(Not so) Good Vibrations.. gearing change?

[ninjunk]

Just filled up the 7th or 8th tank of gas on my little Ninjette, running about a 20 mile commute that goes from light traffic residential for 2 miles, to 65mph higway (i do about 70) for 12 miles, then 80 on a superhigway for 3 miles.

I'm noticing that around 8,500 rpm there is a vibration, which works out to 63 mph or so. Probably just some kind of natural engine harmonic, not a huge deal but I'm thinking of making a gearing change and I don't want to put that vibration in the middle of my 65-70 cruising range.


Do those of you who have made the 15/45 switch notice a vibration at cruising 65-70? I'm also thinking maybe putting a little more load on the engine will help take some of that vibration out. It seems to be worse when i'm decelerating or under light throttle.

[ninjunk]

oh yeah, speeds that i'm referencing are 'actual' my speedo doesn't work so i use a GPS smartphone attached to my handlebars. I just noticed that on the gearing calculator at Ninja250.org, there is a pretty big descrepancy if you're talking real or indicated.

[csmith12]

No gearing change will solve all the buzziness from the lil ninja. While 15/4x does seem to help a lot, it's still there somewhat.

Also, check your motor mount bolts too.

[ninjunk]

thanks for the reply, yeah i'm not trying to get rid of the natural 'buzzyness' (trust me, i ride two strokes, i'm used to it) there is a very particular harmonic that shows up in my handlebars right from 8300-8600. Just wondering if anyone else specifically noticed that or if it is something i should investigate.

at 10k rpm, the engine is really quite amazing. That must be the 'tuned' rpm for the balance shaft because everything quiets down and gets butter smooth.

I'll go with the 15th just to save wear and tear, see what it does, even if it nets 10% better fuel economy and saves some wear and tear on the engine it is worth it, not like i need the acceleration.

I just checked bolts last night after i realized my left side passenger peg and muffler bolt fell out on the ride home (lost the peg, bummer) nothing seems to be loose.

I lost one of the grab handle bolts last weekend, i loaned the bike to a friend that was in town. Pretty typical bolt shedding for a new bike until I can figure out all what needs lockwasher/safety wire/ loctite and get that taken care of.

[alex.s]

just go faster

[csmith12]

Originally Posted by alex.s

just go faster

this is solution to all life's problems.

[Motofool]

Originally Posted by ninjunk

........... Do those of you who have made the 15/45 switch notice a vibration at cruising 65-70? I'm also thinking maybe putting a little more load on the engine will help take some of that vibration out. It seems to be worse when i'm decelerating or under light throttle.

No vibration from my 2007.

Check that the three engine/frame anchors are torqued down as specified.

If they are, check the chain for wear above the specified limit and for links that cannot be moved easily respect to the next links.

If all OK, check for sideways play in the swing arm pivot.

[Ghostt]

Are you referring to handlhandlebar Buzz? If so I recommend changing the OEM bar ends, to heavier ones, like mine. I have them installed on both the Ninjette and EX500, that and better grips.

Also try relaxing your grip and the bars.

Extra Heavy Bar Ends

[ninjunk]

Thanks Ghostt, thats a good suggestion. I'll probably go ahead and make something like that once I knock out some of the more 'pressing' ergo issues... namely the seat pressing my nuts into the tank.

The bike does 'sit out' and we've had a lot of rain so i think a new chain, front sprocket are in order. It was an o-ring chain at one point but it sat outside before i got it and some genius removed the chain guard so it takes a beating.

[Ghostt]

Originally Posted by ninjunk

Thanks Ghostt, thats a good suggestion. I'll probably go ahead and make something like that once I knock out some of the more 'pressing' ergo issues... namely the seat pressing my nuts into the tank.

The bike does 'sit out' and we've had a lot of rain so i think a new chain, front sprocket are in order. It was an o-ring chain at one point but it sat outside before i got it and some genius removed the chain guard so it takes a beating.

Schoolie is very reasonably priced, and excellent service, he's well know over at EX-500.com,

I'm currently taking orders for these. Once you confirm your orders, I'll put them in the queue and work on them in the order I receive them. When I've got them made, I'll send a message requesting payment. I'll ship them out when I get the money.

I can make them to whatever length you like. Pricing for standard bar ends to length will be as shown in the following table. For anything other than that (bar end mirror grooves, etc.) we can discuss pricing before I get started.

Material Diameter Length Weight (Including bolt) Price
303 Stainless 1.5" 3" 23 oz $45
303 Stainless 1.5" 2.5" 19 oz $40
303 Stainless 1.5" 2" 15 oz $40
303 Stainless 1.5" 1.5" 11 oz $35
12L14 Mild Steel 1.5" 3" 23 oz $42
12L14 Mild Steel 1.5" 2.5" 19 oz $37
12L14 Mild Steel 1.5" 2" 15 oz $37
12L14 Mild Steel 1.5" 1.5" 11 oz $32

Don't buy the 12L14 unless you plan on painting or coating, they will rust if left bare. This just takes a few bucks off if you don't need stainless's rust resistance.

Shipping will be USPS Priority Flat rate of $5.80 for shipments inside the continental US. Contact me for a quote on international shipping.

I'll do my best to get these done as quickly as I can once you ask for them, but please understand that I'm fitting this in in my spare time. I'm trying to give you guys a good deal, please don't buy from me if that doesn't work for you.

If you looking for a chain guard, check this out,

Inexpensive aluminum chain guard upgrade/modification.

[MountainMedic]

I have an '04 that makes a buzz sound somewhere around 7k-8k RPMS. It seems to be coming from a little deeper down below the handlebars closer to the radiator or something. Totally annoying.

[Ghostt]

Originally Posted by MountainMedic

I have an '04 that makes a buzz sound somewhere around 7k-8k RPMS. It seems to be coming from a little deeper down below the handlebars closer to the radiator or something. Totally annoying.

See @Motofool statement above, if it's not a handle bar buzz.

If it is a bar buzz, see miy statement.

[ninjunk]

Forgot I posted this, and since another post just got made asking about this, I figured I'd check back in.

Went to the 15th sprocket, JT brand, very nice. I also replaced my chain and went with a cheap one. I might eventually get around to making a new chain guard but I got other projects for now.

The 7500-8500 rpm buzzing in the handlebars is there and worse, way worse. It now goes up to about 9000 which is exactly 70 mph. My right wrist really takes a pounding on the ride into work.


That said, spreading out the gears with the taller sprocket makes the bike a lot more rideable in traffic. You don't run out of gear as quickly and you can actually use the lower gears for riding around rather than having to just click through them. The bike probably could take a few more teeth off the rear sprocket and still be rideable but for now stock rear and 15 front are working well.

I used the same length 106 link chain and it is slightly further in on the adjuster but well within range.

I'm getting a really nasty whine in my final drive from something, either my cush drive carrier bearing, wheel bearing, or output shaft bearing are getting ready to go, hopefully its not the output shaft one, i think that dictates a split engine case...

[Motofool]

Bearings that are going bad make a high pitch noise.
Sound from output shaft will change more when torque changes.