Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Uhao]

My '20 SR/F w/ < 300 miles has a pulsing whining noise ~ 25 mph. Zero tech support has said that this problem is very usual...return to dealer for further analysis. I have no dealership within reasonable range due to oceans abound.

Belt tension is within specs (62, 70, 72kg...) using the Gates tension device. Belt is riding near the sprocket (wheel) hub flange w/ ~ 0.004" gap.

I assume I could re-align the hub by adjusting the right/left bolts so the belt tracks on the center...

Wil increasing mileage break in the Gates belt?

Any suggestions?

[TheRan]

Is that much belt tension variation typical? Could be that the rear sprocket is out of round or not centred (I would think the front sprocket is to small to have an significant impact, plus being mounted on a shaft it should run fairly true).

[Uhao]

Using the Gates gauge takes time getting the right feel...I did rotate the belt, then take another measurements. Just wanted to convince myself belt tension was NOT problem.

I think I need to align the hub so the belt tracks more in the middle, away and not riding so close to the sprocket flange.

Thanks for the comment...I'm hoping someone has had a similar noise.

Stay safe everyone!

[MBldc]

My SRF had a pulsing whining at slow speeds too, escpecially when recuperating. It got better with mileage. If acceleration itself feels smooth, I would not think it is a serious out of round issue. Also, in my case the whining was synchron with belt revolution, so I think it is the belt itself.
Align the Belt to not rub the rear sproket flange, as you allready did, and keep it on the lower tension limit. A little amount of silicone oil applied only to the Belt flanges also helps. Keep your Belt and sprockets clean and carefully inspect the sprocket for debris. One time I suddenly felt a strange High frequent Oscillation in the footpegs. I then found this to be caused by a tiny piece of crushed tarmac, that was trapped in one tooth of the rear sprocket..

[KuRi]

I think that is normal. I have something similar in my dsr 2020, together with the whining noise I have a small pulse that can be felt on my left foot, both are synchronized.

I have tried all kind of adjustments (tension, alignment, suspension, ...) and it changes a little bit but never dissapear.

If it is not affecting smoothness, acceleration, speed or anything else (just noise) I would not worry too much, if any at all

Electric motors have different whine noises and other noises and they are different even within the same model. I have a giant bicycle with a replaced motor that has a high pitch whine noise that the original did not have, but everything is running smooth so the dealer is not replacing the motor again.

[Uhao]

All good info, thanks. I have been calling several Zero service departments, and the ones where I had good conversation, seem to point to..."put some mileage on the bike, monitor the noise/belt (tension & debri) and most likely noise will disappear or lessen.

Maybe reducing the tension to the lower tolerance of the spec and positioning the belt more in the center of the hub as I put mileage on the blke...

[Kappi]

My SR does the same thing.
Upon tire change it turned out that the rear sprocket is mounted ever so slightly off-center.
That creates a 5 kg variation in belt tension. Nothing to worry about, though.
Technician (non-zero) told me he knows this phenomenon from many ICE bikes with belt drive, however there the engine noice and vibration mask the symptom.
The issue is only more predominant on Zeros due to the large diameter of the rear sprocket.

Kappi

[Hene]

I have had this whining noise too in my DSR 2018 from day one. First I turned rear sprocket on a lathe to be absolutely true, changed the belt few times, adjusted center position of belt hundred times. Nothing worked. Then bought a new rear sprocket, checked with dial... a little more better.

But now I have adjusted the motor position slightly, and the rear adjustment is as far as possible from the edge, not too tight and belt cleaned with WD-40, I have absolutely silent belt finally.

[2020_SRS_Commuter]

On my SRS, using the Gates app, there is a 8hz difference between two different positions of the rear wheel, 180 degrees apart, naturally.

I have no metric yet for the difference in tension with the Kricket tool because it broke... stopped clicking after a few uses. A replacement is on the way.

On my SRS, the tension shown on the app is 10hz lower when the axle nut is loose vs when the axle nut is torqued to 75.

A good test to be sure you are hearing the belt and not the motor is ride without a helmet, at speeds low enough that wind noise doesn't buffet your ears, then at that speed turn off the motor with the kill switch and listen to the belt as you slow.

[jonblow]

I’ve had the same on my srf since new. I think it’s normal and sounds like a whale call lol.
It also seems more pronounced when the belt is wet.