Help diagnosing knocking sound

  • Can anyone listen to this and help me diagnose the possible causes of the knocking sound, possibly confirming my fear? The sound almost never occurs when I turn left and is most pronounced when I turn right. In this video, I am circling to the right the whole time.

    Thanks in advance.

  • Omg! You are soooo fucked man...your rig is totaled....

    I read on the fb pages quite a few people have had this same issue. Just tighten the bolts that hold the motor and wheel in place. The axel and side bolts...should clear it up. At least that’s what they said and the people that had the same problem said it fixed the issue...

  • I do wish it was that, I have checked and the axle is on tight. I have had those bolts come loose before, after my first tire change. Just to be sure, I loosened and re-tightened them, but the knocking is still around. Thank you for the idea.

  • @biell you checked the axle bolts that are accessible through the rails but for fun, did you check the silver bolts that are hidden?

    Very low likelihood they are loose but worth the 15 min to find out.

    Could be bearing related also but can't tell from the video. Try the simple stuff first... have you seen the bearing replacement videos? It's not that bad if it's just the bearings but if the aluminum axle is worn from bad bearings, then you need a new motor.

  • @skyman88 Thanks, I did take everything apart that I would when changing the tire and check the tightness on all the accessible components, including those silver screws and the little black phillips head screws. I didn't want to open the hub, controller box, or battery box unless someone had an idea of a component in one of them which might be making the noise.

    It has been my fear that it is the bearings at fault. I ordered the new Burris ceramic hybrid bearings just in case. I have a friend at work who's son races go-carts (the serious kind of go-cart racing), and he has changed bearings before many times. If I can't find another solution, I plan to watch the Sean Nelson video a few more times and ask his help to change the bearings. If it is the bearings, I am hoping it is the bearing making the noise and not the magnets touching, as Sean did find in that video.

    I did more testing, the noise seems not to happen as much at first, when the OW is cold, and occurs more after it warms up. That is something which would lend itself to a failed bearing. The OW has 2,400 miles on it, so a failed factory bearing isn't outside the realm of reason.

  • @biell very true. Sean's video is the best I've seen out there.

    I started a bearing replacement for a local person but it turned out it was in fact the axle that was worn. It looked like it had been mis-assembled or aligned at some point in order to cause the wear I was seeing. Aluminum is great for heat transfer but the axles should really have a steel bushing over them for bearing contact. Could be done with a thermal interference relatively easily... but hard to do after the fact when things aren't round any more.

  • @biell 2400 miles on factory bearings? I thought I heard in a video that it’s probably a good idea to at least check them and possible replace every 1,000-1,500 miles. I hope that’s all that’s wrong and you get those ceramic hybrids in. Let us know how they work out.

  • The bearings and the bearing pull kit arrived today. I couldn't wait to get help, so I installed them myself.

    The new bearings are installed and feel like floating on air. So far, no knocking sound, so that must have been it. The best way to describe the sound is that it was like to sides of a snap knocking into each other; in fact, that is what I thought it was at first. There was definitely some noticeable contact on the magnets lining the hub.

    Hopefully I have the bearings in perfectly and they last for a while. I ride about 2K miles per year, so maybe I will have to make changing the bearings part of yearly maintenance. I don't look forward to doing this again. The bearings attached to the hub went in really easily, the bearings on the plate kept wanting to skew.

    The O ring on the plate side was completely missing, I used the teflon tape trick to make a new one. The other O ring looked in good shape.

    The Burris bearings are expensive, at $64 for the pair, but they do feel great. I am hoping they give me some extra range back. I had figured that the loss in range was due to the over 500 battery cycles I had put it through, but maybe it was a combination of factors. The old bearings do not spin on their own, and it takes some force to get them to move at all. That being said, apparently 2,400 miles is a good run. The bearings which were in the OneWheel were NTN 6907LU, in case anyone wants to compare with what came with theirs.

  • @biell said in Help diagnosing knocking sound:

    NTN 6907LU

    That's awesome to hear! Glad it worked out so quickly. About the bearings and price... $64 is not too bad at all. The replacement ones I was looking at are ~$100 total.

    How did your axle look?

  • @skyman88 the axle looked great, apart from the one missing O ring. No scratches, rubbing, or other wear marks to be found.

    I don't drop from higher than about a foot. At 43, I don't heal as fast as I used to. So, my general rule of thumb is to only do things which I feel like I will land 99 times out of 100. That being said, I ride off-road a lot, and there are a lot of very rocky, bumpy trails around here. I am not sure how much that all contributes to axle wear and tear.

    Delaware is going to be covered in slush for the next few days, so it will be a few days before I can put it through a good series of tests.

    That is good to hear about the price. Burris usually provides a good product for a good price. I realized after I submitted my post that I spent the same amount on my tire, and the bearing are just as important as the tire.

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  • @biell Could you please provide a link to the bearings you bought? Would be much appreciated.

  • @Khayman I bought the Burris Onewheel Ceramic Hybrid Bearing.

    Since the install I have had no issues. It is hard to tell with the fluctuating temperatures, but I believe I have a small amount of extra range. Also, the OneWheel feels like it wants to go faster now, when I am riding it. I don't know how to explain it other than that. It probably has to do with the new bearings being so smooth, there is less resistance.

  • @biell awsome! Thanks.
    Was it hard to install?

  • @Khayman I would recommend watching this video multiple times, I probably watched it 4 times before the change, then actually watched it during my change, pausing when I was going too slow to keep up. Don't try to keep up, just pause it.

    Along with the bearings, I also bought a bearing pull kit, one with 1mm increments so I was guaranteed to have the exact right sizes.

    If changing your bearings is not an emergency, then look hard to find someone with a proper press. I cannot stress enough how important this is. I was unwilling to ride my OneWheel because of the sound; I didn't know if I was destroying it from the inside. In my life, this constituted an emergency, and I made due with the bearing pull kit and what I had around my house. All of my stress for the change came when setting the bearings. My hope is to never go through that again and change the bearings before I start experiencing any issues.

    If you have changed the tire before (I have done so twice now) it is only incrementally harder to add the additional work to disassemble and reassemble the motor. The really "hard" part is probably less hard, and more nerve racking if you don't have the skill. As I described earlier, it is setting the new bearings in place. After that, the next hardest part for me was getting the silver screws off of the axle, my allen wrench was bending a lot, because they were so tight. I was becoming afraid it would break and was just about to go get my safety goggles and gloves when it finally budged.

    Watch the video, and, if possible, find someone who has changed bearing before to help you. Then, it isn't so bad.

  • @biell thank you so much for the explanation, I don't have any problems yet but I feel that it's soon time.
    Maybe I can get one more summer from it and change tire and bearings when winter is coming again.

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