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Makes And Models => Zero Motorcycles Forum | 2013+ => Topic started by: Bill822 on August 12, 2019, 04:35:06 AM

Title: SR/F belt breaks on test ride video. Has anyone else broken an SR/F belt?
Post by: Bill822 on August 12, 2019, 04:35:06 AM
This video kind of spooked me. Has anyone else broken an SR/F belt or even heard of one breaking?
The worrying part was that he was on a flat and level road, not jumping curbs or hitting a pothole. Start carrying a spare belt? Maybe so.

https://www.youtube.com/watch?v=fOMwuhotyng
Title: Re: SR/F belt breaks on test ride video. Has anyone else broken an SR/F belt?
Post by: DonTom on August 12, 2019, 08:43:15 AM
This video kind of spooked me. Has anyone else broken an SR/F belt or even heard of one breaking?
The worrying part was that he was on a flat and level road, not jumping curbs or hitting a pothole. Start carrying a spare belt? Maybe so.
Read reply number 13 here. (http://electricmotorcycleforum.com/boards/index.php?topic=9158.0)

But many belts last many thousand of miles.

Also, a small rock can get between the belt and the sprocket. Even while on payment.

But belts do not always break the same instant they are damaged. The damage can be done even before the belt is put on the bike. There are many ways to mishandle a belt. Such a prying on it, or even bending it smaller than the smallest sprocket that it will be used on. Such a belt may even last a few thousand miles before it snaps from the damage done months ago. Belts out of alignment can also cause problems. Many possibilities, and many of the reasons  are just based on pure bad luck. A belt can snap in it's first 50 miles just like it's possible to get a flat tire in the first 50 miles. And that did happen to me on my DR200SE!  That was two days after I purchased it, hard to say when it  picked up the screw that I found in the tire. Could have happened right on the dealer's lot!  I will never know. Belts can be like that also.

The SR/F has a thicker belt than any other Zero motorcycle. I doubt them breaking will be more  common  than on  the other Zeros, and they really don't break that often. I put a poll here to find out for myself, see here. (http://electricmotorcycleforum.com/boards/index.php?topic=9022.msg77755#msg77755)

I have around 7,000 miles on each of my Zeros and no belt problems yet (as I knock on wood).

-Don-  Auburn, CA



Title: Re: SR/F belt breaks on test ride video. Has anyone else broken an SR/F belt?
Post by: ESokoloff on August 12, 2019, 09:14:43 AM
This video kind of spooked me. ..........
The worrying part was that he was on a flat and level road, not jumping curbs or hitting a pothole. ..........

I watched the video & saw that the road was quite bumpy.
How many times was that poor belt subjected to that rough road/strong exceleration combo?

I'm not saying that the belt design is not faulty, just trying to play devils advocate.
Title: Re: SR/F belt breaks on test ride video. Has anyone else broken an SR/F belt?
Post by: NEW2elec on August 12, 2019, 10:05:35 AM
I'm starting to wonder if a spring loaded dampening belt tensioner pulley added with a larger belt to absorb some of the stress of take off and pothole free spin and reload is needed.
Title: Re: SR/F belt breaks on test ride video. Has anyone else broken an SR/F belt?
Post by: Shadow on August 12, 2019, 10:08:04 AM
That silly sounding pop and whir when the belt snaps made me chuckle a good bit...  ;D   Anytime I've shredded through a DSR belt it sounded more like angry godzilla.

Rotational mass on the SR/F drive wheel is quite a bit more (at a guess?) from S/DS.

Wild conjecture: The motor drive logic really ought to have some kind of feedback loop with the ABS sensor so we're smoothly applying the desired torque within limits the belt can withstand.

Also see above written while I was posting. Mechanical or electronic, something has got to give?
Title: Re: SR/F belt breaks on test ride video. Has anyone else broken an SR/F belt?
Post by: DonTom on August 12, 2019, 10:10:03 AM
This video kind of spooked me. ..........
The worrying part was that he was on a flat and level road, not jumping curbs or hitting a pothole. ..........

I watched the video & saw that the road was quite bumpy.
How many times was that poor belt subjected to that rough road/strong exceleration combo?

I'm not saying that the belt design is not faulty, just trying to play devils advocate.
I would think traction control would solve the problem of bumps. If the rear wheel  spins freely (faster than the front), the motor should stop for that instant, releasing any belt tension.

-Don-  Auburn, CA
Title: Re: SR/F belt breaks on test ride video. Has anyone else broken an SR/F belt?
Post by: JasonHC on August 12, 2019, 10:28:14 AM
The fix is painfully easy.

Pontiac sold a million Grand Prix's with the slogan.

Instead of a 17mm itty bitty baby belt.

How about a nice wide one like any Indian or HD has.
22mm is about as small as they use, 25mm is very common, I think 38mm is the most commonly used size now, and there are millions of them on the road, and it's VERY rare for them to "snap" or "pop" off.

Wider is Better!

YES, ZERO designed the swingarm with no room for a wider belt. That was just dumb.

Honestly, I expect a complete recall for every SR/F. Since there is just no space for a wider belt, do just like the FX did, and put a chain on it.


Title: Re: SR/F belt breaks on test ride video. Has anyone else broken an SR/F belt?
Post by: Moto7575 on August 12, 2019, 04:53:46 PM
A friend broke a belt twice in a row with a Zero S. The problem was the dealers mistake (excessive tension on the belt). That might have been the case for the S/R you bought.
Title: Re: SR/F belt breaks on test ride video. Has anyone else broken an SR/F belt?
Post by: stevenh on August 12, 2019, 05:01:14 PM
A friend broke a belt twice in a row with a Zero S. The problem was the dealers mistake (excessive tension on the belt). That might have been the case for the S/R you bought.

When I took delivery on my DSR in 2016, the belt was WAY over tight, I think this was common for a while (several of us had to decrease the tension after taking delivery around that time).  Once adjusted to the lower side of the specification, the belt lasted fine for over 10K miles, and 3.5 years.

Steve
Title: Re: SR/F belt breaks on test ride video. Has anyone else broken an SR/F belt?
Post by: alko on August 12, 2019, 06:23:13 PM
I'm starting to wonder if a spring loaded dampening belt tensioner pulley added with a larger belt to absorb some of the stress of take off and pothole free spin and reload is needed.

I've wondered the exact same thing. A tensioner pulley would be a great improvement!
Title: Re: SR/F belt breaks on test ride video. Has anyone else broken an SR/F belt?
Post by: Richard230 on August 12, 2019, 07:58:59 PM
Don't forget that the motor sprocket is concentric with the swingarm pivot. That should prevent any changes in belt tension as the swingarm moves up and down. So I am not sure if a spring tensioner is going to help much while riding over a bumpy surface.  ??? Also, don't forget that there have been a lot of DR Zeros riding around on very bumpy off-road tracks over the years and I can't recall anyone ever mentioning that they were stranded in the boondocks due to a broken belt.  So my guess is that belts are most likely to break due to over tightening, incorrect alignment, or environmental damage (rocks, chemicals like road salt, etc.) - all of which can be checked and corrected by the owner.
Title: Re: SR/F belt breaks on test ride video. Has anyone else broken an SR/F belt?
Post by: alko on August 12, 2019, 08:10:48 PM
Don't forget that the motor sprocket is concentric with the swingarm pivot. That should prevent any changes in belt tension as the swingarm moves up and down. So I am not sure if a spring tensioner is going to help much while riding over a bumpy surface.  ??? Also, don't forget that there have been a lot of DR Zeros riding around on very bumpy off-road tracks over the years and I can't recall anyone ever mentioning that they were stranded in the boondocks due to a broken belt.  So my guess is that belts are most likely to break due to over tightening, incorrect alignment, or environmental damage (rocks, chemicals like road salt, etc.) - all of which can be checked and corrected by the owner.

I disagree with your assumption that belt tension doesn't change with movement of the swingarm. Under heavy acceleration, sharp bumps and potholes can hugely increase stress on the belt. Whether it's enough to snap a belt, It's probably a combination of other factors as well, but under the right conditions it can happen. A belt tensioner would prevent it even if it's a rock, twig stuck in the belt.
Title: Re: SR/F belt breaks on test ride video. Has anyone else broken an SR/F belt?
Post by: NoMoreIdeas on August 12, 2019, 08:25:12 PM
This could have been a lot of things that werent Zero's fault. Overtightened belt, mis-alligned rear wheel or just a faulty belt. Its the dealers responsibility to go over the bike between the time its taken out of the crate and into a customer's hands. In my experience, my zero was delivered with a mis-alligned wheel which created an awful noise for quite some time before I figured it out.
Title: Re: SR/F belt breaks on test ride video. Has anyone else broken an SR/F belt?
Post by: DonTom on August 12, 2019, 08:33:36 PM
This could have been a lot of things that werent Zero's fault. Overtightened belt, mis-alligned rear wheel or just a faulty belt. Its the dealers responsibility to go over the bike between the time its taken out of the crate and into a customer's hands. In my experience, my zero was delivered with a mis-alligned wheel which created an awful noise for quite some time before I figured it out.
I have noticed on my 2017s, that Zero over-tightens everything. Nothing near their own suggested torque values.

-Don-  Auburn, CA
Title: Re: SR/F belt breaks on test ride video. Has anyone else broken an SR/F belt?
Post by: NEW2elec on August 12, 2019, 09:01:05 PM
 A few tests meant to snap the belt under a spin up and wheel stop under load while filmed with a slow motion camera to confirm where the belt snaps would be needed.
For now I'll assume it's at the top near the rear sprocket.  That seems to be the point where the sprocket is no longer holding the belt's teeth in place and so that part of the belt is under the most stress while the motor pulley is still spinning and a point where the belt can stretch and break.
A tensioner pulley would attach to the swing arm in my mind.  The belt would have a larger circumference and the added slack would be taken up be the tensioner pulley at the (assumed) weakest point.  As the added tension of a spin up and reload happens the belt would pull against the pulley and the extra slack would be used as a cushion until the pulley rebounded and takes the slack back out of the belt line.

Could the correct spring tension be found that works with the set up?  That's the hard part.

As it is now I would think that "this" bike's problem is likely having the belt at the wrong tension to start with but if a tensioner pulley could work it gives you a greater margin of error.
Title: Re: SR/F belt breaks on test ride video. Has anyone else broken an SR/F belt?
Post by: vinceherman on August 12, 2019, 09:14:28 PM
I see that the unofficial manual has a procedure for replacing the belt on other platforms.
Has anyone done a belt replacement on the SR/F?
What was the general process?  What tools were needed?
I like the idea of having a spare belt.  I assume I need to order that through the dealer?
Title: Re: SR/F belt breaks on test ride video. Has anyone else broken an SR/F belt?
Post by: DonTom on August 12, 2019, 09:20:27 PM
I see that the unofficial manual has a procedure for replacing the belt on other platforms.
Has anyone done a belt replacement on the SR/F?
What was the general process?  What tools were needed?
I like the idea of having a spare belt.  I assume I need to order that through the dealer?

AF1 racing. (https://www.af1racing.com/store/Scripts/prodView.asp?idproduct=97906&sku=ZM30-08226&description=OEM+Zero+Drive+Belt+151+Teeth+%2D+ZM30%2D08226)

-Don-  Auburn, CA
Title: Re: SR/F belt breaks on test ride video. Has anyone else broken an SR/F belt?
Post by: DonTom on August 12, 2019, 09:26:31 PM
I see that the unofficial manual has a procedure for replacing the belt on other platforms.
Has anyone done a belt replacement on the SR/F?
What was the general process?  What tools were needed?
I like the idea of having a spare belt.  I assume I need to order that through the dealer?
By looking at the SR/F, it looks like it is a lot easier to replace the belt, as there is plenty of room near the swing arm.  I think all that needs to be done is to remove the rear wheel and slip on a new belt and then do the adjustments. 

I am going by what I saw when I did my test ride on the SR/F.  That was one of the things I checked and it looked very easy compared to ALL older Zero models.

-Don-  Auburn, CA
Title: Re: SR/F belt breaks on test ride video. Has anyone else broken an SR/F belt?
Post by: ESokoloff on August 12, 2019, 11:00:45 PM
Don't forget that the motor sprocket is concentric with the swingarm pivot. That should prevent any changes in belt tension as the swingarm moves up and down. ............

I’m thinking that it’s quite the opposite in that belt tension does vary with swing arm travel.

Under power/acceleration the motor pulls pulls the belt on the top half & pushes on the bottom half so upon compression of shock, belt tension decreases & upon rebound it increases (top half of belt).

I’m betting that most of the miles on that belt were subjected to that bumpy road & it took its toll on that belt.
Other factors may apply but likely  this was a major factor.



 
Title: Re: SR/F belt breaks on test ride video. Has anyone else broken an SR/F belt?
Post by: Jarrett on August 13, 2019, 04:10:39 AM
That silly sounding pop and whir when the belt snaps made me chuckle a good bit...  ;D   
It was almost cartoonish, lol.
Title: Re: SR/F belt breaks on test ride video. Has anyone else broken an SR/F belt?
Post by: Say10 15FX 16FXS on August 13, 2019, 04:33:36 AM
It looks like you can see the front pulley which means you may be able to replace the belt without removing the swing arm. On the previous models the swing arm has to be removed to get the belt on. If you only have to remove that goofy thingy on the back wheel, a belt change would be simple.
Title: Re: SR/F belt breaks on test ride video. Has anyone else broken an SR/F belt?
Post by: alko on August 13, 2019, 04:52:36 AM
It looks like you can see the front pulley which means you may be able to replace the belt without removing the swing arm. On the previous models the swing arm has to be removed to get the belt on. If you only have to remove that goofy thingy on the back wheel, a belt change would be simple.

Still have to remove wheel at the very least, so not something you can do on the side of the road unfortunately.
Title: Re: SR/F belt breaks on test ride video. Has anyone else broken an SR/F belt?
Post by: Bill822 on August 13, 2019, 05:20:18 AM
It looks like you can see the front pulley which means you may be able to replace the belt without removing the swing arm. On the previous models the swing arm has to be removed to get the belt on. If you only have to remove that goofy thingy on the back wheel, a belt change would be simple.

Still have to remove wheel at the very least, so not something you can do on the side of the road unfortunately.

I don't see how taking the wheel off would be helpful at all. License plate holder thing only attached on one side. One belt guard bolt must come out but otherwise just loosen the rear wheel adjustment. Very roadside-friendly job (that i never want to do on a roadside)
Title: Re: SR/F belt breaks on test ride video. Has anyone else broken an SR/F belt?
Post by: vinceherman on August 13, 2019, 06:14:37 AM
Just guessing, since I have not done any disassembly, but it looks to me like the wiring harness going to the license plate is also in the way.  I assume it unplugs somewhere back there.  Clip some zip ties.  Unbolt the guard.  Then slide the belt around the possum scraper and it has a clear path to the sprocket.
Again, guessing.
And I do not know what is involved in bringing the wheel forward far enough to allow installation on both pulleys now what is involved in setting the tension after.
But hey, I bought a pack of the flat zip ties so I have that covered!
Title: Re: SR/F belt breaks on test ride video. Has anyone else broken an SR/F belt?
Post by: alko on August 13, 2019, 06:23:43 AM
It looks like you can see the front pulley which means you may be able to replace the belt without removing the swing arm. On the previous models the swing arm has to be removed to get the belt on. If you only have to remove that goofy thingy on the back wheel, a belt change would be simple.

Still have to remove wheel at the very least, so not something you can do on the side of the road unfortunately.

I don't see how taking the wheel off would be helpful at all. License plate holder thing only attached on one side. One belt guard bolt must come out but otherwise just loosen the rear wheel adjustment. Very roadside-friendly job (that i never want to do on a roadside)

You may not have to remove swingarm like you do on previous models, but you still have to remove the wheel.
Title: Re: SR/F belt breaks on test ride video. Has anyone else broken an SR/F belt?
Post by: Bill822 on August 13, 2019, 02:03:53 PM
quote author=alko link=topic=9275.msg81126#msg81126 date=1565655823

Still have to remove wheel at the very least, so not something you can do on the side of the road unfortunately.


Nope. I actually have one. It looks dead simple. The mud guard/license thingie is only attached on one side, Ducati style. Loosen the adjuster, remove the near side chain fastener. Should be able to slide the belt under the chain guard/fender thing. If not, weak hands perhaps, then loosen the other side too. Belt should pop right on. The most difficult part will be swallowing the near $200 price of the belt.  Photos in link.

EDIT: Forgot to mention the wire. Comes loose when you unbolt the chain guard. Has slack. Just tuck the belt through. Also formatting is FUBAR

EDIT2: OK, wrong about the wire. Must be a plug for it to unhook but it is way late and I don't want to go back out in the garage. I'll look at it tomorrow. Even unlacing the whole swingarm harness would only be a 5 minute job, held on by clips, but there must be a plug on it somewhere. If not, there will be :)


https://imgur.com/a/J62rKYc (https://imgur.com/a/J62rKYc)
Title: Re: SR/F belt breaks on test ride video. Has anyone else broken an SR/F belt?
Post by: Richard230 on August 13, 2019, 07:41:28 PM
I first experienced that rear tire mudguard thingie when I bought a 1997 BMW F650 "Funduro".  At that time the claim was that the German TUV required it to prevent road slop from being flung up into the air and on to following vehicles and it was in-lieu of having a larger rear fender. The one on the Funduro didn't have a license plate or tail light attached.  The first thing most of us Funduro owners did was to remove the entire device, which we called a "possum scraper", as we thought it was not very stylish and interfered with wheel removal somewhat - and besides, most of the vehicles following us would have windshield wipers.   ;)
Title: Re: SR/F belt breaks on test ride video. Has anyone else broken an SR/F belt?
Post by: alko on August 13, 2019, 07:42:50 PM
quote author=alko link=topic=9275.msg81126#msg81126 date=1565655823

Still have to remove wheel at the very least, so not something you can do on the side of the road unfortunately.


Nope. I actually have one. It looks dead simple. The mud guard/license thingie is only attached on one side, Ducati style. Loosen the adjuster, remove the near side chain fastener. Should be able to slide the belt under the chain guard/fender thing. If not, weak hands perhaps, then loosen the other side too. Belt should pop right on. The most difficult part will be swallowing the near $200 price of the belt.  Photos in link.

EDIT: Forgot to mention the wire. Comes loose when you unbolt the chain guard. Has slack. Just tuck the belt through. Also formatting is FUBAR

EDIT2: OK, wrong about the wire. Must be a plug for it to unhook but it is way late and I don't want to go back out in the garage. I'll look at it tomorrow. Even unlacing the whole swingarm harness would only be a 5 minute job, held on by clips, but there must be a plug on it somewhere. If not, there will be :)


https://imgur.com/a/J62rKYc (https://imgur.com/a/J62rKYc)

Unless the swingarm pivot floats in midair, there's no way you can put the belt over both pulleys without removing the rear wheel.
However, a single-sided swingarm with the belt on the opposite side would be a sweet design and make belt swap a piece of cake.
Title: Re: SR/F belt breaks on test ride video. Has anyone else broken an SR/F belt?
Post by: Bill822 on August 14, 2019, 01:23:04 AM
quote author=alko link=topic=9275.msg81126#msg81126 date=1565655823

Still have to remove wheel at the very least, so not something you can do on the side of the road unfortunately.


Nope. I actually have one. It looks dead simple. The mud guard/license thingie is only attached on one side, Ducati style. Loosen the adjuster, remove the near side chain fastener. Should be able to slide the belt under the chain guard/fender thing. If not, weak hands perhaps, then loosen the other side too. Belt should pop right on. The most difficult part will be swallowing the near $200 price of the belt.  Photos in link.

EDIT: Forgot to mention the wire. Comes loose when you unbolt the chain guard. Has slack. Just tuck the belt through. Also formatting is FUBAR

EDIT2: OK, wrong about the wire. Must be a plug for it to unhook but it is way late and I don't want to go back out in the garage. I'll look at it tomorrow. Even unlacing the whole swingarm harness would only be a 5 minute job, held on by clips, but there must be a plug on it somewhere. If not, there will be :)


https://imgur.com/a/J62rKYc (https://imgur.com/a/J62rKYc)

Unless the swingarm pivot floats in midair, there's no way you can put the belt over both pulleys without removing the rear wheel.
However, a single-sided swingarm with the belt on the opposite side would be a sweet design and make belt swap a piece of cake.

Look at the top photo in the link above or look at an actual SR/F. The swingarm is a non-issue, not in the path of the belt in any way. The motor is the swingarm pivot on an SR/F.

While I do enjoy chatting with "forum experts" I think I'm through with this conversation.
Title: Re: SR/F belt breaks on test ride video. Has anyone else broken an SR/F belt?
Post by: alko on August 14, 2019, 03:02:09 AM
quote author=alko link=topic=9275.msg81126#msg81126 date=1565655823

Still have to remove wheel at the very least, so not something you can do on the side of the road unfortunately.


Nope. I actually have one. It looks dead simple. The mud guard/license thingie is only attached on one side, Ducati style. Loosen the adjuster, remove the near side chain fastener. Should be able to slide the belt under the chain guard/fender thing. If not, weak hands perhaps, then loosen the other side too. Belt should pop right on. The most difficult part will be swallowing the near $200 price of the belt.  Photos in link.

EDIT: Forgot to mention the wire. Comes loose when you unbolt the chain guard. Has slack. Just tuck the belt through. Also formatting is FUBAR

EDIT2: OK, wrong about the wire. Must be a plug for it to unhook but it is way late and I don't want to go back out in the garage. I'll look at it tomorrow. Even unlacing the whole swingarm harness would only be a 5 minute job, held on by clips, but there must be a plug on it somewhere. If not, there will be :)


https://imgur.com/a/J62rKYc (https://imgur.com/a/J62rKYc)

Unless the swingarm pivot floats in midair, there's no way you can put the belt over both pulleys without removing the rear wheel.
However, a single-sided swingarm with the belt on the opposite side would be a sweet design and make belt swap a piece of cake.

Look at the top photo in the link above or look at an actual SR/F. The swingarm is a non-issue, not in the path of the belt in any way. The motor is the swingarm pivot on an SR/F.

While I do enjoy chatting with "forum experts" I think I'm through with this conversation.

My mistake! Sorry. And thanks for the photo. I've looked all over the internet for a picture like that. Good job Zero!
Title: Re: SR/F belt breaks on test ride video. Has anyone else broken an SR/F belt?
Post by: GS-A-Day on August 14, 2019, 06:48:38 AM
This video kind of spooked me. Has anyone else broken an SR/F belt or even heard of one breaking?
The worrying part was that he was on a flat and level road, not jumping curbs or hitting a pothole. Start carrying a spare belt? Maybe so.

https://www.youtube.com/watch?v=fOMwuhotyng

The exact same thing happened to me on a test drive. The belt even broke in the same way.
Title: Re: SR/F belt breaks on test ride video. Has anyone else broken an SR/F belt?
Post by: heroto on August 14, 2019, 09:25:30 AM
Replacement belt price online in the US is $140. This thread just sold a "just in case" back up belt.
These belts should break pretty much never. Something is not quite right in Zeroland.