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Makes And Models => Zero Motorcycles Forum | 2013+ => Topic started by: AGTster on September 04, 2013, 10:09:33 AM

Title: Squealing on rear tire at slow speed?
Post by: AGTster on September 04, 2013, 10:09:33 AM
2013 Zero S. Rolling at low speed (5-10mph), I have a squeal with every rotation of the back tire. When I apply the rear brake, the squeal is gone. Let go of brake, it squeals again. Anyone experience the same? Any suggestions on fix?

Thank you!

- AGT
Title: Re: Squealing on rear tire at slow speed?
Post by: DesignerDan on September 04, 2013, 10:21:50 AM
Mine does it too. It's the disc rubbing against one of the brake pads. With an ICE bike the sound is masked by the engine so no one really notices. On the Zero it gets quite annoying. There's no good solution. The caliper slides freely left and right so when you release the brake usually one of the pads is still ,ever so slightly, contacting the disc. After the pads break in the noise might go away.

On the topic of noises, my belt makes an annoying harmonic/resonating noise at ~16 mph. My belt is the proper tension so I guess it's just something we will have to live with.
Title: Re: Squealing on rear tire at slow speed?
Post by: AGTster on September 04, 2013, 12:02:55 PM
DesignerDan, response much appreciated. So it sounds like you're saying "not much can be done about it, see if it goes away with some breaking in"? That's probably true, but what a annoying bummer. The whole quiet thing doesn't count is the tires are squealing...Esp annoying in the office garage where it reverbs on the walls. Arg!

I don't have the harmonic belt vibration though.
Title: Re: Squealing on rear tire at slow speed?
Post by: NoiseBoy on September 04, 2013, 03:18:50 PM
Try putting a bit of copper grease on the pin and on the back of the pads.  This always worked for my ICE bikes.
Title: Re: Squealing on rear tire at slow speed?
Post by: Richard230 on September 04, 2013, 08:51:45 PM
You can try cleaning the disc and brake pads with soapy water, flush with low-pressure clean water, wipe dry and ride around to warm the caliper to get any remaining water out of the caliper area.  The squeaking might be caused by an accumulation of brake dust and if so this procedure will clean the dust off of the disc and caliper and eliminate the noise - for a while.
Title: Re: Squealing on rear tire at slow speed?
Post by: BrianTRice@gmail.com on September 07, 2013, 04:33:57 AM
Mine does it too. It's the disc rubbing against one of the brake pads. With an ICE bike the sound is masked by the engine so no one really notices. On the Zero it gets quite annoying. There's no good solution. The caliper slides freely left and right so when you release the brake usually one of the pads is still ,ever so slightly, contacting the disc. After the pads break in the noise might go away.

On the topic of noises, my belt makes an annoying harmonic/resonating noise at ~16 mph. My belt is the proper tension so I guess it's just something we will have to live with.

Oh, thanks for the explanation on both points. I noticed the 16mph "whistle" and honestly I use it around parking lot areas (at slightly slower speeds) to give myself a little noise to work with in case others don't hear me. I don't find it a nuisance.
Title: Re: Squealing on rear tire at slow speed?
Post by: DesignerDan on September 07, 2013, 04:52:08 AM
Mine does it too. It's the disc rubbing against one of the brake pads. With an ICE bike the sound is masked by the engine so no one really notices. On the Zero it gets quite annoying. There's no good solution. The caliper slides freely left and right so when you release the brake usually one of the pads is still ,ever so slightly, contacting the disc. After the pads break in the noise might go away.

On the topic of noises, my belt makes an annoying harmonic/resonating noise at ~16 mph. My belt is the proper tension so I guess it's just something we will have to live with.

Oh, thanks for the explanation on both points. I noticed the 16mph "whistle" and honestly I use it around parking lot areas (at slightly slower speeds) to give myself a little noise to work with in case others don't hear me. I don't find it a nuisance.

My bike also makes a high pitch noise at exactly 19 mph. This might be the "whistle" you are describing. That noise is coming from the motor. From my expirence, brushless dc motors are notorious for making high pitch noises at certain RPMs. The noise I previously described is coming from the belt and its not constant it's more of a: whirrrrrr whirrrrrrre whirrrrrrr whirrrrrrre whirrrrrrr... You get this idea.
Title: Re: Squealing on rear tire at slow speed?
Post by: BrianTRice@gmail.com on September 07, 2013, 05:51:04 AM
Oh, thanks for the explanation on both points. I noticed the 16mph "whistle" and honestly I use it around parking lot areas (at slightly slower speeds) to give myself a little noise to work with in case others don't hear me. I don't find it a nuisance.

My bike also makes a high pitch noise at exactly 19 mph. This might be the "whistle" you are describing. That noise is coming from the motor. From my expirence, brushless dc motors are notorious for making high pitch noises at certain RPMs. The noise I previously described is coming from the belt and its not constant it's more of a: whirrrrrr whirrrrrrre whirrrrrrr whirrrrrrre whirrrrrrr... You get this idea.

I see. That is different. I'll have a listen again and see whether there are two sounds going on. I only really notice the high pitch noise. And nothing bothers me except for brake squeaking.
Title: Re: Squealing on rear tire at slow speed?
Post by: DesignerDan on September 07, 2013, 08:55:43 AM
Oh, thanks for the explanation on both points. I noticed the 16mph "whistle" and honestly I use it around parking lot areas (at slightly slower speeds) to give myself a little noise to work with in case others don't hear me. I don't find it a nuisance.

My bike also makes a high pitch noise at exactly 19 mph. This might be the "whistle" you are describing. That noise is coming from the motor. From my expirence, brushless dc motors are notorious for making high pitch noises at certain RPMs. The noise I previously described is coming from the belt and its not constant it's more of a: whirrrrrr whirrrrrrre whirrrrrrr whirrrrrrre whirrrrrrr... You get this idea.

I see. That is different. I'll have a listen again and see whether there are two sounds going on. I only really notice the high pitch noise. And nothing bothers me except for brake squeaking.


It's frustrating because my bike didn't used to make the noise. After the 3000 miles mark my belt was starting to get too loose and Zero recommends retensioning the belt every 2500 miles. The noise only started after I retensioned it. At first I thought I did something wrong but I followed Zero's instructions exactly and used a tension gauge. I tried loosening the belt a bit but the noise was still there so I went back to the recommended tension. The noise sounds very much like a car with a squeaky engine belt. But it only happens at ~16 mph and its a deep noise. I checked the sprocket alignment and that was good. My rear wheel axle is perfectly positioned on each side of the swing arm. I even took the belt off and spun the motor and rear wheel without the belt and couldn't recreate the noise so I'm 98% it's the belt that's makes the noise. It's weird how the noise only started after I retensioned the belt :( oh well there's nothing I can do about it.
Title: Re: Squealing on rear tire at slow speed?
Post by: kensiko on September 07, 2013, 03:34:24 PM
What about using a spray for rubber belts (I think it's silicon based)? It may temporarily help. I don't know if it's a bad idea on traction belts.
Title: Re: Squealing on rear tire at slow speed?
Post by: JohnSki on September 09, 2013, 01:11:52 AM
Here is a link to a guy that had a bunch of belt noise on a Corbin Sparrow.  He started using a pure PTFE (Teflon) aerosol spray from Kano Laboratories but then found a 1/2 inch squeeze of Radio Shack Teflon Lube Gel to work much longer.http://www.los-gatos.ca.us/davidbu/sparrow/s_diary.html (http://www.los-gatos.ca.us/davidbu/sparrow/s_diary.html)
Title: Re: Squealing on rear tire at slow speed?
Post by: NoiseBoy on September 13, 2013, 11:16:45 PM
Ive noticed something recently on my bike that may be a similar issue AGTster,  If i very lightly apply the rear brake just to activate regen when crawling in traffic I get quite a loud squealing sound just as you describe around 5-10mph.  If i brake harder it disappears.   So I wonder if your brake is binding slightly?  It might be worth just pushing the pads back slightly and going for a ride around the neighborhood to see if it cures the noise.  If it does you know there is something causing the brake to apply even when you arent stepping on the pedal.

Do you leave your foot on the pedal or do you leave your foot back or to the side and just shift it into position when you need to brake?
Title: Re: Squealing on rear tire at slow speed?
Post by: mehve on September 14, 2013, 09:44:13 PM
Leaving the highway, some mighty squeaking has been going on this last week. My brake fluid (front) seemed low and now is a darker color, so I'll need to flush it out I imagine (never done it before... git tips?) and get fresh fluid in there. Does dirty fluid have anything to do with it? I think the rear is the same. The squeak goes away after a while after repeatedly applying the brakes at lower speeds, but it lingers. :(

Do you guys use a specific stand to keep your bike upright? I have one of those stool-looking things but I'd have to physically lift the bike a few inches to get it up on it at the lowest setting and I'm no cyborg...:/
Title: Re: Squealing on rear tire at slow speed?
Post by: mehve on September 14, 2013, 09:53:08 PM
Forgot to mention I've got over 2,200 since I bought my 2013 S ZF11.4. I had brake squealing that went away between 1200-2200 miles. Not sure why it's back with a vengeance. :/

+m
Title: Re: Squealing on rear tire at slow speed?
Post by: NoiseBoy on September 14, 2013, 11:07:03 PM
Leaving the highway, some mighty squeaking has been going on this last week. My brake fluid (front) seemed low and now is a darker color, so I'll need to flush it out I imagine (never done it before... git tips?) and get fresh fluid in there. Does dirty fluid have anything to do with it? I think the rear is the same. The squeak goes away after a while after repeatedly applying the brakes at lower speeds, but it lingers. :(

Do you guys use a specific stand to keep your bike upright? I have one of those stool-looking things but I'd have to physically lift the bike a few inches to get it up on it at the lowest setting and I'm no cyborg...:/

A rear paddock stand is much easier mehve.  I used to use an MX 'stool' stand with my KTM but that was a 120kg bike and very tall so the stand slid underneath easily.  I think the 11.4 would exceed the max rating of most of those stands anyway.  For changing brake fluid a one way valve makes life a lot easier.  The one I use is no longer made but you must be able to get something similar.  The trick is not to open the bleed nipple too far so that you still feel resistance when squeezing the lever.  You can do it without a valve but that realistically requires two people.  You open the nipple, squeeze the lever slowly, then tighten it again before releasing the lever.  Make sure you keep the reservoir topped up so you don't suck air through.  When you see clear fluid coming out you are done, top up to the correct level and then tie the brake lever back to the bar with a cable tie and leave overnight so any bubbles remaining will rise to the reservoir.  Big tip is never pull the lever quickly, if you do the master cylinder will suck air past the seals and then you have to bleed from the lever end to clear it which is a pain in the neck and usually means spilt fluid.

Keep some rags or paper toweling close to hand, any spillages need to be cleaned thoroughly and quickly as brake fluid is extremely corrosive to paintwork and even anodising and powder coating.
Title: Re: Squealing on rear tire at slow speed?
Post by: mehve on September 14, 2013, 11:52:14 PM
Thanks, Noiseboy!

Would any rear paddock stand do? Or is there a specific one (or size) that I need to get? Where would it connect to? (I'll dig up my manual again, I may have missed it...?)

+m
Title: Re: Squealing on rear tire at slow speed?
Post by: NoiseBoy on September 16, 2013, 01:43:47 AM
You can buy paddock stands with generic rubber L shaped pads that fit any swingarm which is what you need.

Most bikes have a threaded hole on each side where you can screw in cotton reel shaped bolts. This is much more secure but the Zeros don't have it. I have no idea why.
Title: Re: Squealing on rear tire at slow speed?
Post by: hinse on October 12, 2013, 04:57:14 AM
I tried automotive grease less silicone spray for door gaskets on mine.
Back to super quietness....

You have to re-apply after rain though.