Whining noise coming from RX3 wheels

[RX3James]

Ok this is something that has me a little concerned. My RX3's wheels make a pretty loud whining noise that gets progressively louder the faster wheel turns. I can hear it over the engine as i'm riding a little bit but it becomes very noticable when I pull in the clutch and let the bike roll. What could possibly be causing this? The brake pad rubbing on the rotor or maybe the wheel bearing being bad or needing lube? There is 987 miles on the bike as of now so maybe the brake pads havent fully bedded in yet? I love the bike and I love riding it but like I said this has me concerned. So... I made a video with my GoPro so all of you can take a listen and tell me if i'm crazy or not or if this is a completely normal sound for a new bike or if the front wheel is gonna fly off and I shouldn't be riding the bike any more! (Which I really doubt) Any way i'm extremely anxious to hear your opinions. Thanks!

James

[SpudRider]

I suggest you remove the front wheel, and inspect the wheel bearings. After the wheel and left spacer are removed, rotate each wheel bearing with your index finger. If either bearing rotates with intermittent notches, I suggest your replace the bearing.

If the bearings rotate smoothly, I suggest you replace the stock brake pads with EBC FA185, or equivalent, Honda brake pads. You can learn more about front brake pads by reading the following thread.

http://www.chinariders.net/showthread.php?t=15503

Does your front brake pulse when you apply the brakes hard? Are you noticing uneven wear on the front brake rotor?

[AZRider]

Try lifting the front wheel off the ground and rotate it to try and isolate the sound. In some instances, what sounds like it's coming from the front may in fact be from the rear. In addition to Spud's excellent advice, check the speedometer drive.

[RX3James]

Yes the front brake does pulse when it's applied. The rotor looks to be uniform all the way around and doesn't seem to have uneven wear. I took a really close look at the brake pad and it looks like it's touching the rotor even when the brake lever isn't pressed. I'm going to take the front wheel off and look at the bearings tomorrow. I might be contacting CSC about a new front rotor and a new set of wheel bearings depending what I find.

[rjmorel]

Did CSC put this bike together for you? I think if you can get the front end up off the ground and give it a spin and see if it rotates and sounds smooth, would be first check. If you don't have center stand, have someone else spin the tire while you pull the bike back over on the side stand and rear wheel lifting the front wheel . If not sounding good, then follow Spuds suggestion and take it off and feel the bearings by hand.
Also I'm wondering if your chain is too tight and grinding on the plastic wear bars on the swing arm?
You will need a micrometer or dial caliper to measure the rotor thickness in 4-5 places to measure the thickness and see if it varies. Mine had a difference of .005". I think stock they are around .151 when new. Should be within .001 thickness all the way around I would think.
Just throwing all this out for you but really not sure, rj

[Weldangrind]

Plenty of excellent guidance offered above.

I'll add that if you raise the front end, spin the wheel and hear noise, remove the front caliper and spin the wheel again. Does the noise disappear?

[rjmorel]

When free spinning the front wheel , the brake pads on my RX3 will make a slight scraping sound ,that's normal on all bikes I think, but nothing like what we're hearing in your video. That noise is either bearings, chain rubbing, or something else that is rubbing where it shouldn't. Hard to tell. rj

[SpudRider]

Originally Posted by Weldangrind

Plenty of excellent guidance offered above.

I'll add that if you raise the front end, spin the wheel and hear noise, remove the front caliper and spin the wheel again. Does the noise disappear?

I agree with the others. Before you remove the front wheel, lift the front wheel and spin it, while listening for noise. Then remove the brake caliper, and listen again. If the noise disappears after the caliper is removed, the bearings are probably okay. In fact, with a new Zongshen bike, I'm pretty confident the bearings are good.

If the noise disappears, the problem must be either the brake rotor, and/or the brake pads. Remove the front wheel from the bike. Examine the bearings as I described above. Using a socket ratchet with an Allen key socket, you can remove all the brake rotor bolts. Be careful not to strip the Allen heads. You might need to apply some heat to the bolts with a propane torch. After all the bolts are removed, lift the rotor off the hub. Then re-install the rotor, incrementally tightening the 6 bolts in a star pattern.

Put the wheel back on the bike, re-attach the brake caliper, and spin the wheel once again, listening for noise. If the bearings are good, and you still hear a noise, contact CSC and have them send you a new brake rotor.

I still recommend you install EBC FA185 brake pads, or the Honda equivalent.

[NoVa Rider]

RX3james, I was just reading your update on your poor fuel economy, and I was wondering if there was something dragging on your bike. Then I saw this new thread about your wheel noise. Probably coincidence but worth considering. Good advice from other posters but something quick you might check. If you start rolling bike down a mild slope with transmission in neutral, does bike seem to roll freely?

[Weldangrind]

Originally Posted by SpudRider

You might need to apply some heat to the bolts with a propane torch.

A heat gun is also a good way to heat the bolts. Whichever method you choose, take care to not apply excessive heat.

[Weldangrind]

Originally Posted by NoVa Rider

RX3james, I was just reading your update on your poor fuel economy, and I was wondering if there was something dragging on your bike. Then I saw this new thread about your wheel noise. Probably coincidence but worth considering. Good advice from other posters but something quick you might check. If you start rolling bike down a mild slope with transmission in neutral, does bike seem to roll freely?

Excellent deduction! I'll be curious to find out if there is a link to poor fuel economy in this case.

[RX3James]

When I did the valve adjustment I had the bike on the center stand. I remember spinning the front wheel and hearing a sshh sshh sshh sshh sound coming from the brake caliper on different parts of the rotor. I never really put too much thought into it because I figured it was because the brake pads were still bedding in. I'm gonna throw it up on the center stand tonight after work and see if I can still hear the sound. If I still hear it then i'm gonna give the guys at CSC a quick call and ask them to send me a new front rotor.

Originally Posted by SpudRider

I agree with the others. Before you remove the front wheel, lift the front wheel and spin it, while listening for noise. Then remove the brake caliper, and listen again. If the noise disappears after the caliper is removed, the bearings are probably okay. In fact, with a new Zongshen bike, I'm pretty confident the bearings are good.

If the noise disappears, the problem must be either the brake rotor, and/or the brake pads. Remove the front wheel from the bike. Examine the bearings as I described above. Using a socket ratchet with an Allen key socket, you can remove all the brake rotor bolts. Be careful not to strip the Allen heads. You might need to apply some heat to the bolts with a propane torch. After all the bolts are removed, lift the rotor off the hub. Then re-install the rotor, incrementally tightening the 6 bolts in a star pattern.

Put the wheel back on the bike, re-attach the brake caliper, and spin the wheel once again, listening for noise. If the bearings are good, and you still hear a noise, contact CSC and have them send you a new brake rotor.

I still recommend you install EBC FA185 brake pads, or the Honda equivalent.

[RX3James]

Yes CSC did put the bike together for me. I never thought of looking at the chain i'll inspect that tonight when I get home from work. I have a digital dial caliper that i'll be using when I inspect the brake pads and rotor thickness. I'll post pics of what I find. Thanks for all the help guys I really appreciate it!

Originally Posted by rjmorel

Did CSC put this bike together for you? I think if you can get the front end up off the ground and give it a spin and see if it rotates and sounds smooth, would be first check. If you don't have center stand, have someone else spin the tire while you pull the bike back over on the side stand and rear wheel lifting the front wheel . If not sounding good, then follow Spuds suggestion and take it off and feel the bearings by hand.
Also I'm wondering if your chain is too tight and grinding on the plastic wear bars on the swing arm?
You will need a micrometer or dial caliper to measure the rotor thickness in 4-5 places to measure the thickness and see if it varies. Mine had a difference of .005". I think stock they are around .151 when new. Should be within .001 thickness all the way around I would think.
Just throwing all this out for you but really not sure, rj

[RX3James]

Ok guys here's the update.

After taking a look at my front rotor it is definitely warped. The thickness of it is actually uniform at each point I measured however there is a definite bowing that can be seen by the naked eye as the rotor turns. That I'm 100% positive is the cause of the pulsing front brake and maybe a little bit of noise coming from the front end..

The loud pulsing whining noise that you can hear in the video actually appears to be coming from the chain. A good buddy of mine who is a pretty talented motorcycle mechanic took a ride on it today and he pointed out the actual location where the noise is coming from. After hearing the noise from a different perspective it was pretty obvious where it was coming from. So we took a look at the chain. It appears to have the correct tension so I don't think it's too loose or too tight. I do believe my rear sprocket is out of round which is causing the rapid tensionin and loosening of the chain which is causing the noise. I checked the sprocket bolts for tightness just to make sure the sprocket alignment was true and they were definitely tight.. so tight in fact that it took 20 solid minutes of heating with a torch to break one of them free!!

Ok so tonight I'm going to e-mail CSC and explain the front rotor and rear sprocket and ask them to send me new ones.. and with new hardware too because I'm not 100% sure the factory hardware will be usable again..

[Weldangrind]

Another member reported that when he removed his front rotor, it sprung back to being perfectly flat. Perhaps you'll find the same thing.