Direto XR problems with ERG mode

[guiperpt]

Curious if we could maybe reach out to dcrainmaker and/or gplama to do a short re-test of the trainer with the new firmware update, version 73, the version every one of us can actually install to see if it performs as good as the version they were able to test.
Also a bit frustrating that we are not getting any reply of an admin on this thread

Definitely not all of us, I'm still on Version 67, no matter the country I choose. Elite admins, when is version 73 available to everybody?

[JohandeWit]

Hi all,

I'm new to this forum and it took a while to register. I read this thread with a lot of attention because I also purchased a Direto XR 3 week ago, as an upgrade of my Elite Turbo Muin b+ which, i liked very much, but had no ERG.

I was able to upgrade my XR directly to firmware 073, i guess it was available just some hours
Anyway I can't judge the experience of firmware 067 but I too am disappointed by the performance of the ERG mode. I did expect a lot more of it after the review of both gplama and dcrainmaker.
Don't get me wrong, I like te trainer. It is sturdy and quit, and the feel in non-ERG mode is ok.

But I do a lot of interval training in Zwift and that's why I upgraded my trainer to the XR.
The biggest problem I see at present is perse the deviation in the power. It seems I get comparable results as posted by enesto a few replies back. I do use an external cadence sensor and have power smoothing set to 2. I also checked my calibration which is just 1 point of compared to the sticker, so it is just fine.

My biggest issue is the response of the trainer to a step in power. It takes quite a long time for the trainer to respond to such a change, around 20 seconds in most cases. This means that a training with smaller intervals for 30s (for example over/under interval) are impossible to perform in this way. By the time the trainer responds, the interval is over. I do notice that respons to a step up in power (keeping your cadence as smooth as possible) is reached earlier, but respons to a step down is terrible.
I can get cleaner intervals using my Turbo Muin and shifting gears myself. So this means when I enter a training with short intervals I end up switching off ERG mode. That's not why I bought this high-end trainer.

So i really hope that Elite listens to this thread. This is their TOP-OF-THE-RANGE trainer right? Must be possible to improve this!

I also search this forum for a long time and noticed some past threads where previous Direto trainers had the same issues. I also read in a thread that Elite customer service sometimes reach out to their clients with a tool that creates "a new profile". Would that be the "trainer diagnostics" button in the Elite app?
I also read that some customer than got the receive a file that they can upload to the trainer with the Ugrado app that seems to influences the behavior of the trainer. Does anyone here know about that? Perhaps that an Elite responsible cares to react on this?

[JohandeWit]

Curious if we could maybe reach out to dcrainmaker and/or gplama to do a short re-test of the trainer with the new firmware update, version 73, the version every one of us can actually install to see if it performs as good as the version they were able to test.
Also a bit frustrating that we are not getting any reply of an admin on this thread

Good suggestion! Let's ask them.

[enesto]

Hi all.
I tried to do some intervals with no erg and it seems to me easier to maintain a steady power level... jhankey I'm really keen to know your test with TT bike on flat...

For erg mode I get the best only setting smooth at 6 and by keeping a cadence of 80/85....

For the workouts where zwift is asking you to raise cadence to 100 or to lower it and selecting a longer gear combination, erg is unusable.

It seems that you need a sort of grace period where the sw can adapt the resistance to your cadence and after, when power level changes, it starts readapting...

So for medium long interval, I can find a pace with +/- 8, 10w, when intervals get shorter, mess begins...

I'm sure elite can improve this...

A deeper look by Shane and DC can be very useful I think... How can we do to ask them to help us?

Bye!
E.

[jhankey]

Enesto, not had channce to do my TT thing yet, will look at it tomorrow.
Take a look at https://www.smartbiketrainers.com/diret ... view-12193
In their breakdown they get what we are seeing when pushing a 53/13 at 78 rpm. Even 53/17 is better than we get.
When you look at the third trace in their tests it is what we get in say a 34 /20 gear.
Also worth noting, in the two relative good erg 10 min tests, I would argue that the guys cadence is not as good as yours!!

I will use the TT bike for reference tomorrow and I should now be able to post some numbers (excel) here.

I am also tempted to try a very small gear, 34/32 , at low cadence to see if that helps the issue.
Cant help but think something has gone wrong here on some of their units. Just not getting anything like DCR's ,Lama's or smartbiketrainers performance figures here.

I still, really want Elite to work this out, I really like the feel of the trainer.

John H

[JohandeWit]

jhankey, enesto,

i looked at the link you provided on smartbiketrainers. He shows some training and gets acceptable results. He mentions and shows that in ERG mode after a power change (from recovery to above ftp) the trainer settles in a few seconds. Even in small intervals.

That's not what I see at all! As mentioned in my post before it's more like 10s of seconds, and shorter intervals are hardly doable in this way.
I did notice he uses firmware 067 (he shows his update app), he does not mention the power smooth factor. But I guess he didn't change it out of the box.

So this got me thinking. I do my interval training using Zwift. I think he uses Trainerroad. Could it be that the application that one uses to control the trainer has some effect? (I can imagine that eg Zwift also applies some filtering of the power/cadence data coming from a trainer)

@enesto, I would like to analyse a bit more using Xcel as well. How do you create you xcel files? Which app did you use to perform your intervals?

regards,
Johan

[guiperpt]

One more possible clue, smartbiketrainers has HW Revision 003, as per screenshot of his upgrado app. Which HW revision you guys have? I have HW Revision 001 on my Direto XR bought 3 weeks ago.

[BelgianFlandrien]

Hmm, good catch, im also on HW version 1. The problem being hardware related would be very bad news, but both DC and Lama are on hardware version 1 (see screenshots), so our units should be able to show the same, good, results.

[jhankey]

Direto TT Test.xlsx

Tempus Fugit 175w ERG

(232.93 KiB) Downloaded 608 times

Enesto/ All

Please see attached excel file.
Taken from zwift flat course on a TT bike in erg mode.
10 min ramp up to 175w then 15 mins at 175w.
Cadence 81 with some gear changes, cadence 90+ for the last part.

Last part of graph was with ERG off.

I have offset the actual data so that all the fields appear in the same range....
I have added a watts smoothed line which is a 5 sample average of the watts. It is 'advanced ' in time as it takes the forward 5 samples.
There seems to be an inherent oscillation on cadence. Also for a rising ramp up, my heart rate do not increase linearly. And a constant work rate my heart rate was fluctuating up and down by plus/minus 2 beats. This is wierd for me, as I generally get a really even heart rate with a slight increase over time due to temperature.

I will repeat this on my tacx vortex at some point.

The power smoothing numbers in the table would be acceptable. I also need to see if the cadence oscillation is related to cadence --- rpm is by definition an average over a minute, as are speed measurements, km per hour. These devices measure over a short term say 5 secs then multiply by 12 to show R/minute. I suspect the direto measures much quicker than this, may be several times a second. If this is the case it could be measuring cadence/speed at different parts of the stroke. ( This gets a bit technical ... but stay with me) The direto may have a sampling rate of say 6 times a second, and pick up 6 slightly different rpms / speeds within that time. If cadence is some function of this sampling rate, the samples are taken at the same part of each stroke on each rotation, but if there is a slight increase in cadence so that the cadence and sampling rate are not synchronised the samples would be be taken at different part of each rotation. --- If direto is using a short sampling time for a really reactive ride experience it would need to sample at around 8 samples per revolution, at 120 rpm, that's 16 samples per second. if it's quicker than that it should have no issues. If its slower than that the data would be prone to 'aliasing'. ( 8 samples per second is required assuming 2 downward fast and 2 over the top slow pedal movements per revolution. Each of those have to be sampled twice per revolution minimum)

Sorry, that's a bit heavy... but I think Enesto will know what I am alluding to here.

[jhankey]

Enesto, I am tempted to carry out some more steady state cadence drills at different cadences for the same gear.
I could then take the data sets and run an FFT on them to look at what fundamentals are in the data sets
Starting to feel that I am doing Elite's work for them!!!