Vibration / Rattle (New Bike)

AphoticSketch

Hey all,

I have a brand new CUBE Stereo 140 HPC Race that has a strong vibration that I can feel through the seat and I can hear it in the form of a metallic sound. Sounds like a thin piece of metal vibrating back and forth. If you can imagine how a school bell from really far away sounds, it is very similar. It only tends to happen when I'm near the top end of speed, but the vibration can be quite strong. It sounds like it is coming from the back of the bike, but I can't figure out exactly where. The sound could well be a symptom of another issue, as the sound and the vibration don't seem to fit each other.

I've taken the bike into a shop and had the first service where he checked the torque all over. There was a problem with the threads on the piece of metal that slots into the frame and rear thru axle screws into so I had to get that replaced. He also bled the brakes as one of the levers was really loose and the barrel adjuster was all the way to the end so couldn't be adjusted. It doesn't seem like Tredz did a very good job putting it together.

Any one got any ideas or had a similar problem?

robertpb

Spoke tension, cassette loose or poorly installed, dry, square or loose bearings.

AphoticSketch

Thanks Robert.

I will try and check those things myself and will likely take it back in to a different shop and see if they can find the problem.

steve_sordy

It is under warranty. The shop you bought it from should fix this.

Going back to 2012, the only time I had vibration on my bike was when the rear brake was applied. The vibration felt as though the bike was going to disintegrate and the noise was like a car horn under the saddle. EVERYTHING that ANYONE could think of was tried to fix this, all without success. I even put a different complete rear brake system on to the bike.

In the end I dismantled the bike and sold all the components. Never did find out what caused it.

AphoticSketch

steve_sordy wrote:

It is under warranty. The shop you bought it from should fix this.

Going back to 2012, the only time I had vibration on my bike was when the rear brake was applied. The vibration felt as though the bike was going to disintegrate and the noise was like a car horn under the saddle. EVERYTHING that ANYONE could think of was tried to fix this, all without success. I even put a different complete rear brake system on to the bike.

In the end I dismantled the bike and sold all the components. Never did find out what caused it.

Good shout. I've just emailed the shop.

It's sad really. It came in such bad condition. Not what I expect after spending £2.5k.

billycool

Don't accept excuses or try to sort it yourself.

Take it back and ask them to rectify it.

AphoticSketch

So, quick update.

I flipped the bike over and got the wheel rolling and think I may have identified the problem, or one of them at least.

My rear disc rotor appears to be oscillating when the hub clicks. So vibration from the hub appears to be causing the rotor to ring like a bell. I noticed the rotor was close to one of the pads so I've recentered it. Could the rotor vibration between the pads be causing the bigger vibration do you think? I guess I need to ride it again and see if the larger vibration has changed at all.

I know it's the rotor because the ringing stops when I put my finger on it, much like a tuning fork.

I've not had this problem on other bikes, so what could be causing it? I checked the bolts on the rotor and they are all proper tight.

In all honesty I don't mind it making a sound, but I don't want my bike feeling like I have ABS engaged every time I reach top speed.

AphoticSketch

https://youtu.be/6ZayMMqsI6E

Here's a video of what I'm describing. Please ignore my dogs daily gift.

Lagrange

Perhaps some copper slip grease on the disk bolts and get some low temp grease on the pawls inside the hub. (low temp because it can freeze in winter and stop the pawls and you die). (happened to me )

AphoticSketch

Lagrange wrote:

Perhaps some copper slip grease on the disk bolts and get some low temp grease on the pawls inside the hub. (low temp because it can freeze in winter and stop the pawls and you die). (happened to me )

Haha OK will do.

I just did 10k and it's definitely worse now the rotor has more room to oscillate. I tested it as well by pressing the brake slightly while pedaling so my speed didn't change and the vibration and noise went away. It's not great, but I'm glad it's just the brake. Will take it to LBS and get him to grease her up.

Thanks for your help everyone. Much appreciated.

billycool

It's a brand new bike. You shouldn't have to be greasing anything right now.

Take it back and get them to sort it as it could lead to bigger issues later on.

I watched the video but could only hear the hub clicking away.

Alejandrosdog

i only hear the hub ticking over...... if theres tinging from the disc not being centred or out of true, take it back and ask them to set it up properly.

but theres no fun in that, so watch some of the park tool vids and sort it out yourself. That way when you have a problem and youre away from home, youll have some idea what to do to keep going.

and sort out the dog poo

JBA

I can only hear the hub in the video.
There seems to be a lot of scoring/black lines on the rotor. Have you made sure the pads aren't contaminated?
It's hard to tell from the video but it looks to me as if the rotor bolts aren't tight. Check them as well.

If the noise and vibration persist take the bike back to the shop and ask them to check it over. If they are still there afterwards reject the bike and get a refund.

AphoticSketch

Cheers, guys.

You may need to use headphones to hear it, but it also might be out of the range of some people's hearing. The sound disappears when I add weight to the rotor, obviously because I'm altering the resonant frequency of the rotor. I think this noise is then amplified the faster the bike goes, turning into a full on rattle. However, this might be a symptom of a greater issue.

I've spoken to my LBS and gonna pop it into them on Saturday, but in the meantime I'm gonna take the back wheel off and do some debugging. If I can save myself a trip and also any downtime from riding that would be preferable.

Is it possible to test ride a bike without a rear rotor to eliminate that as a potential cause?

larkim

If you're only interested in debugging it yourself and not too bothered about dying in a hideous crash, I suppose you could just remove the rotor and ride at speed somewhere where you know you won't need to suddenly pull the brakes?

steve_sordy

Is the rotor wobbling from side to side?

It may be bent, or it may be mounted out of true.

Remove the rotor and put it on a flat surface, is the rotor actually flat? If it is then there must have been some debris between the rotor and where it was mounted. Clean it all up and remount.

You could do this and you may even find it interesting to do. But the LBS should be sorting this out. Unless the LBS is inconveniently far away, I'd get them to sort it.

AphoticSketch

So I checked the rotor and it is straight as can be. I checked the hub by spinning the wheel and holding each end and it is buttery smooth.

One thing I noticed is the metal insert that goes into the frame and the thru axle screws into was proper loose and I could move the rear derailleur around with the wheel off. Its only held in by a tiny screw which was loose.

I tightened this up and went for a short ride and it has definitely made things better but sadly the problem persists.

The rattle sound is still there and my balls are still vibrating.

I got the bike from Tredz and I don't live anywhere near them as I acquired the bike online. I've emailed them and will get them to come and collect it. I've already spent money trying to get it fixed which Tredz reimbursed me for, but this is ridiculous.