AeroPod, PowerPod and Newton

I have experienced this a few times now and it is a bit annoying.

Basically, I start my ride out with a good wind calibration. I even validate it before I start riding.

Then very early in the ride I notice my power readings are looking a tad off. Sure enough when I check the wind calibration it is showing a pretty steady head or tail wind in absolutely calm settings.

Anyone else seen this before?

Me too -

Except I see it regularly. I get my set up, zero out the wind and then maybe even just move 100 feet and I get an offset - battery life has nothing to do with it - can be new or old. I can auto wind inside - no big temperature change to go outside and then check the cal wind and had a drift. Cover up the port, and cal wind again, may have to hit the button more than once to get a zero. Three miles down the road and I am riding into a light headwind and the meter is telling me I have a 5 mph tail wind.

I see the same even when I am riding on a windy day and can get a tailwind (or calm reading) into an 8mph headwind. I have good values for my wind scaling and CdA. I usually find that in the auto route, I will end up with a wind offset of -2.5 to -3.5 on the corrected wind.

Tom

Do you always show a tailwind?

What was the temperature during your rides?

How long have you experienced this?

Scott -

It does seem that I almost always end up with a negative adjustment to the wind.
It will vary, but usually I find -2 to -3 as the offset.
Tom

Keep in mind that the number being shown on the wind offset screen is not mph of wind but a reading in pascals. I can't remember the exact formula, but showing a wind offset of -2 isn't going to majorly influence your watts.

One thing that may also be happening is that going into the sunlight as you ride the unit heats up a bit and this can slightly change the wind offset. Usually around 15-20 minutes into a ride at a stop sign I'll check this as it only takes 5 seconds (especially since the wind cal screen is the first screen that pops up when you enter setup mode).

Coach -

Many of my rides are corrected for wind offset during analysis - here there is a -2 to -3 mph shift. This is worth maybe 10 watts or a little more.

OK - so half the data shows what are essentially mph values - the plot - and then the offset is in Pascals.

Tom

lorduintah wrote:Many of my rides are corrected for wind offset during analysis - here there is a -2 to -3 mph shift. This is worth maybe 10 watts or a little more.

Don't confuse mph with Pascals (N/m^2)... though they may be pretty close for most rides.

Looking at my hilly ride file from yesterday, a 1.0 change in wind offset (in Pa) changes the average power by 7W (3.3%), and a 1.0 change in average wind (mph) changes the average power by 4.7W (2.2%).

It's difficult to get any better accuracy. If you are seeing a -2 to -3 mph shift then this indicates that your Wind Calibration is off. I check mine regularly... it's easy to do.

I've seen this problem in the last three or four days with my Gen iii. My un-compensated offset is a 20 to 30 mph headwind for a out-and-back ride. Software on the computer zeros the mean wind speed, but I am left with little faith in the result and no faith in power readings while on the road.

What's changed? I'm riding at 50-60 deg instead of 80+ deg (when I did coast-down rides), and I noted that there was sum crud in the pitot tube input. I used a tissue with alcohol and nail file blade to wipe that area down. Haven't had a chance to test since then.

I'm *very* interested if this is an aging problem with the sensor, or if it's temperature related.

Charlie

Temperature has plummeted here too and my last ride showed some very funky wind data... Device was left out to acclimatise prior to ride and is using a new battery, but wind was very wrong for this ride even though the day was essentially calm... I too am wondering about cold affecting the accuracy...

cwwees wrote:I'm *very* interested if this is an aging problem with the sensor, or if it's temperature related.

Temperature effects on the offset are easy... zero it, put it in the freezer and see what happens, put it under a lamp and see what happens.

You are getting a 20-30mph net headwind....? That's crazy. Obviously your wind scaling is way too high.

I noticed some irregularities with the cooler temps lately myself. Before when it was 90-100+ degrees my unit would always zero out for the wind cal. Now that it is cooler it seems that I have to do it multiple times through the ride. I still get good numbers but I do not like having to do it 3-4 times. To bad the unit would not adjust itself for the temp changes instead of us haveing to do wind resets.

Same again today... entire ride shows a large tailwind even though that was not the case... (it was mainly calm but with some sections of strong head/crosswind towards the end) And first few minutes power was completely off (way too much power for effort by >100w).

Analyse route removed the initial power spikes so it looks like the software could see there was a problem, but the wind remains unchanged.

Personally, I'm going off the iBike. It's a great concept but doesn't seem to handle real world conditions well? Too many variables lead to uncertainty. One has no idea if the cal ride is correct (it either works or it doesn't?!) and then road surface conditions (as reported elsewhere) cause incorrect/zero results and now the cold is throwing the unit off completely; it's going to be colder yet and for the next four months... :/

Your iBike is mis-calibrated.

The reason your watts are high for the first 5 minutes is because either your Tilt Cal is wrong or your riding tilt (measured by your Cal Ride) is wrong. The iBike figures out the problem after 5 minutes and fixes things automatically.

The reason you show a constant tail wind is either because a Cal Wind wasn't done prior to the ride or, more likely, because a new Cal Ride needs to be done. Your wind scaling factor is about 1.0 in your profile; based on your ride data it probably needs to be around 2.5. I believe your iBike is mounted on your handlebars; this WSF is consistent with this location.

You should get much better results after doing a new Cal Ride (preceded, of course, by a Tilt Cal and Cal Wind).

Please post a ride file after you've done a new cal ride.

John,

You have previously commented that my calibration was fine...? And nothing has changed since then... This problem has occurred only on the last two rides where temperatures have dropped below 10 degrees. Nothing else has changed and all previous months rides gave generally consistent results. And interestingly, I own a Wattbike, which gives me very similar watts at my lactic threshold as the iBike, suggesting a good correlation (in certain circumstances, I guess).

And If my cal is wrong, it goes back to what I said above about user frustration relating to uncertainty with the iBike; there's no way to know if the cal is wrong or not... I did a four mile out and back on a flat surface and then a bunch of coast downs... it was a warm day, but there was some head/tail wind on the course (it's rare for there not to be around here). I don't see what I could have done differently? And if indeed wrong, my last few months of data is garbage? :/

Could you please take a look at my Cal components and see if you really think there's a Cal problem and, if so, which components are out?

Bike: Focus Izalco
Tyres: Continental Gran Prix Four Season
Rider: 6'1
Weight: 166 lbs
Bike+Rider+Kit: 193 lbs

GWPOS wrote:I noticed some irregularities with the cooler temps lately myself. Before when it was 90-100+ degrees my unit would always zero out for the wind cal. Now that it is cooler it seems that I have to do it multiple times through the ride. I still get good numbers but I do not like having to do it 3-4 times. To bad the unit would not adjust itself for the temp changes instead of us haveing to do wind resets.

How much is it off when you need to zero it during a ride?

Mark_H wrote:And If my cal is wrong, it goes back to what I said above about user frustration relating to uncertainty with the iBike; there's no way to know if the cal is wrong or not...

Actually, there are some simple ways to check your calibration.

If the Wind Scaling is off, then you will see a significant net wind on your rides when there shouldn't be any.
If your Wind Offset is off, you will see the number deviate from zero.
If your CdA is off, then you'll get significant and fairly consistent +- watts while coasting at higher speeds.

rruff wrote:

Mark_H wrote:And If my cal is wrong, it goes back to what I said above about user frustration relating to uncertainty with the iBike; there's no way to know if the cal is wrong or not...

Actually, there are some simple ways to check your calibration.

If the Wind Scaling is off, then you will see a significant net wind on your rides when there shouldn't be any.

Where am I looking for this?

If your Wind Offset is off, you will see the number deviate from zero.

Where am I looking for this?

If your CdA is off, then you'll get significant and fairly consistent +- watts while coasting at higher speeds.

Where am I looking for this?

Mark

It's easy to say the wind scaling off. Why have I been able to use this calibration for ten months, and *now* the wind scaling goes *noticeably* off within a week? I've done about 15 cals over three years and gen i, gen ii, and gen iii iBike Pro's. I get confidence from seeing the numbers fall *close* to previous calibrations. This one has been a good calibration, until... What changed two weeks ago?

Charlie

rruff wrote:

cwwees wrote:I'm *very* interested if this is an aging problem with the sensor, or if it's temperature related.

Temperature effects on the offset are easy... zero it, put it in the freezer and see what happens, put it under a lamp and see what happens.

You are getting a 20-30mph net headwind....? That's crazy. Obviously your wind scaling is way too high.

John noticed this:

"Your wind scaling factor is about 1.0 in your profile; based on your ride data it probably needs to be around 2.5. I believe your iBike is mounted on your handlebars; this WSF is consistent with this location." When he says this WSF he means the 2.5.

Was your prior profile that worked so well actually 1.0? I have to hear of any units being properly cal'd at 1.0. This says to me that somehow your iBike profile has gotten hosed, clobbered or corrupted somehow.

Can you look back at a save profile and check this?

Hope this is it!

Russ

Mark_H wrote:John,

You have previously commented that my calibration was fine...? And nothing has changed since then... This problem has occurred only on the last two rides where temperatures have dropped below 10 degrees. Nothing else has changed and all previous months rides gave generally consistent results. And interestingly, I own a Wattbike, which gives me very similar watts at my lactic threshold as the iBike, suggesting a good correlation (in certain circumstances, I guess).

And If my cal is wrong, it goes back to what I said above about user frustration relating to uncertainty with the iBike; there's no way to know if the cal is wrong or not... I did a four mile out and back on a flat surface and then a bunch of coast downs... it was a warm day, but there was some head/tail wind on the course (it's rare for there not to be around here). I don't see what I could have done differently? And if indeed wrong, my last few months of data is garbage? :/

Could you please take a look at my Cal components and see if you really think there's a Cal problem and, if so, which components are out?

Bike: Focus Izalco
Tyres: Continental Gran Prix Four Season
Rider: 6'1
Weight: 166 lbs
Bike+Rider+Kit: 193 lbs

Honestly this is the number one issue of IBIKE for me, I now have 11 different training profiles from my 10 months of use on the IBIKE. When do my profiles go wrong? Every time it rains !!! I went through the process with Aaron to try and fix the issue but honestly why would I send the unit back when after I do the next cal ride and coast downs its fixed again the unit itself is fine....There is a technical explination somewhere here for what I would call Profile creep but no-one seems to know the answer.

PS Still waiting for the good ole Boyd Wizard.

Signed,
A slightlty disgruntled user !

Avanti wrote:

Mark_H wrote:John,

You have previously commented that my calibration was fine...? And nothing has changed since then... This problem has occurred only on the last two rides where temperatures have dropped below 10 degrees. Nothing else has changed and all previous months rides gave generally consistent results. And interestingly, I own a Wattbike, which gives me very similar watts at my lactic threshold as the iBike, suggesting a good correlation (in certain circumstances, I guess).

And If my cal is wrong, it goes back to what I said above about user frustration relating to uncertainty with the iBike; there's no way to know if the cal is wrong or not... I did a four mile out and back on a flat surface and then a bunch of coast downs... it was a warm day, but there was some head/tail wind on the course (it's rare for there not to be around here). I don't see what I could have done differently? And if indeed wrong, my last few months of data is garbage? :/

Could you please take a look at my Cal components and see if you really think there's a Cal problem and, if so, which components are out?

Bike: Focus Izalco
Tyres: Continental Gran Prix Four Season
Rider: 6'1
Weight: 166 lbs
Bike+Rider+Kit: 193 lbs

Honestly this is the number one issue of IBIKE for me, I now have 11 different training profiles from my 10 months of use on the IBIKE. When do my profiles go wrong? Every time it rains !!! I went through the process with Aaron to try and fix the issue but honestly why would I send the unit back when after I do the next cal ride and coast downs its fixed again the unit itself is fine....There is a technical explination somewhere here for what I would call Profile creep but no-one seems to know the answer.

PS Still waiting for the good ole Boyd Wizard.

Signed,
A slightlty disgruntled user !

Also interesting to note that looking at my first ever profile values were on my handlebar mounted unit:
Aero 1.075
Wind Scaling 2.999
CDA 0.359
Friction 8.935
CRR 0.0059

Now 11 profiles later
Aero 0.436
Wind Scaling 1.148
CDA 0.379
Friction 7.965
CRR 0.0059

I've changed the last set up to estimated to Estimated friction as I read on the forum this is providing better profiles, I'm up for anything to try and help fix the issue.

How much does changing my current accurate profile to my first ever profile actually change a rides results well its huge:
Accurate Profile: AVG Power 187.2 watts
First Profile: AVG Power 329.5 watts

So every profile I've done my Numbers slowly get less and less I'm expecting that in 12 mths I'll be talking about a windscaling factor of 0.400 or something along those lines.

John any feedback?

Russ wrote:John noticed this:

"Your wind scaling factor is about 1.0 in your profile; based on your ride data it probably needs to be around 2.5. I believe your iBike is mounted on your handlebars; this WSF is consistent with this location." When he says this WSF he means the 2.5.

Was your prior profile that worked so well actually 1.0? I have to hear of any units being properly cal'd at 1.0. This says to me that somehow your iBike profile has gotten hosed, clobbered or corrupted somehow.

Can you look back at a save profile and check this?

Hope this is it!

Russ

I've been using the same Cal since August when I received the iBike, with WSF of 1.09. If I copy my current profile and adjust Wind Scaling to 2.5 and then apply it to the 'borked' ride, it does indeed look much better. But if I then apply that profile to all my previous good rides they are VERY clearly wrong; they suddenly show very strong headwinds for the duration. I've attached a ride from September, which uses the same profile as 'borked' and yet whose wind profile much better reflects what was happening on the road that day. Difference? About 10 degrees C...

My WSF may be off (but if so, why?) but I don't think it's the culprit. If I were the only one with temperature issues then I'd be inclined to think the fault was at my end, but that doesn't seem to be the case.

My buddy, who also owns an iBike suggested I give the port a good blow as he saw similar problems in the past when his port was blocked by rain (note borked ride was dry), so I've done that and will see what happens on the next ride...

Attached: A good ride from September. Same ride "fixed" with 2.5 WSF. My cal ride data (at least I think it's this file...)

And the cal ride itself:

Mark_H wrote:Where am I looking for this?

Read the manual... search the forums.

Avanti wrote:So every profile I've done my Numbers slowly get less and less I'm expecting that in 12 mths I'll be talking about a windscaling factor of 0.400 or something along those lines.

Since your wind scaling is dropping, that means it is getting more sensitive... which doesn't seem like a bad thing to me. I'd guess it won't drop much further, but who knows.

I check and adjust my WS pretty often since it does wander. If you understand what it is, it's easy to adjust based on the data in the " analyze wind" screen in the software, after doing a few out-back laps. An indicator that something is wrong is if you get a net wind on your rides that doesn't make sense, and your wind offset is ~0.

Once you get your CdA and Crr values nailed, there is no reason to redo the cals for those... just adjust the wind scaling factor when necessary.

Russ wrote:John noticed this:

"Your wind scaling factor is about 1.0 in your profile; based on your ride data it probably needs to be around 2.5. I believe your iBike is mounted on your handlebars; this WSF is consistent with this location." When he says this WSF he means the 2.5.

Was your prior profile that worked so well actually 1.0? I have to hear of any units being properly cal'd at 1.0. This says to me that somehow your iBike profile has gotten hosed, clobbered or corrupted somehow.

Can you look back at a save profile and check this?

Hope this is it!

Russ

I re-calibrated yesterday - for both bikes. The heavier bike (handlebar mount, nearly level) has 3 calibrations on record with WSF of 2.5, 4.0, and 3.5. The new calibration is now 1.04 or something. The light bike (stem mount with a 17% grade offset), has been running about 0.6 to 0.7 WSF for all calibrations. This one was about the same.

If something changed in the iBike, I'd expect both to change. Only one of the two bikes changes WSF in calibration?

Charlie

rruff wrote:

Mark_H wrote:Where am I looking for this?

Read the manual... search the forums.

Yeah, very helpful, thanks

One of the big problems with iBike, from a user perspective, is that all of these insights and nuggets are scattered about the place and only known by a few cognoscenti who choose to disseminate, or not, which makes for a frustrating experience. As a user you have no idea if your calibration numbers are good (but on the other hand should there really be any question - the device works or it doesn't?), and no handy resource to check questions against without trawling hundreds of posts for obscure tidbits. The user manual is often too brief in it's descriptions of some things leaving more questions, than answers. There should be a sticky in the forum that collates all these common queries to help users out?

I agree it's tough... but the VC guys have their reasons I guess. This might get you started:
http://www.ibikeforum.com/search.php?ke ... mit=Search

If I have time I'll try to put together something a little more comprehensive.

There's nothing we want more than for our instructions and advice to be clear, helpful, and easy to find.

We try to communicate with customers in as many ways as possible:

FAQ on our website
Indexed, detailed instructions
Illustrated instructions
Detailed help menus in the iBike software
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Forum
Live tech support 7 days a week
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For those of you who are veterans, you'll know that we update these things regularly, and in response to customer requests.

Sometimes we're told we are too detailed, other times that we're not detailed enough...

Despite all this, not for a moment will we say that we've done the best that we can do. So, if you can be more specific about the nuggets and insights you'd like to have compiled, we will do our best to respond.

I have also started to have problems with the wind calibration recently on my Gen III ibike. I upgraded to a Gen III in August and it was giving me credible readings until the past two or three weeks.

During a ride the unit will start reading either a massive headwind or tailwind. I have attached a file where a little after an hour of riding a massive tailwind appears. At the end of this ride I did a short out and back ride which confirmed what I already knew. On the way back home from the short out and back ride I also encountered a 70 to 80 mph wind gust according to the Ibike.

I have emailed Aaron Timmer at Ibike and he has suggested doing a hard reset. Hopefully that will solve my problem.