Jet Black Victory

General Discussion
203

Seems like the flywheel pulley bolt is not a problem in regards to vibration. I noticed mine was also off center, so I did some inspecting. Turn out that the flywheel shaft is grooved for a key that aligns with the pulley, and the threading is slightly off center as to give maximum material thickness from the radius of the hole. In other words, the pulley is already centered on the shaft, and that flange bolt is just there to keep everything in place.

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I measured the offset with a micrometer, and itā€™s just about a tenth of a mm opposite of the groove.

I found something else interesting, but Iā€™ll post in a bit when I have some time to sit down at my computer and type.

2 Likes
204

No luck for me with the email address support@jetblackcycling.com either. No replies, not even an automatic "We got your mailā€™.

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Okay, a deeper dive inside the JB Victory.

I finally pulled the cover to check and see if my flange bolt was off center as suggested by A Pukeko. Sure enough it was. I also noticed that my belt was riding at the very edge of the flywheel pulley into a pseudo ā€œgrooveā€, actually beyond what I imagine are the six grooves to mate with the belt. I also noted a bit of wear in that last, outer ā€œgrooveā€.

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So, I pushed the belt back towards the flywheel shaft while slowly spinning the drive wheel to put it back into position.

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Unfortunately, as soon as I started turning the drive wheel clockwise, the belt would jump back into the outer ā€œgrooveā€. So, I went ahead and pulled the belt off to check runout on the flywheel and see if the off center pulley flange bolt was causing some wobbling that might be bumping the belt outwards. I am getting about 2-3 thousandths of an inch (~0.05 mm) which is fine by my standards.

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I went ahead and unbolted the flywheel pulley (10mm flange bolt) and pulled the flywheel assembly out. Everything looks good there. I inspected the optical target and coils, and didnā€™t see anything out of sort. I also didnā€™t see or feel anything majorly wrong with the flywheel bearings. The construction and design quality seem quite good actually.

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Also, as I noted previously, the pulley flange bolt hole is strategically positioned slightly off center of the flywheel shaft to give more clearance for the key groove needed to lock the shaft and pulley together.

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But, check out the premature wear on that outer ā€œgrooveā€. Iā€™ve got about 600km so far on my trainer.

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That didnā€™t inspire too much confidence for belt longevity, so I went ahead and shimmed the pulley with a thin 15mm ID washer during reassembly. That has kept the belt in the 6 inner grooves, and Iā€™m happy to report smooth riding after about an hour of testing.

But, the power accuracy problem is still an elusive issue. At this point Iā€™m convinced itā€™s a software/firmware issue, not a hardware issue. I suspect aliasing or perhaps the ā€œIN REAL LIFE RIDE DYNAMIC (IRLRD) ā€“ responsive momentum to simulate riding outdoors.ā€ Is the IRLRD changing resistance in response to cadence to simulate the pulsing feeling when riding outdoors? If so, there might be too much latency at higher cadences.

Itā€™s a bit beyond my paygrade at this point, so Iā€™ll stick with my power meter for power and cadence till this gets sorted out.

9 Likes
206

Receiving mine today. Afraid to take it out of the box after reading this thread :scream: Well done guys :expressionless:

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208

Or millions canā€™t be bothered to post on this forum about their issues. Probably somewhere in between though. At least JB is well aware of the software issues and trying to address them.

209

You are off by a few orders of magnitude. JB only shipped less than 2,000 of these devices to paying customers so far.

Thatā€™s a pretty bad ratio given how many of them are reporting HW issues in this thread alone!

210

Awesome work! Can you post a picture that shows that additional part?

Also would be interesting to see if folks that donā€™t have vibration issues, already have this part installed from the factory. Or in other words: For us that do have vibration issues, the factory assembled the trainers incorrectly missing a part.

211

Iā€™m not sure where I read that, but if 2,000 is correct, than youā€™re right. thatā€™s pretty bad.

212

Just curious because a friend is waiting for his. I count 16 people in this thread with significant problems, another 3 with ā€˜gotta get used to itā€™ or ā€˜occasional wifi dropouts but doesnā€™t seem to be stopping themā€™ issues.

So thatā€™s less than 1% of the 2000 units. No way to know of course what percentage of people with bad units are posting here. Iā€™m not overly concerned for my friendā€™s incoming unit based on this, but Iā€™d be concerned with those numbers if I was JB.

213

I get mine tomorrow, and ill be sure to let everyone know If I have problems as well.

1 Like
214

Not going to look at the vibration tonight, but I will do a short ride with a calibration in the middle to see how it compares to my crank PM after warming up.

Itā€™s extremely cold here, so I might need to do longer.

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I assume JB is back in the office and Iā€™m aware that they do read these forums, so lets hope they can address a lot of these issues.

216

After reading your posting, I opened up my device again. I was hopeful that removing the vibration could be a quick and easy fix.

But in my case the belt was correctly within the expected grooves and there was no excessive wear on the outer groove. All looked fine.

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But then I had another look at the other non-grooved cog while spinning the belt and noticed that the belt is not only very close to the edge of that cog, but also moves along different positions that cog while pedaling. (Basically left and right if you look from the top while facing towards the front of the bike).

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Here is a video on Youtube that shows it much better:

https:// youtu. be / reoTw_eflWY

The vibration that I can feel while pedaling by hand do match when the belt starts moving left and right.

At the end of the video I also move the belt drive backwards. You can see that the belt stays in place nicely. Thatā€™s because while rotating the belt backwards, it hits the grooved cog first, which then directs it onto the non-grooved cog perfectly.

Did Jetblack design this belt drive backwards?

My only guess to whatā€™s causing the belt to move sideways that excessively on the non-grooved cog is that the large wheel of the belt drive is slightly bent or not attached balanced. I have no idea why thatā€™s the case.

So Iā€™m back to square one: Iā€™m pretty sure that the vibrations are related to that belt moving behavior, but I donā€™t see an easy fix for it.

3 Likes
217

Jetblack only sells in AU, US, UK, EU, CA and NZ.
So far they have sold and shipped very limited ā€œroundsā€ of pre-orders in some of these markets. Each round is a container load, which is either a small container at 250 trainer or a large container at 500 trainer.

From what I can piece together the numbers shipped so far are:
AU: 250 (JB themselves posted that number when they explained why the Aussies got bottles as a gift and the rest got towels.)
US: 500 (the second round of 500 is being shipped right now, so some might have already gotten it. You can look up these numbers through public customs records very easily for the US).
UK: 250
EU: 500 (the second round of 500 could be shipping soon).
CA: 250
NZ: None

That makes between 1,750 and 2,250 units that have been shipped so far. These are estimates, based on public records and what JB has been posting themselves. I donā€™t think that the actual number of trainers they have shipped is more then 500 of that.

218

If you scroll through this thread you see that some folks have received feedback from Jetblack that they are out on summer holidays until next Monday, Jan 6th.
I havenā€™t received any response from Jetblack after contacting their support, not even an automatic OOO reply or an e-mail confirming that they got my ticket.

219

Next Monday is Jan, 6th

220

TY. Fixed it.

221

The latest reply I got from JB is that a technician will get in touch with me on the 7th. Really, really hoping a new firmware update will sort out the accuracy issue for me (and the rest of us) and the connection problems as well.

222

Thereā€™s a comment on Reddit that new firmware is imminent from jet-black.
I think the engineer(s) are back next week. Iā€™ve still been getting contact on my open ticket.

223

I opened mine up and saw the same as you. The grooved cog was OK but the non grooved had the belt move around a bit.