Jet Black Victory

General Discussion
918

I take sticky to mean that there’s a bit more friction from the belt, especially before it gets worn into the groves on the pulleys and gets softer and more pliable. The softening part probably happens as the trainer (and belt) warm up.

The sweet spot for accuracy for my trainer seems to be when the trainer reports about 5-10 watts below my power meter numbers at the very beginning of a ride (first 3-4 minutes). Then as things warm and loosen, the two power numbers match much better. I wish there was a temperature compensation, but I think that just adds too much programming and probably increases the likelihood of failure or miscalibration.

As far as slippage, yeah there shouldn’t be any slipping at all. These same serpentine belt systems are used on heavy machinery (think air conditioning and power steering pumps in your car), and the tension from the retaining spring is very heavy.

ETA: Sticky might also be referring to the phantom watts as being similar to “sticky watts”, i.e., power reported even during coasting. Although, sticky watts in the Zwift context are an entirely different matter.

919

Thanks for pointing out the potential need for additional ventilation directed at the JBV for extended rides. I’ve never particularly noticed any differences between expected and actual resistance in my long rides, but it makes sense that heat would build up and have some kind of detrimental effect. I often end up doing an ‘involuntary’ spin-down calibration at the top of Climb Portal rides. LOL.

920

Hi Steve, please tell me you found a solution because I’m facing the exact same issue right now, really throws me off when I hear the frame click when I put the power down.

921

Hi everyone,

I live in Québec, Canada, and I wanted to share my experience because I’m honestly getting quite discouraged with this trainer.

I bought my JetBlack trainer in October 2024, and right from the start I noticed a low-frequency vibration or humming sound on every pedal stroke — especially around 80–90 rpm and roughly 150 watts, for example on a 4% slope in Zwift. The vibration can be felt through the pedals, it’s audible, and it even travels through the floor (I live in an apartment). My setup sits on a very thick, heavy gym mat, so it’s definitely not a flooring issue.

I contacted JetBlack Canada support, who were very responsive and professional — they sent me a replacement unit right away. The new trainer even came with the new Zwift controllers.

Unfortunately… the exact same issue persists.
Same vibration, same humming, same intensity.

Here’s what I’ve tried so far:

Updated the firmware to version 4.23;

Rode for about 10 minutes on Zwift, then performed a calibration in the JetBlack app;

Tested with two different bikes;

Tried with and without the Zwift Click cassette;

Tested with and without cycling shoes, different thru-axles, and different floor types.
→ Same result every time.

Some extra technical details:

My Ultegra 11-speed chain has less than 300 km on it;

My first trainer was among the very first units shipped to Canada;

The replacement unit came with a rubber transport support and a mainboard version 3.11 (my first unit had 3.10);

The bearings are not identical between the two units, but the vibration remains exactly the same.

The Canadian JetBlack reseller told me it was almost impossible for two units to be defective in the same way.
But honestly, this trainer is unrideable — the vibration causes numbness, and it’s impossible to ignore since it happens on every pedal stroke.

Other than that, everything else works fine — the firmware 4.23 update, the connection, calibration, etc. But the mechanical issue persists.

My next step is to go to the store where I bought it and test another unit in person to see if it also vibrates at 80–90 rpm / ~150 W.

Also, does anyone know if it’s possible to find out when a JetBlack trainer was manufactured, maybe through the serial number or some other identifier? I still have both of my units at home, and I’m trying to figure out if my “new” one might actually be from an older production batch. It seems that JetBlack recently started including the Zwift Cog v2 with two controllers in all boxes, and some older boxes might just have a simple sticker added to indicate this — but I could be wrong.

It’s very frustrating: two trainers, same issue, and still no clear answer. I’ve read this entire discussion thread, and it seems like several others are experiencing similar symptoms. Hopefully, by comparing our cases, we can figure out whether this is a batch issue, a design flaw, or something else entirely.

Thanks in advance to anyone willing to share their feedback or testing results.

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922

Thanks for sharing the photos. Interesting to see different sized bearings (6001 vs 6002) and the switch to rubber seals.

As for the vibration, in my experience this has been an issue that I’ve encountered if the flange bolt on the flywheel pulley is not properly torqued. Since your unit is new, I wouldn’t fidget with it if you plan on returning or getting a warranty replacement.

I recently had that bolt come loose after a few hundred km when I replaced my belt and inspected the bearings. During reassembly, I used loctite and torqued to spec with a torque wrench, but it still loosened slightly about a week later (thermal expansion or maybe the threads picked up some grease and didn’t hold well?). I backed the bolt back out, scrubbed it clean, rinsed it with rubbing alcohol, and then reinstalled with new loctite to resolve the issue. It’s been fine ever since (knock on wood).

I think if the flange bolt is loose, there is enough play between the pulley and shaft to clank around once per rotation. Add in the spring and harmonics and it begins to feel like pedaling over boardwalk and can sound pretty rough.

Alternatively, I recall hearing that there were some premature bearing failures due to shipping mishandling. But, that was back last January with the first few waves.

923

I’ve been riding my JetBlack for around 7 months now without major issue except for highly variable cadence at low power levels in erg mode which I addressed by adding a dedicated cadence sensor.

After reading all the comments I’m worried the trainer could fail at some point so I’m thinking of treating this as a temporary trainer until I find one without reliability issues.

924

Damn… I literally left it as long as I could before contacting them for a replacement, but on reading here it looks like they’ve still not fixed it.

925

I bought a Victory back November. My experience so far:

  • It clunked for the first minute or so of use. After this, it was fine and with no clunking or vibration. Contacted support who said the bearings haven’t been pressed in properly. Returned for repair and to get the “new upgraded bearings”. Got it back a couple of weeks ago. Still clunks for the first minute or so of riding.
  • I had issues with it reading high compared to a P2Max crank and Magene pedals (triple-recording) by about 20W. On first use I did as advised by JetBlack and did a spindown after 10 mins of riding, but it seems only 10 mins doesn’t get it up to temp. After doing a spindown after a ~1hour session, the numbers are pretty close to the P2Max/Magene, but only after a warm up of about 15 mins. The Victory starts off about 20W down. I could see how people could get 20W for free by doing a spindown before riding. My previous trainer was an Elite Direto, and I didn’t observe any extended warm up period before power numbers match my power meters.
  • WiFi connectivity has been good, except a glitch when my partner turned off our router during a ride. I couldn’t get it to reconnect and abandoned my ride (very annoyed as I was 3/4 way up the Alpe).

So I’m mainly happy so far, but the clunking worries me. The warm up period is annoying, but I’m pleased that after this period the data matches my power meters well (around 3W down on a crank based PM on average, exactly as expected). I find it much less stable than my old Direto when out of the saddle sprinting. This is perhaps exaggerated now I’m using tennis ball rocker feet, but the rocker feet give a nice feel during normal riding.

Fingers crossed for trouble free months or years ahead.

926

Well I’m back with a few updates. First, I think I’m going to stop wearing my JetBlack jersey on Zwift. I had been a big fan, now somewhat less so.

I have about 2500 km on the Victory I got back in August. For the overwhelming majority of my use, I have been elated and having a great time on Zwift with it. I had not [until very recently] heard any noises from the trainer, had zero problems with Bluetooth dropouts, and felt like the power/cadence numbers were ‘directionally correct’. Everything looked so bright.

About a month ago I got a pair of Assioma Pros, and they claim I make about 10 watts more power than the Victory reports, and I’m fine with believing there is in the neighborhood of that much power loss in drive train inefficiencies. I have trouble getting the Victory to report reasonable cadences above about 105, but I can tell I’m not physically able to supply it with reliable discernable pulses of pedal at those rpms so its not really their fault.

About a month ago, I sent email to the supportUSA email address with an inquiry about the spacer they installed between the flywheel and the Cog. Ten days or so later, without so much as acknowledgement that I asked for assistance, I resent the email. Ten days later, I resent the same email again. Its been about 5 days since and silencio. In short, I think either the spacer is too thin or the flywheel misshapen such that the Cog binds against the flywheel unless I leave the shaft cap nut really loose. The issue isn’t huge, but the lack of support is concerning.

The plot thickens. Recently, it has started to make a sound that reminds me of either a low-rpm motor boat or a classic Ford Mustang exhaust. A throaty sorta 5-10 Hz sound that arises when I put something north of 200 watts into the pedals and gets louder with additional power. Thinking more realistically, it sounds a bit like a circuit board that has come loose from its standoffs and breaks into oscillation. I took off the main cover and found the main control board was ever so slightly loose on one screw. I firmed up the screws and put the thing back together. Took a nice 20 km ride [didn’t push big watts and the sound was still there] and went to bed. Even commented on my Strava that I didn’t break anything.

But now the real problem. After that ride the evening before, I got up the next morning and neither Zwift nor the JB app receive any power or cadence. They both claim the trainer is connected, but no data. Neither is able to tell the Victory to increase resistance either. So even though I have Assiomas that could feed Zwift, any ride would be some 3rd gear ‘spin’ ride. No amount of resetting, rebooting, or re-cursing changes anything. The trainer’s blue light goes on solid once either app ‘connects’, but zero useful communication. The trainer lamp eventually goes out, presumably because it believes nobody out there wants to talk to it. Interestingly enough, spinning the flywheel doesn’t not re-light the blue light, suggesting the sensors aren’t sending anything to the control board. Among my other theories is there is indeed a bluetooth ‘session’, but something like encryption is inhibiting any real data flow in either direction. Being year-end, the potential for encryption keys expiring looms large, but bluetooth really isn’t based in that style of encryption.

But wait, there’s more. My second theory is that the sound and this lack of power/cadence problem are related and could be found inside the flywheel housing. So, I set off on taking it apart. I got the belt off considerably easier than the published approach, and found removing the pulley bolt surprisingly easy to do in spite of finding it conventionally threaded when reverse threading seems more logical to me. But now I’m up against it. I can’t figure out how to ‘gently pry’ the flywheel pulley off, so I’m using the handle end of a ratchet wrench as a means to hammer the crap out of the end of the flywheel shaft inside the pulley. [I don’t own a gear puller.] It doesn’t appear to be damaging the shaft [but its too soon to be sure], but the damn pulley has only moved about 1/4 inch (6 mm). I have nightmarish visions of what all that percussion is doing to the circuit boards. And there’s no guarantee at all that once I get the flywheel off there will be an obvious solution to the lack of sensor data problem (I’ll live with the throaty vibration noise if I have to, but that seems like it will be easier to locate once inside).

I’m not sure how to proceed. Certainly looking for a local retailer of a Wahoo Kickr is high on my list. I’m not going without a trainer for goodness knows how many weeks. I’m actually even tempted to just buy another Victory if I can have it overnighted, but I don’t know where they stand on inventory these days.

Ideally, of course, there’d be a service center model where we could get a loaner while ours is in the hands of qualified repair people. Really ideally, there’d be a support model where some human would be more readily available to help. I’d like to give them the benefit of the doubt that the company just can’t grow fast enough to keep up with the demand, because looking at the inside of the trainer demonstrates a pretty reasonable attempt to engineer a quality product. [The software sucks, but that’s always an afterthought with these new hardware companies].

Anybody that has any suggestions for getting this flywheel off, I’d be most appreciative. If you know what I should look for once I gain access, that’d certainly be welcome input too. Cheers!

927

I was wondering if the Wahoo Kickr Core V2 would solve all the issues we have been having with the Victory. I bought one in the xmas sale and my very first ride on it I got a wireless dropout - exactly the same issue I was having with the victory! To make matters worse, there is a really noticeable vibration coming from the trainer that shakes the whole bike, which I can feel through the pedals, saddle and bars, so I have opened a ticket with Wahoo to see how they are going to sort this out. I’m assuming the flywheel isn’t balanced properly as the vibration is very noticeable when coasting from high watts. It seems like none of these “cheaper” trainers are without problems/compromises.

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929

For people who land in this thread trying to dis-assemble their Victory, I wanted to share the technique I used to remove the belt, which differs from the suggestion I often saw of somewhat brute-force working the belt off the side of the pulley. I found that, in spite of the casing being plastic, it can withstand the force of a clamp that pulls on the rotating plate that the spring attaches to, thereby reducing the force applied to the belt by the idler. I used a quick clamp, but a C-clamp would probably do it as well. The belt comes off easily. and without damage/distortion once the idler pressure is removed. I tried to favor the clamp pressing on the plastic near where there is an internal plastic gusset (or does that just help keep the belt dust off the control board?). A gentle approach is probably warranted - a savage impatient use of a clamp will invariably break the plastic housing.

930

Another update. I destroyed my Victory trying to get it apart, beginning with not owning a pulley puller to remove the flywheel pulley. Turns out, the rod I was using to hammer on the flywheel shaft inside that pulley was actually catching (and significantly deforming) the key and to a mild extent mushrooming the end of the shaft. It also deformed part of the first thread inside the flywheel shaft. I eventually got the flywheel shaft out, and I could machine the shaft back to useable, but I decided these actions weren’t worth the effort given the likelihood that the speed sensor was the actual thing that failed in the first place. If I could run out to W-Mart and grab another speed sensor, I might think differently.

Inside the flywheel housing was similarly good-looking to the naked eye, with seemingly quality materials and professional workmanship. Nothing about these trainers screams cheap-o plastic crap. Nothing was found loose to explain the throaty 5 Hz sound I thought might be related. I think the sensor itself failed and the sound will forever remain a mystery.

Because I’m loyal, naive and perhaps dense, I ordered another Victory and begged them to expedite it. Rest assured I won’t be buying a third one if the new one craps out in 5 months. With additional naiveness, maybe they’ll fix this first one under warranty, but I’m not holding my breath and I can’t wait around that long without my daily Zwift ‘fix’. At least I’ll have some spare parts for the new one. :smiley:

931

Mine is also started doing this immediately after being returned from JetBlack where the trainer’s bearings were replaced. In my email chain, the UK service person said that they had another coming in with this exact problem.

932

My JetBlack has just stopped registering power and cadence. I presume cadence is derived from the power so presumably the power sensor is kaput.

Mine has been used for a total of four hours and 150km!

Anyone know if there’s a master reset procedure? Worth a try.

933

Having taken the whole thing apart, I don’t see anything other than the speed sensor next to the flywheel as far as inputs go. There are electromagnets for creating resistance, but it appears both power and cadence are derived by mathematics from the speed sensor’s detection of the transitions between the white and black sectors of the sticker on the flywheel. I already knew cadence was somehow derived from what I’ll call ‘pulses’ of torque it detects, but I didn’t know torque was somehow derived from angular acceleration. Other than cycling power to the trainer, I haven’t seen/heard of any other ‘reset’ procedure. I unplugged the speed sensor from the main control board and plugged it back in as part of a ‘grasping at straws’ idea meant to dislodge any theoretical corrosion in the contacts, but to no avail. I didn’t try swabbing the speed sensor itself with alcohol as another desperate experiment, but I have abandoned all hope now.

934

This is not the first time I’ve encountered reports of “speed sensor” failures with the Victory. What do we suspect is causing them to fail in relatively short periods of time? Anything we can do?

Grime: They don’t appear to be exposed to belt dust or grease [or sweat]. Over several years, of course there would be some accumulation of household dust that might need periodic cleaning after disassembly, but that almost can’t be causing premature failures like this. When I took mine apart, the black/white surface they bounce light off looked pristine after 2500km and the rest of the interior on that side totally dust-free.

Vibration: The board the sensors live on is screwed to the housing without any obvious dampening, but it wouldn’t surprise me to learn that any such dampening would interfere with the math that is deriving power and cadence from the sensor inputs. I never had any sense the housing / flywheel side were vibrating (from sensations through the bike or from sounds), but I never had my hand on the flywheel housing while someone else pedalled. Examining the solder joints on the sensor board under a magnifying glass didn’t reveal anything interesting. [I didn’t see anything interesting on the main control board’s circuitry either.]

Heat: The more I think about it, the more likely this seems to my amateur way of thinking. The sensors live fairly close to the flywheel shaft bearing, which presumably (but I have no knowledge) heats up the air nearby. There is an impeller on the flywheel to move air inside the housing, so somebody thought something needed to happen. Notice there are no vent holes in that housing, and that hot air egress and cool air ingress would have to be through the gap between the flywheel and the housing. Maybe that’s enough? Again, I’ve never monitored the heat coming out of the top of that gap while the trainer was warmed up and ‘underway’. I did hear of someone that has a fan directed right at the trainer, but I forget what they thought needed cooling down. I’m inclined to guess there needs to be vent ‘holes’ (of some shape) on the bottom of the housing. I wouldn’t propose holes on top for sweat, cleaning liquids, and household dust ingress reasons - let the hot air escape through the flywheel gap. It would be interesting to install a thermocouple inside that housing near the sensors. It might be necessary to install a computer “muffin” fan somewhere [underneath?]. It might be … that they need to procure more expensive sensors with higher tolerance to heat [and vibration].

I hope somebody at JB is trying to make this problem go away - not just for customers’ sakes, but to reduce their cost of warranty repairs.

935

Man, sorry I missed your question about disassembly. I wrote a detailed guide and it’s buried somewhere in this thread. Banging on the flywheel shaft is not ideal because of the potential for deformation of the shaft, key, pulley, and most delicate angular bearing in the flywheel side. Threading the pulley bolt in a few threads into the shaft and tapping with a socket and dead blow would be about as rough as I’d go before reaching for a gear puller.

From what I’ve gathered and recreated on my end, the vibration/roar/clunking noises are linked to mechanical slop or damage in the angular bearing. Either the bearing is indented and trashed from impact (shipping) or it’s not preloaded correctly because the flywheel pulley bolt has backed out or was over torqued. A torque wrench and loctite have fixed my temporary bearing noise twice now. You may be able to fix the end of the shaft with some light honing (emory cloth and fine wet sanding).

I’m dubious of any electrical issues since the layout is so simple. A while back, I found the part no for the surface mount optical sensor, and you could reflow a new one on if you really think that is the issue, but again, I don’t see that being a problem.

More than likely, the connectivity issues are related to the ESP chip. These are used in all sorts of “smart” or IoT devices, and while powerful for their cost, they sometimes don’t play well over Wifi or BT, and troubleshooting is pretty rough. I had some issues with Wifi dropouts when the trainer was connected to my dual band mesh network. I don’t know whether other devices on my network were conflicting IP addresses or if the ESP was struggling with the dual band or mesh. I’ve since moved it to a dedicated, 2.4 Ghz only IoT subnetwork and turned off meshing. That has resolved most issues.

If you’re on BT, I don’t know where to start exactly, but refreshing all BT connections and moving your BT receiver closer to the trainer can help. If you’ve used the JB app, you might want to reset your phone to make sure there are not multiple simultaneous BT connections. Same for any head unit that you’ve used for dual recording.

If you want to know for sure whether it’s a sensor or connection issue, you could always try ANT+. It’s pretty rock solid but just doesn’t do virtual shifting unless I’m mistaken.

936

Looked again, and I think the sensor is a QRE1113GR.

937

The support people think its the speed sensor as well, and note this is a problem signature they have seen and repaired before. I have BT; it has reliably connected every time for months, and the iPad ‘catching’ those signals is about one meter from the trainer and I’ve eliminated every possible source of BT interference. I don’t have an ANT+ dongle for my iPad and am not eager to buy one just to see. I saw your instructions re disassembly, and they were great except the part ‘gently remove the pulley’, which didn’t want to happen for me. I knew banging on the shaft was risky, but [was impatient and] didn’t see another way. I’ll have another new trainer by the weekend according to UPS.

938

Thanks for the sensor model. Cannot imagine what Superman vision revealed that to you. I may go down that rabbit hole on this trainer after I’m back in business on my new trainer.