Having issues calibrating ibike

[jslopez93]

I'm really confused as to whether I need to do coast downs with my cal ride and how to best test if my finalized cal ride is really accurate.

Please note that I've had the ibike for a few years now so I thought I was fairly familiar with the whole st up process. My profile from these is drastically different from either the generic set up from the isaac software or the cal ride (have done it twice with or without coast downs.

First off, using the generic set up profile produced very high numbers (light pedaling showing 250+ watts).

This morning I did a few coast downs and a cal ride, then drove out to do a 5 hour ride.

The cal ride went ok without any apparent issues, I went to toe coast down screen to view the numbers and the were, running around the -10/+10 watt range when not pedaling.

before the 5 hour ride, I did a wind calibration before the 5 hour ride but had this weird bug where the watts and tilt were extremely off in the normal ride screens BUT in the set up screens the tilt % was actually normal. Since the ride had already started I just did a hard reset and the numbers stabilized but I was doubtful on the accuracy the whole time.

Anyway this is a lot of rambling but I guess my point in I want to do a good calibration and feel comfortable that it's legit.

Suggestions appreciated.

[Velocomp]

Please post ride files

[jslopez93]

attached

[Velocomp]

The file you posted has a .rar suffix. This is not an iBike file. iBike files end in .ibr or .csv

[lorduintah]

The rar file type is a UNIX compression method - but you may not have enough UNIX experience to decompress - Stuffit Expander will do the job, however - or you can wait for the right kind of file to be uploaded - perhaps just a zip file.

Tom

[jslopez93]

several files had been zipped into one file (a few coast downs, the cal ride and the big ride). I'm attaching as separate files

Since I did a hard reset the 75 mile ride will say it's from 6/5

[jslopez93]

more

[still-chasing]

Got my New mount so I did 3 Cal Ride with Newton. It is mounted on the stem. 2 Cal ride values are close except for tilt. The third one has more significant change.
Here are my 3 Cal Ride values. CDA is fixed at .309 and CRR is fixed at .0055

Aero .265 .268 .310
W. Scale .856 .869 1.003
Fric. 9.196 7.719 6.980
tilt -.7 -.5 -.4

Should I average the Cal rides and manually change values in my profile?
I did tilt calibration before each Cal Ride why the difference?

Am I better off doing coast downs?

[racerfern]

I wouldn't use the last last set of data. Without the ride files there's no way to tell what happened, but with the ride files we might see what changed. It's usually the wind but for sure something changed.

Also, whatever changed, changed from 1 to 2 and from 2 to 3. It's just a bit more pronounced in the last cal ride.

[still-chasing]

Thanks Fernando.
I think I'll do a few more Cal ride to confirm the calibration.
In the mean time, here are the 3 Cal ride files in reference:

I read on your other post that you do 4 Cal rides back to back and then average the values? did I get that right?

Thanks again.

[racerfern]

I read on your other post that you do 4 Cal rides back to back and then average the values? did I get that right?

That is correct, however I do keep in mind that if there is an outlier, I discard it. When you're looking for near perfect conditions over a period of four short cal rides, it's amazing how much things (wind) can change.

[jslopez93]

Looks like my thread's been hijacked a little.

Any feedback on the files I posted?

[racerfern]

Looks like my thread's been hijacked a little.

Any feedback on the files I posted?

Hijacked a little? More like commandeered. Sorry for that, I'll look at them this evening.

[jslopez93]

I meant to put a smiley face in there.

I had an excellent ride last Saturday and would just like to see how my training/numbers stack up (otherwise all I have to go with is anecdoctal evidence).

Your feedback would be greatly appreciated.

[racerfern]

@jslopez93

Of all the rides you sent, only the 3 mile calride is usable. As you can see the wind is very positive in both directions. This can be due to a couple of things, firstly did you do a proper wind calibration and secondly your wind scaling number nees to be lowered quite a bit.

By using the Check calibration feature and clicking on both "Estimated" tabs you can see the settings. Does your height and weight along with riding position match what you see? If so, you'll see in the calibration changes window that your wind scaling drops from 2.2 to .996. If these numbers seem right then send the profile to the iBike and you should be set. You can always correct your height, weight, riding position, etc. then send to ibike.

[jslopez93]

Sorry Racerfern but 3 mile calride is usable as what?

By doing a few adjustments in analyze calibration I was able to make noticeable change to be near the middle but what does that tell me (since the resulting power numbers in the 3 mile ride appear high to me).

I guess I am used to doing a cal ride, some coast downs, download to computer so that I can have it analyze it and I'm done.

Analyze calibration (and how to properly use it) is not very clear to me and right now I'm not really sure how to properly calibrate my Newton.

Apply the profiles created in both methods to my 75 mile ride produces very different results.

I'll be heading out tomorrow to do another cal ride. Some clear directions on what to do to ensure this is done right would be greatly appreciated.

thanks.

[jslopez93]

Also a note on wind scaling, seems like that 2.200 is the default number I get when I create a Quick start profile.

Is that expected?

[racerfern]

Some of your calrides were less than a tenth of a mile so those were not useable. The 3 mile calride had excellent data. So clicking both estimated tabs comes up with a new profile with your height, weight and riding position. Note, that you need to confirm some of these choices at your end. When I run Isaac at my end it defaults to my last riding position selection and last traffic selection. These may not be what you intended.

So... click both estimated tabs, confirm all the data is correct and you'll see the new wind scaling number. Send that profile to the device and accept. You should probably do one more 3 mile calride in the same place as the one you sent me but with the new profile. Then we can check calibration to confirm we have a good profile. OK?

BTW, more than likely a default wind scaling is picked based on your choice of mounting location in the Device Setup via Isaac.

[jslopez93]

Thanks RacerFern.

The shorter rides I had originally attacehd were actually coast downs not cal rides (hence the small files).

Before today's ride I downloaded 3 profiles on to newton to test:
- Profile 1 - 3 mile cal ride tweaked with Analyzed calibration
- Profile 2 - 3 mile cal ride that used download coast down/cal ride feature
- Profile 3 - Auto set up profile using newton software (but adjusted the windscaling to match profile 1)

After a tilT cal and wind ofset on each profile before heading out, I watched the power numbers in the coast down msection (of user menu) in each profile and saw that profiles 1 and 3 were consistently in the +/-10 watt range when not pedaling.

The only weird thing about profile 3 was that power numbers would go up even when I was completely stationary buit my guess is that may be beause I was shifting from 1 profile to another, mid ride.

Anyway focusing on profile 1 for the rest of the ride I noticed that it continued to stay in the +/-10 watt range even on downhills (which is where I was having issues with my ibike gen 3 in the past).

Is this a good enough test or is there some more evaluation on actual ride file tht someone can do?

[racerfern]

Coast downs have to be downloaded as a special kind of ride. I recommend you don't even bother with coastdowns.

If you switch profiles mid ride the Newton automatically starts a new ride and it will have trouble with tilt for a few minutes. If you want to switch profiles, stop, reset the ride by holding the center button and confirm. Then switch profiles and do your next ride.

Wattage of +10/-10 while coasting is just about perfect as long as you're rolling at a reasonable speed, say 15mph+

It seems you have a good profile.

[still-chasing]

Here's a report on my latest Cal Ride:

Did 3 Cal rides today back to back to back as suggested by Fernando. Early morning when there is very little wind. Rode around for maybe 1/2 a mile to acclimate the unit. Did a Tilt calibration followed by a Wind Calibration(twice) to make sure.

Started going and when I reached my cruising speed, I clicked Cal ride. I was careful to keep my pace steady. Did this 3 times.

Downloaded the 3 files as regular rides and did a "check calibration" for each file. Happy to say that each calibration is very close.

Here are the results: Cda is held at .309 and Crr is held at .0055
Aero .297 .288 .297
W. Scale .962 .933 .960
Fric 7.719 7.719 7. 719
Tilt -.5 -.5 -.5

I will discard the 2nd Cal ride and average the 1st and 3rd which are very close and use that as my profile.

[jslopez93]

Coast downs have to be downloaded as a special kind of ride. I recommend you don't even bother with coastdowns.

If you switch profiles mid ride the Newton automatically starts a new ride and it will have trouble with tilt for a few minutes. If you want to switch profiles, stop, reset the ride by holding the center button and confirm. Then switch profiles and do your next ride.

Wattage of +10/-10 while coasting is just about perfect as long as you're rolling at a reasonable speed, say 15mph+

It seems you have a good profile.

So here's my confusion, I've been doing structured workouts over the last 2 months with the Ibike gen 3, the lately switched over to the Newton.

While the coast down window on Newton still shows the +/- 10/20 watt range when not coasting (I check this several times during the ride now), the last few rides it just seems a lot easier to hit and stay above at what was previously my FTP and slightly beyond. This is most notably on the flats where previously it would take an almost herculean effort to be at FTP.

Again on today's ride it felt like I numbers were higher than with Gen 3 at same Perceived Effort. On the first 2 miles of my climb today (file attached) I was riding at at pretty good pace, a season personal best, but numbers show that I was riding average was about 60 watts higher than 2 months ago which seems excessive.

Some factors could be because of recent, very focused training block from a coach I am now working with, plus this was a recovery week (till today) but I do remain very skeptical and it would be great to feel confident about Newton numbers.

Thoughts appreciated.

[racerfern]

It's always tough to explain why things have changed and it appears you're putting out more watts.

Your personal conditioning.
Was the previous profile off slightly or is this one off slightly?
Did you do the same setup process with the Gen3 back when you got it?

I remember being a beta tester for the Gen3 years ago and cursing the fact that I switched units mid-season. So here we are again.

You could tweak your profile slightly in order to match the other unit then you continue with the same training plan and FTP, OR... you could do a new FTP test and move all your goal points up a bit. Regardless, this will be your new norm and you can continue on. I know exactly how you feel but I wouldn't fret over it. Set your numbers and soldier on. Easy for me to say isn't it.

BTW, you mention the +10/-10 while not coasting, you mean while coasting don't you? Have you turned on the CdA function? That gives you similar answers to coasting and watching the coast down screen without having to jump through hoops in the menu while you're riding.

[jslopez93]

I did mean by coasting and I do take your point to heart about taking the new norm and moving on.

I was just trying to make sure that nothing was wrong with my newton unit as I would have thought that numbers from Gen 3 to Newton would be similar.

As long as there are no flags of defective unit from my rides I can continue to see how the numbers continue to pan out.

Did not think about using CDA but will will try that next time.

Thanks!

[Velocomp]

I looked at your 48 mile ride.

Your profile and ride file both seem fine. What's puzzling is your FTP; you've got it set to 209.6W. This seems pretty low for a rider of your ability. You've got several sections, both on the hill and on the flats, where you're pulling nearly 300W for periods of several minutes. In fact, you climbed a 6% hill for over 11 minutes at 264W avg. Based on this, your FTP should be at least 240W. I'm guessing that it is closer to 260W.

One odd thing in your ride file are several watts spikes. Make sure your speed sensor/magnet is properly positioned. I edited your file and it is attached.

[racerfern]

The spikes are from going into the coastdown screen to observe wattage plus or minus while coasting. Either when you enter or exit the screen some spikes are recorded. I get rid of them by clicking on "Switch profile after the ride" and I switch to the same profile; no more spikes.

This is one of the reasons I recommend setting CdA on along with the need for less fumbling while you're on the bike.

[jslopez93]

Well on old ibike I was working with 210-220 FTP.

To give you an idea (or to add to the confusion) on 6/3 I was doing hill intervals on the same climb I did yesterday and was going all out averaging about 220 watts. Yesterday the average was around 270 watts for the same climb.

In retrospect, maybe the ibike gen 3 was calibrated low as it seems fine (watching coast down window cause I didn't know any better) on flats but would show a significant negative number on downhills.

The new numbers put me int the average rec rider category (as opposed to the are you sure this isn't your first time on the bike category of before ) and that seems realistic.

Thank you for pointing out relation between coast down as I could never figure out why some of my files had these.

[racerfern]

Your climbing numbers are spot on as confirmed by bikecalculator.com. It's not as easy to calculate wattage on flats because there are so many variables the biggest of which is wind and depending on where you're riding either other riders or cars.

However, using the the 5 miles starting at .8 miles bike calculator shows 107w and your ride shows 115w. That's really close considering the variable nature of riding on the flats. Checking other flat sections yields similar numbers.

The screen shot has Set A which is the climbing section and Set B which is the flat section I pointed out.

You might want to consider the following very slight changes.
1) Leaving your CdA the same, lower your wind scaling from .9 to .85
2) Lower your Crr to .0051 AND lower your Riding tilt to -.3. I'm inclined to think you don't push the front of the bike down -.8 when you only weigh 138lb.

These two changes are very minor but will lower your power numbers slightly and at that point you should do another FTP test. John is right, your FTP is probably higher than 210.

[jslopez93]

You might want to consider the following very slight changes.
1) Leaving your CdA the same, lower your wind scaling from .9 to .85
2) Lower your Crr to .0051 AND lower your Riding tilt to -.3. I'm inclined to think you don't push the front of the bike down -.8 when you only weigh 138lb.

These two changes are very minor but will lower your power numbers slightly and at that point you should do another FTP test. John is right, your FTP is probably higher than 210.

Are these recommendations I should also put on the profile for my other bike?

How did you come up with those specific numbers had will a tilt calibration affect the -.3 ride tilt?

[racerfern]

IIWY I would make a copy of the profile and apply these suggestions. Then send it to the iBike. You can always switch profiles later on.

Other bike? If it's the same type of bike, road bike, same basic geometry and tires then yes, absolutely. If it's different tires, geometry, style, then I would do a cal ride and establish a new profile for it.

Most of today's high tech tires (which we all tend to buy) have very low Crr. Additionally, I really don't see how your tilt calibration could be -.8 unless there's something very wobbly or loose on your bike.

Basically, I was looking for a way to slightly lower your overall wattage without creating a new monster. Even my suggestion to go from a wind scaling of .9 to .85 is almost extreme. If you think you're somewhere between the two then make a profile with .875.

Make sense?