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[tyzbit]

I bought my Zero 3 weeks ago, and I noticed two things:

• I hear the brakes squeak occasionally, and the front hub does too in the right conditions
• The motor makes a cyclic whumping noise around 30mph that matches the RPMs and goes away below 20 and above 40

I mentioned both to the dealer and they repacked the grease on the seals for the front wheel, but basically cautioned me about the noise and said to bring it back in if it gets worse.

Has anyone else had experience with motor noises, and did they affect anything like how long the belt lasted?

edit: here's a recording of it https://instaud.io/3wuS

[Curt]

Mine came noisy from the factory. The belt tension was over 100 kg. After setting it to 25 kg (using Krikit gauge) it became much quieter, presumably because the motor bearings are under less lateral force.

[tyzbit]

Mine came noisy from the factory. The belt tension was over 100 kg. After setting it to 25 kg (using Krikit gauge) it became much quieter, presumably because the motor bearings are under less lateral force.

My tension is at 50kg.  I bet if I adjust it, it'll "reset" how the belt contacts the motor.  I'm just not sure that 50kg warrants adjusting.

[BamBam]

Adjusting belt tension is an easy procedure.  I would recommend that you set the belt to the minimum specified tension and make sure you have it positioned on the rear sprocket so there is about a millimeter or so clearance between the belt and the outside shoulder of the sprocket.

[alko]

Mine came noisy from the factory. The belt tension was over 100 kg. After setting it to 25 kg (using Krikit gauge) it became much quieter, presumably because the motor bearings are under less lateral force.

My tension is at 50kg.  I bet if I adjust it, it'll "reset" how the belt contacts the motor.  I'm just not sure that 50kg warrants adjusting.

50 kg is too tight. 25 kg is just right and you will feel and hear the difference. Well worth the hassle imo.

[Richard230]

Mine came noisy from the factory. The belt tension was over 100 kg. After setting it to 25 kg (using Krikit gauge) it became much quieter, presumably because the motor bearings are under less lateral force.

My tension is at 50kg.  I bet if I adjust it, it'll "reset" how the belt contacts the motor.  I'm just not sure that 50kg warrants adjusting.

50 kg is too tight. 25 kg is just right and you will feel and hear the difference. Well worth the hassle imo.

Did you see the belt tension for the new SR/F model?  I think it was something like 115kg.   

[alko]

Did you see the belt tension for the new SR/F model?  I think it was something like 115kg.   
[/quote]

I just looked at the sr/f owners manual and it says 51-102kg. Not sure why the wide margin.
For my 2017 dsr and everything else but the S model, it says about 25kg. I wonder if the sr/f has a longer belt so needs the extra tension.

[domingo3]

I just looked at the sr/f owners manual and it says 51-102kg. Not sure why the wide margin.
For my 2017 dsr and everything else but the S model, it says about 25kg. I wonder if the sr/f has a longer belt so needs the extra tension.

It's not "about 25kg", it's 25-76.5 kg for the new, improved "wide" belt that started in 2017.  The previous "narrow" belt tension spec was 20-30 kg.

The SR/F has an even beefier belt, presumably because the torque is higher. 

I'd agree with BamBam that it's probably best to keep the tension closer to the minimum.  When I had my 2016 with the narrow belt, I had to adjust a couple of times a year to keep it within the range.  I think even without the effects of wear, change in temperature caused it to fluctuate enough to need adjustment with the seasons.

[Richard230]

I just looked at the sr/f owners manual and it says 51-102kg. Not sure why the wide margin.
For my 2017 dsr and everything else but the S model, it says about 25kg. I wonder if the sr/f has a longer belt so needs the extra tension.

It's not "about 25kg", it's 25-76.5 kg for the new, improved "wide" belt that started in 2017.  The previous "narrow" belt tension spec was 20-30 kg.

The SR/F has an even beefier belt, presumably because the torque is higher.

That might be good for transmitting power to the rear sprocket, but I wonder what impact it has on the life of the motor and wheel bearings? My 2018 S came from the factory with 75kg tension on the belt. So it appears that the people assembling the bikes feel that they need to set the tension at the high end of the specifications.  I wonder why?  Do they believe that the tension will decrease as the belt wears?

[ecavoli]

I recently had the belt replaced on my 2017 FXS and now have a louder and deeper than normal whine, most noticeable at low rpms, when "taking off."
Is this also typically symptomatic of a belt tension issue as well?  Thoughts appreciated.

[BamBam]

I recently had the belt replaced on my 2017 FXS and now have a louder and deeper than normal whine, most noticeable at low rpms, when "taking off."
Is this also typically symptomatic of a belt tension issue as well?  Thoughts appreciated.

The best way to keep the belt noise at a minimum is to follow these 3 simple steps:
1)  Keep belt tension at minimum spec range.
2)  Adjust so 1mm gap between belt and sprocket shoulder.
3)  Keep belt and pulleys/sprockets clean using soap and water.  Dawn liquid dish detergent works well.

[domingo3]

I just looked at the sr/f owners manual and it says 51-102kg. Not sure why the wide margin.
For my 2017 dsr and everything else but the S model, it says about 25kg. I wonder if the sr/f has a longer belt so needs the extra tension.

It's not "about 25kg", it's 25-76.5 kg for the new, improved "wide" belt that started in 2017.  The previous "narrow" belt tension spec was 20-30 kg.

The SR/F has an even beefier belt, presumably because the torque is higher.

That might be good for transmitting power to the rear sprocket, but I wonder what impact it has on the life of the motor and wheel bearings? My 2018 S came from the factory with 75kg tension on the belt. So it appears that the people assembling the bikes feel that they need to set the tension at the high end of the specifications.  I wonder why?  Do they believe that the tension will decrease as the belt wears?

I wouldn't assume that the tension at delivery is indicative of what anyone believes.  My 2016 FXS, which should have had a maximum tension of 30 kg, was delivered with a tension that was off the scale on the krikit gauge (>70 kg).  I assume that it's best to keep the belt tension as low as possible to extend the life of the motor and wheel bearings.  I also assume that the minimum spec on the tension is to preclude ratcheting.

[tyzbit]

Just following up on this after getting all the tools I needed to adjust the belt tension (I didn't even have crescent wrenches )

I adjusted the belt to ~30kg and the noise is gone; from what I can hear it sounds like there's still VERY faint harmonics at certain RPMs but it's a night and day difference.

Listen for yourself: https://instaud.io/3xlW (first is before it was fixed as I was coming home, the rest are after it was fixed from low or no speed.)

Thank you Curt, BamBam, alko and everyone else for guiding me in the right direction for an easy fix.

[tyzbit]

So after adjusting my belt tension, I now have a squeak that manifests when at neutral acceleration and goes away when braking.  Some videos:

Manually turning the wheel


I get a good closeup of my brake pads here, and from what I can tell the inner pads have a little clearance and the outer pads have basically none.

Using the motor


Notice the hub; it oscillates up and down as the wheel turns - is this an indication that my wheel is unbalanced/off-center?  It seems to stay in rhythm with the squeaking.

Things I've tried:

• Re-setting the axle nut a few times after adjusting the wheel side-to-side when loose (always to 75 ft-lbs)
• Braking hard to try to get the calipers to extend out a bit more when relaxed
• Washing the caliper and pads gently with water
• Removing just a bit of brake fluid (the reservoir was past the top fill line, now it's right at it).  I'm hesitant do do any more.

I've gone through a lot of YouTube tutorials and all through the official and unofficial manual but nothing precisely covers what's happening to me, and what generally covers me is: "start replacing things, starting with your brake pads and working up"

[alko]

That's an annoying chirp. It may or may not matter, but is your belt properly alligned. I know it took me a few tries to get the belt aligned perfectly with about 1 mm clearance on both sides.