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Makes And Models => Zero Motorcycles Forum | 2013+ => Topic started by: KuRi on March 16, 2020, 10:48:50 PM

Title: Suggested Belt Tension for 2017+ dsr models (wider belt)
Post by: KuRi on March 16, 2020, 10:48:50 PM
Hi!

Sorry to open another thread about belt tension, but now that I have decided to adjust the belt tension by myself I would like to know what belt tension are you putting on newer models.

Most of the threads I have read talk about 25kg, but this value is for older models, with the thinner belt. (range 20-30 is what manual says for those models).

For newer models as mine (2020 dsr) the manual says 25kg-75kg, which seems like a too wide range and I don't know what value to use.

I put 20-25kg trying to fix some vibrations I were getting but the belt looked too loose when pushing by hand. Now I have put 25-30kg and it feels better, but the vibrations are back.

Any help? Thanks!
Title: Re: Suggested Belt Tension for 2017+ dsr models (wider belt)
Post by: DonTom on March 17, 2020, 12:00:50 AM

For newer models as mine (2020 dsr) the manual says 25kg-75kg, which seems like a too wide range and I don't know what value to use.
I would keep it a little more towards the loose end.

The newer wider belts are  not nearly as critical as the older thinner belt. I often just check mine by hand because as long as it isn't too tight, it's not that critical.

-Don-  Auburn, CA

Title: Re: Suggested Belt Tension for 2017+ dsr models (wider belt)
Post by: KuRi on March 17, 2020, 12:15:23 AM
Thanks DonTom, the actual reading is between 25kg and 30kg with the krikit tool and 40Hz with the app.

Does it sound right to you?

CheerS!
Title: Re: Suggested Belt Tension for 2017+ dsr models (wider belt)
Post by: DonTom on March 17, 2020, 01:12:21 AM
Thanks DonTom, the actual reading is between 25kg and 30kg with the krikit tool and 40Hz with the app.

Does it sound right to you?

CheerS!
The spec for the 11 mm belt is  25 kg to 76.5 kg  or 42.5 Hz to 73.6 Hz.

I would prefer to keep mine more in the middle of the range spec, around 50 kg and hope to get around 55 hz or so with the app.

And a credit card width (just a little on the loose side) to the lip on the rear sprocket  for the alignment.

What works for me is to put the belt on the opposite side of the rear sprocket, flush on the rear sprocket right edge when the axle nut is  loose.  Then expect the alignment to be correct when the wheel nuts are all tightened up to spec., a credit card edge width on the left edge to the sprocket lip to about 1MM. A credit card is slightly  less than 1 MM (about 0.8MM) and is close enough. You do NOT want the belt to be touching the lip on left. A credit card edge is the very minimum space  you should have there.

-Don-  Auburn, CA
Title: Re: Suggested Belt Tension for 2017+ dsr models (wider belt)
Post by: KuRi on March 17, 2020, 02:01:21 AM
Thanks again for the help... the problem is that when setting the belt to 35-40kg (measuring with the tool) the belt is veeery tight and it moves very little when pressing with the finger. It looks too tight to me :( (I can share a video if this helps)

The bike came with 25kg-30kg from factory...

I have tried the trick with the belt alignment and it does not work for me. As soon as I move the bike, the belt moves to the left with no space between the lip and the belt :S
Title: Re: Suggested Belt Tension for 2017+ dsr models (wider belt)
Post by: togo on March 17, 2020, 05:53:58 AM
Be careful where the bike is when you measure. 

Tension can vary quite a bit by what point the wheel is in the rotation (sprocket slightly out of round) and whether there is weight on the wheel or if it is up in the air, or whether it is on side stand or held upright.

Consult Zero's owner's manual for authoritative info:
http://media.zeromotorcycles.com/resources/owners-manuals/2020/2020-Zero-Owners-Manual-S-SR-DS-DSR.pdf
P. 6.17
Title: Re: Suggested Belt Tension for 2017+ dsr models (wider belt)
Post by: DonTom on March 17, 2020, 07:56:21 AM

I have tried the trick with the belt alignment and it does not work for me. As soon as I move the bike, the belt moves to the left with no space between the lip and the belt :S
With the rear wheel off the ground, you need to rotate the wheel a few times each time you adjust to see what is happening. It's been a while since I have done it on each of my Zeros, but I didn't have any issues. And the belts stayed where I left them and that was many thousands of miles ago. IIRC, I tightened the wheel a bit and then spin it and then tighten it a bit more and spin it again until I am at spec.

-Don-  Auburn, CA
Title: Re: Suggested Belt Tension for 2017+ dsr models (wider belt)
Post by: KuRi on March 17, 2020, 01:51:29 PM
What is the difference in tension when the wheel is off the ground? higher or lower tension? The tension the manual suggests is measures with the wheel on the ground or off the ground? Thanks!
Title: Re: Suggested Belt Tension for 2017+ dsr models (wider belt)
Post by: DonTom on March 17, 2020, 07:54:49 PM
What is the difference in tension when the wheel is off the ground? higher or lower tension? The tension the manual suggests is measures with the wheel on the ground or off the ground? Thanks!
I have always done it with the wheel off the ground.

But  I often do a quick check by hand and eyes with the wheel on the ground, just to be sure there is nothing is obviously wrong.

-Don-  Auburn, CA

Title: Re: Suggested Belt Tension for 2017+ dsr models (wider belt)
Post by: JaimeC on March 17, 2020, 08:12:34 PM
What is the difference in tension when the wheel is off the ground? higher or lower tension? The tension the manual suggests is measures with the wheel on the ground or off the ground? Thanks!

With a Zero, there really isn't any difference.  For MOST belt-driven motorcycles, the belt is tighter when the suspension is loaded, and looser when it is not.  This is because the swingarm pivot is on a different axis than the drive pulley.  On a Zero, they are on the same axis, so the tension really doesn't change unless the pulleys are ridiculously out of round...
Title: Re: Suggested Belt Tension for 2017+ dsr models (wider belt)
Post by: KuRi on March 17, 2020, 08:35:00 PM
Thank you very much all, very helpful as always!
Title: Re: Suggested Belt Tension for 2017+ dsr models (wider belt)
Post by: KuRi on March 18, 2020, 06:34:43 PM
I contacted Zero Europe today to know what 25kg-75kg range means... because it is too big...

Their answer has been: "look at the manual"...

I really can't understand why people does not spend 1 more minute trying to understand my question, because... where do you think I obtained the 25kg-75kg information???

Very dissapointed with the support from Zero Europe :(

P.D: They also asked me to not contact them again for those kind of questions and they told me to contact my local dealer, which does not have even a belt tension measuring tool... and last time adjusted my tension by "eye" and "finger" measurements... leaving the tension below 20kg... Premium Brand with Premium Support??? Premium prices indeed xD

With my last bike (BMW) I went to the dealer several times for several issues and after some patience, they solved all of them. They were very professional and experienced technicians.
Title: Re: Suggested Belt Tension for 2017+ dsr models (wider belt)
Post by: JaimeC on March 18, 2020, 07:33:45 PM
Just put it in the middle of that range.  That's what I do.  If you like, go towards the looser end as belts get tighter as they age (not looser as many people would guess).
Title: Re: Suggested Belt Tension for 2017+ dsr models (wider belt)
Post by: KuRi on March 18, 2020, 08:10:14 PM
Thanks JaimeC, I tried 35kg and after I ride it became 50kg and was too tight... so much I was scared and put 30kg again when cold.

I would like to know your opinions because if everybody says that 50kg (in cold!) is good and nothing will break, I will use that. So again, thanks for your help.
Title: Re: Suggested Belt Tension for 2017+ dsr models (wider belt)
Post by: DonTom on March 18, 2020, 09:27:35 PM
Thanks JaimeC, I tried 35kg and after I ride it became 50kg and was too tight... so much I was scared and put 30kg again when cold.

I would like to know your opinions because if everybody says that 50kg (in cold!) is good and nothing will break, I will use that. So again, thanks for your help.
Could it have something to do with your gauge or the way it's being used? I just don't see how being near the middle of the spec could be "too tight". Seems like things are not adding up correctly if the middle of the spec seems too tight.

-Don-  Auburn, CA
Title: Re: Suggested Belt Tension for 2017+ dsr models (wider belt)
Post by: JaimeC on March 18, 2020, 09:47:33 PM
Thanks JaimeC, I tried 35kg and after I ride it became 50kg and was too tight... so much I was scared and put 30kg again when cold.

I would like to know your opinions because if everybody says that 50kg (in cold!) is good and nothing will break, I will use that. So again, thanks for your help.

According to Zero's specs, 50kg is NOT too tight... over 75kg would be.  50kg is right in the middle.
Title: Re: Suggested Belt Tension for 2017+ dsr models (wider belt)
Post by: KuRi on March 18, 2020, 10:10:54 PM
In fact, both the Gates App and the Krikit tool show it is near the loose end:

Krikit: 30-35kg
Gates App: 45Hz

So maybe it is just my feeling and the belt should be more tight. I have looked a lot of videos of motorcycle belts and they always seem a bit loose, not as tight as mine with 50kg on it.

The weird thing is... if they want you to put 50kg on it... what give such a big range??? Why not just say 40kg-60kg :D :D :D

Thanks !
Title: Re: Suggested Belt Tension for 2017+ dsr models (wider belt)
Post by: KuRi on March 19, 2020, 12:01:11 AM
One last note (I don't want to bother you anymore)...

I have set the tension to 35kg-40kg when cold, and the bike accelerates faster. I had never drifted before, and today the rear wheel drifted several times in sport mode when starting from a stop ^^
Title: Re: Suggested Belt Tension for 2017+ dsr models (wider belt)
Post by: JaimeC on March 19, 2020, 12:09:28 AM
Makes sense.  Less strain on the bearings.  BTW, other bikes HAVE to be on the loose side, because when the bike is loaded, the swingarm stretches the belt tightening it up.  When there isn't any load, The swingarm doesn't stretch the belt as much.  It's also why chain-drive bikes HAVE to have free play.  Because of the way Zeroes are set up, the tension is constant no matter what the swingarm is doing.

Over time the belt will get tighter because the carbon/kevlar belt doesn't stretch, but the rubber with the teeth swells as it gets older.  That reduces the inner circumference of the belt which makes it tighter.