Strange sound/vibration @ 5200 rpm

4435 Views 23 Replies 11 Participants Last post by Brockie, 7 mo ago

shinobigami

Discussion Starter · 8 mo ago

I have a strange sound/vibration happening at exactly 5200 rpm, only when in gear, but in every gear. I usually switch gears well before 5k rpm so I didn’t really notice and have no idea how long it’s been going on. When in neutral revved to 5200 rpm, no unusual sound/vibration, but when in gear @ 5200 rpm, there’s a high pitched vibration sound. I do not feel the vibration but can definitely hear it. Say I’m in 6th gear on the highway 5200rpm, about 72mph on my dash, if I keep her steady the sound is constant, in any gear at that specific rpm, but any faster or slower and it quickly goes away. Any input is greatly appreciated. 🙏

The first video you can hear the sound (blip) at 5200 rpm as I’m switching gears 1-5 past that range, as I’m on the on-ramp to the highway. Then in 6th on the highway I’m coasting in that +/- 5k range:

In the second, I’m going through a tunnel so I thought maybe I’d catch better sound, in 5th gear: Strange noise at 5200 rpm ‘21 v strom

These were taken with my phone while mounted on the bike (if you use earphones the sound is much clearer) but I’m going to see if my go pro will catch better sound.

1 - 20 of 24 Posts

jimpeter

· #2 · 8 mo ago

If you have Givi crash bars fitted, check the joint in front of the exhaust pipe, there are some O-rings in the joint that have broken.

Reactions: 4

Motorpsychology

· #3 · 8 mo ago

jimpeter said:
If you have Givi crash bars fitted, check the joint in front of the exhaust pipe, there are some O-rings in the joint that have broken.

If you have a stock windshield Check the hex bolts I had an odd buzzing at about that rpm, thought it was behind the instrument cluster. When I went to remove the shield, two of the bolts were loose.

Reactions: 1

vanseagal

· #4 · 8 mo ago

These bikes tend to have a sweet spot for vibration around those rpms. Try to ride with the sound on and touch with your left hand mirrors, levers etc. I once had that kind of sound and it was keyring. It stopped when I touched it.

Reactions: 2

shinobigami

Discussion Starter · #5 · 8 mo ago

jimpeter said:
If you have Givi crash bars fitted, check the joint in front of the exhaust pipe, there are some O-rings in the joint that have broken.

I do have Givi crash bars installed and just checked the o rings, they’re intact and not broken. I’m wondering if I should replace them with some electrical tape.

shinobigami

Discussion Starter · #6 · 8 mo ago

Motorpsychology said:
If you have a stock windshield Check the hex bolts I had an odd buzzing at about that rpm, thought it was behind the instrument cluster. When I went to remove the shield, two of the bolts were loose.

I have an adjustable Givi airflow windshield installed, but will try holding it while at that rpm to see if it is the windshield.

shinobigami

Discussion Starter · #7 · 8 mo ago

vanseagal said:
These bikes tend to have a sweet spot for vibration around those rpms. Try to ride with the sound on and touch with your left hand mirrors, levers etc. I once had that kind of sound and it was keyring. It stopped when I touched it.

Will do, thanks for the tip, I feel the sound is coming from somewhere I can’t reach while riding though.😩

dmfdmf

· #8 · 8 mo ago

I usually switch gears well before 5k rpm so I didn’t really notice

All the fun begins around 7K RPM, you are missing out ;-)

I had a Gen2/2014 Wee that had vibration right around that point and the Givi crash bars would buzz. My Gen1B/2007 Wee did not have that "feature". I'd temporarily remove the crash bars and go for a spin as a test. I think the 5200 vibration is inherent in the Gladius motors and something on the bike is resonating in sympathy with the motor at that RPM.

As others suggested, I revamped the cross-over connector on the crash bars which stopped the buzz but I could still feel the vibration when crossing 5200 RPM. I found that one of my lower throttle body boots was loose which was causing power imbalance between the cylinders making the vibes worse. I reseated and retorqued the motor mount in the frame cradle which also helped to get the vibes down to an acceptable level.

See less See more

Reactions: 1

Eric1980

· #9 · 8 mo ago

I don't see how any of the potential suggestions above explain why the noise only occurs when the bike is in gear. E.g. If the crash bars resonate when the engine is at 5200 RPM, it should also resonate with the bike stopped and in neutral.

If it really is only occurring when the bike is in gear, perhaps it has something to do with the chain? Maybe if the tension was too loose it could vibrate against something at a certain RPM? Or perhaps something do so with the transmission itself? I don't know.

shinobigami

Discussion Starter · #10 · 8 mo ago

Eric1980 said:
I don't see how any of the potential suggestions above explain why the noise only occurs when the bike is in gear. E.g. If the crash bars resonate when the engine is at 5200 RPM, it should also resonate with the bike stopped and in neutral.

If it really is only occurring when the bike is in gear, perhaps it has something to do with the chain? Maybe if the tension was too loose it could vibrate against something at a certain RPM? Or perhaps something do so with the transmission itself? I don't know.

It is only when in gear, but there’s definitely a difference in feel/vibration when the bike is in neutral vs in gear at any rpm range for any engine. In neutral the vibes are “clearer” and with the transmission engaged you can definitely feel the added strain. God I hope it’s not the transmission itself 🤦‍♂️

shinobigami

Discussion Starter · #11 · 8 mo ago

dmfdmf said:
All the fun begins around 7K RPM, you are missing out ;-)

Oh don’t get me wrong, I’ve opened her up real good and have definitely experienced all she has to offer but since she’s my daily rider I’m more conservative in the day to day. I’ve already put over 5k miles on her since I bought her a month and a half ago. Thanks for your reply, I’m hoping the problem is not that involved as I don’t have a garage and working space but good to know what to check next if all else fails. 👊

Reactions: 1

dmfdmf

· #12 · 8 mo ago

Eric1980 said:
I don't see how any of the potential suggestions above explain why the noise only occurs when the bike is in gear. E.g. If the crash bars resonate when the engine is at 5200 RPM, it should also resonate with the bike stopped and in neutral.

The Gladius motor for the Gen2 Wee (2012-2016) had the transmission redesigned to reduce power loss, noise and other "improvements". I think the 2017 Wee uses the same motor/transmission.

From the tech sheet for the Gen2;

Power train that delivers riding comfort (Redesigned transmission and transmission gear with revised final reduction ratio)

I think the redesign created this 5200 RPM vibration so it is coming from the transmission while in gear. The vibration did not exist on the Gen1 bikes. My K7 Wee was smooth as silk all the way to redline.

Reactions: 2

Philbytx

· #13 · 8 mo ago

Mine is like a sewing machine at 6k.

Reactions: 1

Motorpsychology

· #14 · 8 mo ago

Eric1980 said:
I don't see how any of the potential suggestions above explain why the noise only occurs when the bike is in gear. E.g. If the crash bars resonate when the engine is at 5200 RPM, it should also resonate with the bike stopped and in neutral.

The motor needs to be under load at the rpm to create enough amplitude to create the buzz.

Reactions: 3

Silver Badger

· #15 · 8 mo ago

Givi Bars. 😠

Reactions: 1

shinobigami

Discussion Starter · #16 · 8 mo ago (Edited)

Thank you guys for all the input. 🙏
With your help I found the cause/solution for my inquiry. Givi crash bars 🤦‍♂️

I ended up swapping the o rings for electrical tape and replacing the washer with a lock washer, no more sound/vibration! Appreciate this forum and you all.👊

Jaw Gesture Sleeve Elbow Font

Product Font Parallel Screenshot Slope

See less See more

2

Reactions: 3

Brockie

· #17 · 8 mo ago

I also had these vibrations when I first fitted Givi crash bars. I replaced the block connecting the two halves of the crash bars with a garden hose fitting. Perfect fit.

Camera accessory Camera lens Lens Cameras & optics Optical instrument

See less See more

Reactions: 3

14ozarkstrom

· #18 · 8 mo ago

Good to know was thinking of givi bars for mine. Thank You.

Reactions: 1

Kramer

· #19 · 7 mo ago

Try cleaning and re-lubing the chain. I had a vibe at approx 5k - went away after cleaning and lubing.

shinobigami

Discussion Starter · #20 · 7 mo ago

Kramer said:
Try cleaning and re-lubing the chain. I had a vibe at approx 5k - went away after cleaning and lubing.

I’ve already solved my problem, thanks for the insight though. I’ve cleaned and lubed my chain about 5+ times last month due to putting over 5k miles down, it’s such a pain. I’ve actually been debating on installing a Scottoiler auto lube system. 🤷‍♂️

Reactions: 1

1 - 20 of 24 Posts

This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.