Vibrations

[lennya12threh]

I understand that it is normal for single cylinder bikes to start to vibrate and rattle more upon high rpms as they put on some years.

What is the common cause of this?

I can't imagine what it could be, if the performance isn't being damaged and the engine is still running.

The internal parts can't afford to be loose, so it must be something on the frame?

Loose screws or something? I can't imagine.

[thaicbr]

They are getting old, simple as that. like you and me when we are young we are strong and handsome BUT when we get older we are not so strong but still handsome (at least thats what my girlfriend says ABOUT ME )

Edited April 24, 2009 by thaicbr

[PeaceBlondie]

My first CBR150 buzzed about the same at one month as at 58 months and 54K km. New one shakes and buzzes. I got used to it

[lennya12threh]

Well a motorcycle must be slightly different in comparison to an aging human.

I'm sure there is something that could be done about it.

Re-build the entire bike? That should do it.

But obviously every part doesn't need to be re-built to only fix the vibration problem.

Which part?

[dynabob]

what make of bike is it,push rod or timing chain.

if engine is rubber mounted check the mounting's for wear

[Richard-BKK]

In normal situations the vibration of a single-cylinder engine is generated by a not perfect balance of the Rotating Weight and the Reciprocating Weigh of the engine. I cannot see, how this over time can change...

I believe more that your statement is "older engines produce more vibrations then modern engines", this is true. While say 10 years back we had to relay on static balancing technology currently we have computers which give us the capability to reduce vibration to almost zero (which nobody wants also, because vibration is good to keep in touch with the engine) by using dynamic balanced of the fly-wheel and the whole assembly.

Some interesting articles about this subject can be found here Dynamic Balancing and Beginning Blueprinting and A Well-Balanced Flywheel

Edited April 24, 2009 by Richard-BKK

[lennya12threh]

In normal situations the vibration of a single-cylinder engine is generated by a not perfect balance of the Rotating Weight and the Reciprocating Weigh of the engine. I cannot see, how this over time can change...

I believe more that your statement is "older engines produce more vibrations then modern engines", this is true. While say 10 years back we had to relay on static balancing technology currently we have computers which give us the capability to reduce vibration to almost zero (which nobody wants also, because vibration is good to keep in touch with the engine) by using dynamic balanced of the fly-wheel and the whole assembly.

Some interesting articles about this subject can be found here Dynamic Balancing and Beginning Blueprinting and A Well-Balanced Flywheel

I read a bunch on the CBR thread about vibrations that commonly induced over time. Not just an unchanging phenomenon of an old engine.

[Richard-BKK]

Again this is a myth, the engine is not producing more vibration. I researched the phenomena of increasing vibration in several well sponsored projects. In all situations we could not find any increase of engine vibration.

What we as research team found, and we where working at the time for the an Italian motorcycle manufacturer was that, over years people remove and reattach the fairing of motorcycles more then you think. This large hard plastic, carbon or what ever it is made of is like the box of the piano. When it is not correctly connected of some screws are lost or improper connected they can act as amplifiers to the vibrations of a motorcycle engine.

Vibration could also happen due to secondary effects, like missing service checks. For example, the Honda CBR-150R, similar to his worldwide brother vibrates at a frequency that over time can unbalance the ignition coil, changing the firing sequence of the ignition with just a micron of a second already changes the feel of the engine.

This of-set firing sequence will feel like a unbalanced engine. I'm not particularly skilled in Honda engines, but I know that the average Kawasaki engine has service people checking the ignition firing sequence.

Again, people who follow regular service of there motorcycle will not feel any problems...

Edited April 24, 2009 by Richard-BKK

[basjke]

In my opinion is,as dynabob already mentioned,the mounting rubbers from the engine.Rubber gets hard over the time and will transfer the vibrations to the frame more easy.

[Richard-BKK]

Hi Basjke,

You have a good point, but, rubber what has a high flex wears out over the years, and not turns hard. I belief it becomes more like what you see when you hang elastic-rubber in the sun for a day or two... it become bros and falls apart. The vibration of a motorcycle without engine stabilization rubbers would be funny to call increasing over the years. As this is a mostly happens in a period of 1 to 3 weeks.... not months or years.

Even I'm not sure that the Honda CBR-150R is build with stabilization rubbers, it is, for its ages a very stable engine.

Edited April 24, 2009 by Richard-BKK

[lennya12threh]

Again this is a myth, the engine is not producing more vibration. I researched the phenomena of increasing vibration in several well sponsored projects. In all situations we could not find any increase of engine vibration.

What we as research team found, and we where working at the time for the an Italian motorcycle manufacturer was that, over years people remove and reattach the fairing of motorcycles more then you think. This large hard plastic, carbon or what ever it is made of is like the box of the piano. When it is not correctly connected of some screws are lost or improper connected they can act as amplifiers to the vibrations of a motorcycle engine.

Vibration could also happen due to secondary effects, like missing service checks. For example, the Honda CBR-150R, similar to his worldwide brother vibrates at a frequency that over time can unbalance the ignition coil, changing the firing sequence of the ignition with just a micron of a second already changes the feel of the engine.

This of-set firing sequence will feel like a unbalanced engine. I'm not particularly skilled in Honda engines, but I know that the average Kawasaki engine has service people checking the ignition firing sequence.

Again, people who follow regular service of there motorcycle will not feel any problems...

So from I've read, it is very normal for a CBR 150 to vibrate alot and "buzz."

Peace Blondie said the new CBR vibrates and buzzes alot and it has since 1 month old.

It seems my CBR buzzes and it seems uncomfortable. I don't recall it being this way for the first week.

I haven't messed with the body, or fairing at all.

If this is normal I guess it is ok, but if not, I'd like to do something with it, but am no mechanic, so don't know where to start.

-Lenny

[Richard-BKK]

He Lenny,

Yes, some Honda CBR-150R buzz more then others, this has something to do with the production process. But the original question was "start to vibrate and rattle more upon high rpms as they put on some years", and that is not true. A good constructed engine, which sees its regular service appointment will not change its vibration as they put on some years.

If you think that your CBR-150R is vibrating more then you bought it a few months back, you may want a qualified dealer to check if the ignition is still correct. Normally the ignition timing is checked at the first service appointment, it is possible that they skipped this or simply did not see a problem. Do you also have other problems? Like starting problems, less power in high rpms, or other problems if you open or close the throttle quickly?

[PeaceBlondie]

The only special noise that happened long term was a rattle in the head after about 45,000 km. Cam chain, quickly replaced. The standard noises are cowling and fairing shakes. A small bike that cruises easily at 9,000 rpm buzzes.

[Gary A]

As a bike gets older, you become more aware of vibrations and sounds. It's a quirk of the mind to worry about older machines when it is almost exactly what it was when new.

[BSJ]

I'll take vibrations any day over those annoying high frequency tingles you get up thru the hand grips.

And according to vintage and veteran guys vibrations add character!

[Kimera]

I'll take vibrations any day over those annoying high frequency tingles you get up thru the hand grips.

And according to vintage and veteran guys vibrations add character!

Had a Harley once that vibrated. found I could ride it for long periods, sort of unnummed the bum,

[lennya12threh]

Again this is a myth, the engine is not producing more vibration. I researched the phenomena of increasing vibration in several well sponsored projects. In all situations we could not find any increase of engine vibration.

What we as research team found, and we where working at the time for the an Italian motorcycle manufacturer was that, over years people remove and reattach the fairing of motorcycles more then you think. This large hard plastic, carbon or what ever it is made of is like the box of the piano. When it is not correctly connected of some screws are lost or improper connected they can act as amplifiers to the vibrations of a motorcycle engine.

Vibration could also happen due to secondary effects, like missing service checks. For example, the Honda CBR-150R, similar to his worldwide brother vibrates at a frequency that over time can unbalance the ignition coil, changing the firing sequence of the ignition with just a micron of a second already changes the feel of the engine.

This of-set firing sequence will feel like a unbalanced engine. I'm not particularly skilled in Honda engines, but I know that the average Kawasaki engine has service people checking the ignition firing sequence.

Again, people who follow regular service of there motorcycle will not feel any problems...

So from I've read, it is very normal for a CBR 150 to vibrate alot and "buzz."

Peace Blondie said the new CBR vibrates and buzzes alot and it has since 1 month old.

It seems my CBR buzzes and it seems uncomfortable. I don't recall it being this way for the first week.

I haven't messed with the body, or fairing at all.

If this is normal I guess it is ok, but if not, I'd like to do something with it, but am no mechanic, so don't know where to start.

-Lenny

Thank you and everyone else for the input.

Nope, no other problems. Maybe I'm just paranoid.

Starts fine, drives fine, switches gears fine, engine breaking fine, engine sounds good.

Sometimes I just hesitate to give it at higher rpms because it seems like it is harmful to the bike because of vibrations,

and the noise/vibrating makes it undesirable. I'd rather cruise along smoothly.

[tubber]

I have an XJR1200 which more or less has a 25 year old bored out FJ1100 engine, no counter balance shafts or modern technology. Smooth as silk, no vibration. I also have a 2008 FZ-1 which is a buzzy, vibrating, piece of sh!t. Great forward leaps of technology????

[PeaceBlondie]

Some cylinder layouts such as a straight six are naturally balanced, but most are not. My 1981 Suzuki GN400 was a big single with counter-throws on the crankshaft, but no counter-shafts

[lennya12threh]

I also have a 2008 FZ-1 which is a buzzy, vibrating, piece of sh!t.

Well, I sold the CBR and just today got an NC-30. (VFR 400) Seems great!

Though it doesn't seem to take little bumps (Bangkok roads) as good / smoothly as the CBR 150.

[dave_boo]

It's probably a combination of things. An older bike eventually works bits and pieces loose. Doesn't have to be much; but enough could cause mechanical resonance in parts that were previously not affected due to the compression or torsional loads placed on them. A cascade effect could result through various bits to the point where it's extremely noticable.

The loosening of tolerances is exagerated at 9 000 RPM. A bit of flutter in the valve train due to worn cam bearings could amplify back from the furtherest point on the engine. Bad cam timing could be causing detonation at an un-optimal time. Worn cam gears or chains could be slapping around. Weak valve springs could be allowing blowby and detonation inside the exhaust track or the valves to not seat until the firing of the plug forces them shut. Worn piston rings could allow a bit of slap. Wrist pins, subject to tremendous force at both the top dead centre and bottom dead centre from de-acceleration and acceleration forces in addition to the centrifugal force imposed by the rod could be worn or wear out the piston proper. Same could be said at the other end of the rod. Rods themselves, having been through enough heat cycles could exceed specifications due to loss of intial metallugrical properties. Main bearings could be worn allowing the whole assembly to float around. There is also longitudal stress put on the crankshaft, if it's excessive it is much more noticable than the normal vibrations that a single cylinder puts out. There could be significant play in the primary reduction gears that allows vibration. Transmission gears wear out and could be a source. Bad engine, transmission, or even exhaust mounts could induce rattling. Even something as innocous as old bearings or improperly tightened wheel nuts could exhibit vibrations (although you'd have to either be a complete n00b or an idiot not to recognise the difference between that vibration and an engine induced one).

Best thing to do is if it bothers you is to go out and spend that ridiculous (some 300 THB! for a small container) amount of dinero on Lock-tite. Apply to all fasteners. Allow to cure and then take the bike for a ride. Problem solved? Time for a check of the engine. Check your timing and general health. Take it for a test ride. Problem solved? Maybe it's time for a rebuild. When broken down inspect the health of the transmission....

Edited April 26, 2009 by dave_boo

[lennya12threh]

It's probably a combination of things. An older bike eventually works bits and pieces loose. Doesn't have to be much; but enough could cause mechanical resonance in parts that were previously not affected due to the compression or torsional loads placed on them. A cascade effect could result through various bits to the point where it's extremely noticable.

The loosening of tolerances is exagerated at 9 000 RPM. A bit of flutter in the valve train due to worn cam bearings could amplify back from the furtherest point on the engine. Bad cam timing could be causing detonation at an un-optimal time. Worn cam gears or chains could be slapping around. Weak valve springs could be allowing blowby and detonation inside the exhaust track or the valves to not seat until the firing of the plug forces them shut. Worn piston rings could allow a bit of slap. Wrist pins, subject to tremendous force at both the top dead centre and bottom dead centre from de-acceleration and acceleration forces in addition to the centrifugal force imposed by the rod could be worn or wear out the piston proper. Same could be said at the other end of the rod. Rods themselves, having been through enough heat cycles could exceed specifications due to loss of intial metallugrical properties. Main bearings could be worn allowing the whole assembly to float around. There is also longitudal stress put on the crankshaft, if it's excessive it is much more noticable than the normal vibrations that a single cylinder puts out. There could be significant play in the primary reduction gears that allows vibration. Transmission gears wear out and could be a source. Bad engine, transmission, or even exhaust mounts could induce rattling. Even something as innocous as old bearings or improperly tightened wheel nuts could exhibit vibrations (although you'd have to either be a complete n00b or an idiot not to recognise the difference between that vibration and an engine induced one).

Best thing to do is if it bothers you is to go out and spend that ridiculous (some 300 THB! for a small container) amount of dinero on Lock-tite. Apply to all fasteners. Allow to cure and then take the bike for a ride. Problem solved? Time for a check of the engine. Check your timing and general health. Take it for a test ride. Problem solved? Maybe it's time for a rebuild. When broken down inspect the health of the transmission....

Well if only I could do all that. I am a downright newb.

But i'm interested in investing in some tools so I can take her apart if need be and get familiar with the bike and layout.

I've looking for a manual right now but can't seem to find one to download.

[dave_boo]

Well if only I could do all that. I am a downright newb.

But i'm interested in investing in some tools so I can take her apart if need be and get familiar with the bike and layout.

I've looking for a manual right now but can't seem to find one to download.

Nothing wrong with being a newb; there's lots of stuff that I don't know how to do but a healthly attitude like yours will get you along the path to finding out what you're seeking.

It's hard to find a quality set of tools in Thailand. I'm actually afraid to know what an honest-to-buddha set of Snap-on sockets would cost (or even a Mac).

I've tried to attach a scanned copy of the owner's manual in English; send me a PM with your email address and I'll forward you a copy. Sorry it's not that good, but it's better than nothing. I'm still on the look-out for an English service manual.

[mbox]

Well if only I could do all that. I am a downright newb.

But i'm interested in investing in some tools so I can take her apart if need be and get familiar with the bike and layout.

I've looking for a manual right now but can't seem to find one to download.

Nothing wrong with being a newb; there's lots of stuff that I don't know how to do but a healthly attitude like yours will get you along the path to finding out what you're seeking.

It's hard to find a quality set of tools in Thailand. I'm actually afraid to know what an honest-to-buddha set of Snap-on sockets would cost (or even a Mac).

I've tried to attach a scanned copy of the owner's manual in English; send me a PM with your email address and I'll forward you a copy. Sorry it's not that good, but it's better than nothing. I'm still on the look-out for an English service manual.

Hi , not sure if this link is posted somewhere on this forum but here are a lot of free manuals....also saw the vfr400 listed there: http://www.carlsalter.com/motorcycle-manuals.asp

mbox

[dave_boo]

mbox,

Good link, but as typical of those sites they only go down to the CBR 250....

[dave_boo]

You know what; changing my search parameters to include the CBR 125 yielded this interesting site. Now it doesn't have a CBR 150 manual proper, but it does have a workshop spec sheet, exploded parts information, manual, and a Honda common service manual. Mixing and matching along with common sense should be sufficient.

It seems like an older page, some of the linkies are dead, but if someone could do everyone a favour and start compiling it the benefit to the local community would be enormous.

Edited April 26, 2009 by dave_boo

[lennya12threh]

Yea, I just found that one.

Looks good.

I didn't find anything NC30 specific though.

These files:

1. "Honda VFR400"

2. "Honda VFR400R SS.SP 92"

3. "Honda VFR400R microfiche"

4. "Honda VFR400R service manual"

I downloaded 1. and 4. I hope it is specific enough or similar enough to use with an NC-30.