Rattle that seems to be coming from my cvt

I bought a 2013 swing a year or so ago, and it's been fine for all riding. freeway, casual, and gravel. lately, on acceleration, i'm getting a rattle that seems to be coming from my cvt.

got 10,300 or so on the clock. is this a regular maintenance issue, or something else?

i'm hoping sliders in the variator, but i know belt change is coming soon. is this common, or horrifying?

Thanks!
edit: rpms seeem a little high on the freeway, but not redlining/

Just run engine up against brakes---10/15 seconds. Leave alone and ride---change belt with OEM part at 15,000 miles. Leave rest of driveline stock This based on near 100,000 miles with 2 new Silverwings, and never walked....always remembering it is scooter.

Would that be “almost… but not quite” redlining? What are your rpms at cruising speeds? When does this rattle occur… is it continual, intermittent? Does it happen if you are accelerating from freeway cruising to pass the vehicle ahead then cease when you return to cruising?

You mentioned that you commute “the worlds largest freeway”. If you constantly ride aggressively, at 10,000 miles the belt could be worn & stretched to the point that it’s slapping the belt case. At any rate the belt, variator, and rollers should be checked and all the belt dust cleaned out.

Remember, too---bike is not new, early change of belt might be good idea also.

Cosmic_Jumper wrote:

Would that be “almost… but not quite” redlining? What are your rpms at cruising speeds? When does this rattle occur… is it continual, intermittent? Does it happen if you are accelerating from freeway cruising to pass the vehicle ahead then cease when you return to cruising?

You mentioned that you commute “the worlds largest freeway”. If you constantly ride aggressively, at 10,000 miles the belt could be worn & stretched to the point that it’s slapping the belt case. At any rate the belt, variator, and rollers should be checked and all the belt dust cleaned out.

at freeway speeds (65-70 mph) i'm at 5.5-6k rpms. the rattling seems to happen with shifting, which is why i was thinking a cvt issue. happens almost immediately on startup, then occasionally right before rpms drop (at shift). i do ride somewhat aggressively, but not like it's a sport bike or anything, just a lot of freeway riding for work commute.

At that speed those revs sound about right.
You mention the rattle happens when shifting, but it's a CVT so shifts all the time not in blocks like a regular gearbox (auto or manual). Do you mean it rattles when first setting off?
If you're reasonably confident with a set of tools I would suggest having a look in there. It's not difficult, just take your time and reference the service manual and U-tube as necessary.
There is always the risk the previous owner has been in there and not torqued something up - there are still gorillas out there who think they can torque things up by feel.
If you take it to a regular bike garage it might be their first time working on a CVT too.

Kunamika, one of the benefits of disclosing your general location (i.e. you don't need to be address or even city/town specific), is that there may be another more seasoned site member close by willing to take a look and listen to your ride.  

Some even help others by teaching them how to perform basic routine maintenance like oil, air and belt changes etc.

Just a thought, may it be just loose body panel (s) , harmonic vibration?

oldwingguy wrote:

Just a thought, may it be just loose body panel (s) , harmonic vibration?

i thought it might be that, at first. maybe loose heat shield. after checking panels and shield, cleaning out the case, i think it's belt slapping or the cvt shoes. cleaning out the case definitely lessened the frequency, but it still seems to happen when rpms drop during acceleration.

I know people on here have pointed out cvt is continuous shifting, but it seems like there are definite points where rpms drop, so idk.

regardless, seems to be nothing major. got a bit paranoid as i'm planning my first 500+ mile ride.

steve_h80 wrote:

At that speed those revs sound about right.
You mention the rattle happens when shifting, but it's a CVT so shifts all the time not in blocks like a regular gearbox (auto or manual). Do you mean it rattles when first setting off?
If you're reasonably confident with a set of tools I would suggest having a look in there. It's not difficult, just take your time and reference the service manual and U-tube as necessary.
There is always the risk the previous owner has been in there and not torqued something up - there are still gorillas out there who think they can torque things up by feel.
If you take it to a regular bike garage it might be their first time working on a CVT too.

thanks, steve!

it happens during rpm drops while accelerating, so i just assumed it was during major shifts. idk if there's another term for rpm drops in a cvt, or reason for it. I appreciate the insight!

I'm no expert, but i'm comfortable with my tools (was an engineman in the navy), and i like doing the work. Cleaned out the case, and it appears to be either belt slap (belt was still in good condition) or cvt shoes.

Cosmic_Jumper wrote:

Would that be “almost… but not quite” redlining? What are your rpms at cruising speeds? When does this rattle occur… is it continual, intermittent? Does it happen if you are accelerating from freeway cruising to pass the vehicle ahead then cease when you return to cruising?

You mentioned that you commute “the worlds largest freeway”. If you constantly ride aggressively, at 10,000 miles the belt could be worn & stretched to the point that it’s slapping the belt case. At any rate the belt, variator, and rollers should be checked and all the belt dust cleaned out.

Thanks jumper. i think it might be slapping. Should i go ahead and replace the belt? it didn't look too worn, and the case wasn't too dusty. bit or powdered rubber, but not much at all. if slapping means it's time to switch though, i'd be enthused to avert potential issues.

I appreciate all the seasoned help for a greenhorn!

I'd say no to replacing the belt at this point.  With only 10k miles on it, it should have decent life left in it.

You could measure it to ensure it is within spec though.  Off the top of my head, service spec is 28mm and not recommended to fall below 27mm.  If you use the "search" function, I know there are some detailed threads about the spec and how to properly measure for it as there is a bit of a trick to it IIRC.

sonuvabug wrote:

I'd say no to replacing the belt at this point.  With only 10k miles on it, it should have decent life left in it.

I know there are some detailed threads about the spec and how to properly measure for it as there is a bit of a trick to it IIRC.

Thanks for the tip on finding the trick! There's always some sort of trick to it, imo. Still amazed when i try the "trick" to change tires, and spend 3 hours with no luck, just to spend $15 at a used tire shop and get it done in as many minutes.

I'll probably replace the belt in the next thousand miles or so, anyway. putting 5-600 miles on a week, so i might as well be ahead of the curve

Kunamika Hopper wrote:

Cosmic_Jumper wrote:

Would that be “almost… but not quite” redlining? What are your rpms at cruising speeds? When does this rattle occur… is it continual, intermittent? Does it happen if you are accelerating from freeway cruising to pass the vehicle ahead then cease when you return to cruising?

You mentioned that you commute “the worlds largest freeway”. If you constantly ride aggressively, at 10,000 miles the belt could be worn & stretched to the point that it’s slapping the belt case. At any rate the belt, variator, and rollers should be checked and all the belt dust cleaned out.

Thanks jumper. i think it might be slapping. Should i go ahead and replace the belt? it didn't look too worn, and the case wasn't too dusty. bit or powdered rubber, but not much at all. if slapping means it's time to switch though, i'd be enthused to avert potential issues.

I appreciate all the seasoned help for a greenhorn!

Did the belt case have nicely polished area where the belt touched the case?

Have a look on youtube. There's several videos on there showing belt replacement and even with a new belt fitted it can still slap around in the drive case https://www.youtube.com/watch?v=WUcLb7nfJIs&t=539s

oldwingguy wrote:

Kunamika Hopper wrote:

Cosmic_Jumper wrote:

Would that be “almost… but not quite” redlining? What are your rpms at cruising speeds? When does this rattle occur… is it continual, intermittent? Does it happen if you are accelerating from freeway cruising to pass the vehicle ahead then cease when you return to cruising?

You mentioned that you commute “the worlds largest freeway”. If you constantly ride aggressively, at 10,000 miles the belt could be worn & stretched to the point that it’s slapping the belt case. At any rate the belt, variator, and rollers should be checked and all the belt dust cleaned out.

Thanks jumper. i think it might be slapping. Should i go ahead and replace the belt? it didn't look too worn, and the case wasn't too dusty. bit or powdered rubber, but not much at all. if slapping means it's time to switch though, i'd be enthused to avert potential issues.

I appreciate all the seasoned help for a greenhorn!

 Did the belt case have nicely polished area where the belt touched the case?

you know, i didn't check. i'll open her up again tomorrow before work and see. probably would have been easier pre-cleaning, but you don't to look till you know.

Thanks!

terrier wrote:

Have a look on youtube. There's several videos on there showing belt replacement and even with a new belt fitted it can still slap around in the drive case  https://www.youtube.com/watch?v=WUcLb7nfJIs&t=539s

I appreciate it! I've done belt replacements before on a chi 150. like a dummy, i thought enough work would keep that thing running forever lol. I've watched a few videos on silverwing specific replacement. MSG motovlogs, several times. I'll check out the video you sent though.

try putting it up on the centre stand and run up the motor as you might find the resonances associated with your observation. This can show up problem with unbalanced rear tire and also be able to pinpoint the tupperware rattle. make sure you are on concrete and have your hands on the brakes. worked for me in the past.

Check your bulbs access cover in underseat compartments for rattle, black duct taped mine  

 Just several random points/opinions on CVT's.

 One of the most important and also neglected services on scooters CVT/Tansmissions is the cvt air filter and cvt cavity inspection/cleaning, blowing dust out, etc. The air filter is a 4k miles service item, neglecting it can really impact cooling air flow to cvt components and moving contaminants out, components will overheat, especially the belt !!, dust generated by normal clutch and belt wear will accumulate/build up in components. like variator rollers and ramps, causing binding/flat spots/"Vibrations". 

I do mine yearly and/or at every oil change(5k miles).

 The takeaway is, if the P/O neglected these services and your filter is very dirty/clogged, it really affects the service life of belt, etc. I worked on lot's of scooters and aprox 95% had this issue, I usually "recommend" a belt change, regardless of visual condition or measurements, you really cannot see or gage "Heat Damage" on a rubber belt, if I see any "Purple/Blue" discoloration on clutch bell(excess of 550F/300C)I recommend a full tear down inspect/service, temps well beyond most seals and grease normal operating range !!

 The SW600 has very robust cvt components, but still uses a mostly "made out of rubber" belt, I truly believe the oem belt mileage change interval is very conservative, but it's also flawed IMO as it should also have a "Age" change interval as well, for comparison most car "Timing Belts" will go 100K miles, but most have a 6-10 year change interval, regardles(irregardless??) of mileage.

 BTW most of those You Tube DIY belt videos shows them tightening the front variator bolt with impact while jamming the belt between pulleys and turning engine backwards or using starter, etc.,dangerous/very wrong !!, check this video at 3:15 - 4:30, yes is a B400, but same idea, do until bolt stops, is best to wear gloves.

https://youtu.be/oQczm1IPLv4

Very good info. zrx212 Never turn a timing chain engine backwards chain can and will jump then things get ugly. Proper holding tools and torque wrenches are the best way to replace the belt.

zrx212 wrote:

Check your bulbs access cover in underseat compartments for rattle, black duct taped mine  

 Just several random points/opinions on CVT's.

 One of the most important and also neglected services on scooters CVT/Tansmissions is the cvt air filter and cvt cavity inspection/cleaning, blowing dust out, etc. The air filter is a 4k miles service item, neglecting it can really impact cooling air flow to cvt components and moving contaminants out, components will overheat, especially the belt !!, dust generated by normal clutch and belt wear will accumulate/build up in components. like variator rollers and ramps, causing binding/flat spots/"Vibrations". 

I do mine yearly and/or at every oil change(5k miles).

 The takeaway is, if the P/O neglected these services and your filter is very dirty/clogged, it really affects the service life of belt, etc. I worked on lot's of scooters and aprox 95% had this issue, I usually "recommend" a belt change, regardless of visual condition or measurements, you really cannot see or gage "Heat Damage" on a rubber belt, if I see any "Purple/Blue" discoloration on clutch bell(excess of 550F/300C)I recommend a full tear down inspect/service, temps well beyond most seals and grease normal operating range !!

 The SW600 has very robust cvt components, but still uses a mostly "made out of rubber" belt, I truly believe the oem belt mileage change interval is very conservative, but it's also flawed IMO as it should also have a "Age" change interval as well, for comparison most car "Timing Belts" will go 100K miles, but most have a 6-10 year change interval, regardles(irregardless??) of mileage.

 BTW most of those You Tube DIY belt videos shows them tightening the front variator bolt with impact while jamming the belt between pulleys and turning engine backwards or using starter, etc.,dangerous/very wrong !!, check this video at 3:15 - 4:30, yes is a B400, but same idea, do until bolt stops, is best to wear gloves.

https://youtu.be/oQczm1IPLv4

This is all really good info. I had not considered progressive heat damage. I am coming up on a filter change, however, i haven't looked into the process. do i need to buy a new filter, or is there a cleaning method?
Thank you for the info!

You can clean the CVT air filter, providing it doesn't fall apart in your hand as mine did. I bought a piece of open cell foam at a fabric shop and cut it to fit, works nicely.

I wash mine in some warm, slightly soapy water. Let it soak and give a 'squish' or two. Rinse it and make sure it dries thoroughly.

However, next time I'm going to use a drop of motorcycle cleaner in the water. I use 'MucOff' to clean the bike so I figured it will do no harm to the sponge/filter.

Just my ten-bobs worth!

BTW KunamikaHopper, I'd like to PM you so watch out for the 'blinking' PM icon at the top of the home page.

oldwingguy wrote:

You can clean the CVT air filter, providing it  doesn't fall apart in your hand as mine did. I bought a piece of open cell foam at a fabric shop and cut it to fit, works nicely.

 

 I did similar mod to mine, bu I'm going to install stainless steel screen mesh on oem filter frame, whenever I get around to it ...