Adjusting By 10%

Today has been a crazy day, filled with constant computer problems from the very start.

Most of my problems today have been related to connectivity. Whether it’s one computer communicating with another, or, in the case of cycling, getting my turbo pedals and computer to work in sync. This isn’t a new issue by any means—I’ve written a post recently that explains the problem in more detail—but maybe it was because of the frustrating morning I had. Today, it really got under my skin.

The gist of the problem is that the numbers I see on screen in MyWhoosh don’t match the numbers I’m producing at the pedals. I’ve come to realise that it’s not the numbers themselves that bother me, but the fact that I can’t do effective workouts in MyWhoosh because of this misalignment. The workouts displayed on screen don’t reflect what I’m actually doing on the bike.

On today’s ride, I spent the first half doing a workout, but once again, I encountered the same problem. The targets I was supposed to hit were consistently off, with me being 10 to 20 watts above the target power at the pedals. I found myself thinking, “I’m not sure I’ll be able to complete this workout effectively,” which was incredibly frustrating, especially after the morning I’d already had.

So, perhaps to the detriment of the ride, I started meddling. I tried all sorts of things to get the numbers to align. I began with the simple steps, like disconnecting the turbo from MyWhoosh and reconnecting it, testing the different options. For example, I tried connecting the NEO to MyWhoosh versus connecting the pedals directly. I knew this wouldn’t make much of a difference, so I’m not really sure why I started there.

After this, things got a bit more serious because I thought the issue might be with ANT+. So, I disconnected the ANT+ dongle and connected only the Bluetooth dongle. I then moved the Bluetooth dongle from being plugged into the PC base unit to the extension cable, which is where the ANT+ USB dongle usually goes. However, this actually made things worse. The trainer stopped registering any power or cadence entirely, so that was a complete failure. Strangely, it did detect the trainer, but no numbers were coming through from it.

After that, I tried the MyWhoosh Link app, which is somewhat similar to the Zwift Companion app. It allows you to relay your hardware connection through your phone, though I’m not entirely sure how it works. This looked really promising because, unlike the PC, which often struggled to even detect the Bluetooth devices (unless I restarted the computer, which I ended up doing four times during this ride), I could actually see all my devices—the cadence, power, and the controllable aspect of the NEO—inside the MyWhoosh app. But, once again, none of them were registering any numbers.

I searched the internet and found that other people were experiencing the same issue. They suggested things like restarting the computer or connecting to the app first before starting MyWhoosh, but none of those solutions worked for me.

One thing that struck me while I was checking the settings on my Garmin Edge 530 head unit was that the crank length was set to 172.5 millimetres, which I believe is the default when you first turn it on. I remembered that when I swapped from my old pedals to the Shimano 105 setup, the crank length had changed. So, I got off the bike, checked the crank length on the pedals, and saw it was 170 mm.

I made the change in the Garmin settings, feeling hopeful that this adjustment would make a difference. Unfortunately, even after making the change, the numbers were still off by about 8 to 10 percent.

After this, I went looking for the Tacx Utility app, which is now just the Tacx Training app. These things evolve, and I hadn’t been paying much attention, but I knew that was the app used to update the NEO firmware. I went in, hoping I could perhaps make some adjustments related to the crank length and that it might have an impact. But, of course, that’s not how the NEO works at all. It’s self-calibrating and doesn’t factor in crank length due to the direct drive nature of the trainer.

I understand why it works that way, but it was still frustrating.

Finally, I turned to the only other app I had left: the Assioma Pedals app. I opened it up and confirmed that the crank length was indeed set to 170 mm. I’m not sure if that setting had been updated automatically via the Garmin, or if I had set it manually in the app earlier. However, one thing I noticed in the app was the option to adjust the power balance, so I decided to try that.

In my previous post, I mentioned that the power reported by the pedals was about 8.5% higher than what was reported by the turbo trainer. So, I reduced the power by 10% in the app. I picked 10% because it’s a nice round number, and I wanted to see if making such a large adjustment would have a noticeable effect.

It was hard to tell if it made any real difference, to be honest. By this point, I had been on the bike for about an hour and 15 minutes—well, off and on the bike, really—and I needed to get back to work, so I couldn’t continue testing further.