried the tilt calibration again. It looks to me like it is stuck on 0%, and here I've thought that I had a great spot in which to do the tilt calibration and was doing it perfectly! :cry: I tried doing "bad" tilt calibrations--setting the front wheel on an object 2 inches high, setting the wheel on an object 3 ft. high--and I get the same result: 0%. When I'm in the tilt calibration screen, it will register 0% no matter which way I tilt the the bike: sideways, front, or back. Or this last time, I tilted it front and back in a very exaggerated way, and it registered -0.1% both ways! I put it in the Hill/Wind screen, too, with the same result.

Let me say that this is the first time I've observed the tilt calibration stuck on 0%. Until it usually showed a slight + tilt in one direction and a slight - tilt in the other. I've done quite a number of tilt calibrations, and it has always seemed to work before.

Finally, I tried the wind offset again after the unit had been turned off for a while at it zeroed out this time as it has done before. However, I tried it again later and it would only drift down to about 2 and sometimes down to about 6. This is in my garage with no doors or windows opened.
travispape
Site Admin
Posts: 392
Joined: Fri Jan 11, 2008 8:52 am
Location: Durham, NC

Re: Multiple coastdowns failed

Post by travispape »

dtrousdale wrote:I just tried the tilt calibration again. It looks to me like it is stuck on 0%, and here I've thought that I had a great spot in which to do the tilt calibration and was doing it perfectly! :cry: I tried doing "bad" tilt calibrations--setting the front wheel on an object 2 inches high, setting the wheel on an object 3 ft. high--and I get the same result: 0%. When I'm in the tilt calibration screen, it will register 0% no matter which way I tilt the the bike: sideways, front, or back. Or this last time, I tilted it front and back in a very exaggerated way, and it registered -0.1% both ways! I put it in the Hill/Wind screen, too, with the same result.
I think the accelerometer in your unit failed. Someone will get ahold of you.

Travis
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