S10 Owners, Feeling the Vibes?

[Twitch]

I have a kaoka cruise and that does help some, but not enough.
Thanks for offering some ideas, but I have decided to sell the bike. I am selling parts in the for sale section.

Sorry to hear this, Jim. Bummer, but I understand and would be doing the same thing under those circumstances.

 

[jajpko]

Thanks, at this time I don't have a bike picked out and may not. I have been writing checks for years and my body has been able to cash them, but now, it is getting real slow about it.. I am going to wait until spring and in the meantime work out like hell. I should know by then..

 

[Mellow]

Well Jim, hope it does work out for ya. The Milan bike show is coming up in 2-3 weeks so if Honda is going to release their ADV bike, it may be then and if it's a V4 it will be the smoothest ADV bike on the market - just my biased opinion of course.

 

[jajpko]

Well Jim, hope it does work out for ya. The Milan bike show is coming up in 2-3 weeks so if Honda is going to release their ADV bike, it may be then and if it's a V4 it will be the smoothest ADV bike on the market - just my biased opinion of course.

Thanks Mellow, I am sure whatever I do will work out. I know what you mean about biased. ::025::

 

[terryth]

A good explanation of the vibration modes of twin cylinder engines
http://www.advrider.com/forums/showthread.php?t=545850&page=655

 

[RMac]

Very cool explanation. Shame about the pie throwing contest embedded in it though. So, I wonder why I found the R1200GS to have heavier vibration than the S10 both times I test rode it?

 

[GrahamD]

Very cool explanation. Shame about the pie throwing contest embedded in it though. So, I wonder why I found the R1200GS to have heavier vibration than the S10 both times I test rode it?

Because the theory is taking about mass reciprocation. There are more things going on than just that. When you start a BMW you will get the "lurch to the right" so you have other things like torque effects coming into it. As well as that some bikes are built thin and have different frame resonances and the motor is pulsing side to side as well.

You have recoil action when the cylinder fires, just like a gun. The pressure is pushing the piston down and the head up hopefully along with the motor. The piston usually looses and goes down. The block flexes as well becaue the crank and head are tied together by the block and it has to cope with that force , some flex more than others. Lot's of little things going on that tend to bust the apparently perfect balance of the boxer.

If you rev a Boxer it wants to twist along the length of the bike, Each bang is a "twist pulse" so the bike reacts by twsting left bar up, right bar down or Vice versa depending on the which way the motor is rotating. The resonance will be the same but out of phase.
The twin will want to twist the bikes front up or down. YAMAHA tried to make that twist force centre of the bike. Both ends of the bars will rise in unison and the resonance will be up down but the same (in phase).

Then their are bell mode standing waves that will change according to frequency (revs) and the bars and frame have their own little party going on there.

BMW already have the twist force centre, but it can change cornering attitude slightly if you accelerate hard.

And then there is combustion instability, especially in lean engines, It's hard to make every bang the same, so you get torque reactions induced that way as well.

So, as I used to say to people on the phone, If you like it better, It's better. It was a lot simpler than trying to explain it.
It was a different engineering field but the crap was the same.

Cheers
Graham

 

[Mellow]

Sounds about like mine. Keep us posted of your results after going back to factory settings.

Rod

Rod, I reset the Gas O2 setting from 6 to 0. I have a 400 mile round trip to OK this Saturday to see what difference I do or do not feel. I'll reset the air screw after that as I have a 300 mile round trip to cen tx on Sunday... I should be able to get a good feeling on if those really make much difference.

 

[colorider]

Rod, I reset the Gas O2 setting from 6 to 0. I have a 400 mile round trip to OK this Saturday to see what difference I do or do not feel. I'll reset the air screw after that as I have a 300 mile round trip to cen tx on Sunday... I should be able to get a good feeling on if those really make much difference.

I'm still at the 270CCW and +3, but real tempted to try 180 (or maybe stock) and "0". Problem is I'm running out of season here and it's hard to really give the bike a good test at various settings.

 

[Mellow]

I'm still at the 270CCW and +3, but real tempted to try 180 (or maybe stock) and "0". Problem is I'm running out of season here and it's hard to really give the bike a good test at various settings.

I did tap the wire for the settings and coiled a wire under the rider seat so I could ground it and change the setting without having to mess with the rear seat hump. Too bad the air screw isn't as easy to get to but it's not too bad.

With you being at a higher altitude your settings are probably not going to work for me and visa versa but good to see how the differences work for each of us.

 

[colorider]

I did tap the wire for the settings and coiled a wire under the rider seat so I could ground it and change the setting without having to mess with the rear seat hump. Too bad the air screw isn't as easy to get to but it's not too bad.

With you being at a higher altitude your settings are probably not going to work for me and visa versa but good to see how the differences work for each of us.

I did the same on the wire, and not really sure how the overall elevation thing shakes out. On my trip to TexSTOC, I really did not see much difference other than the normal "it runs better at lower elevations"!!!!

 

[RMac]

Thanks for taking the time to write this!

When I wrote the question about boxer engine it was kind of rhetorical as I realized that the balance diagrams in the ADVRider thread were not including more real-life details such as fact that the engine will include counterbalancers, etc to remove the primary reaction forces. Guess it all boils down to how well it is done for each engine and the wealth of factors you mentioned. Interestingly he refers to the 90 deg twin being in perfect primary balance. Didn't look like that to me. Looked like a constant rotating imbalance that would have to be nulled out somehow in real life(?) Another complicating factor to this discussion is the generation of harmonics I suppose. Guess that mass of engine, the frame, etc will act like a low pass filter. Anyway, enough of my speculation. I am the wrong kind of engineer, the electrical kind

Because the theory is taking about mass reciprocation. There are more things going on than just that. When you start a BMW you will get the "lurch to the right" so you have other things like torque effects coming into it. As well as that some bikes are built thin and have different frame resonances and the motor is pulsing side to side as well.

You have recoil action when the cylinder fires, just like a gun. The pressure is pushing the piston down and the head up hopefully along with the motor. The piston usually looses and goes down. The block flexes as well becaue the crank and head are tied together by the block and it has to cope with that force , some flex more than others. Lot's of little things going on that tend to bust the apparently perfect balance of the boxer.

If you rev a Boxer it wants to twist along the length of the bike, Each bang is a "twist pulse" so the bike reacts by twsting left bar up, right bar down or Vice versa depending on the which way the motor is rotating. The resonance will be the same but out of phase.
The twin will want to twist the bikes front up or down. YAMAHA tried to make that twist force centre of the bike. Both ends of the bars will rise in unison and the resonance will be up down but the same (in phase).

Then their are bell mode standing waves that will change according to frequency (revs) and the bars and frame have their own little party going on there.

BMW already have the twist force centre, but it can change cornering attitude slightly if you accelerate hard.

And then there is combustion instability, especially in lean engines, It's hard to make every bang the same, so you get torque reactions induced that way as well.

So, as I used to say to people on the phone, If you like it better, It's better. It was a lot simpler than trying to explain it.
It was a different engineering field but the crap was the same.

Cheers
Graham

 

[GrahamD]

Anyway, enough of my speculation. I am the wrong kind of engineer, the electrical kind

Did you know that all of this stuff can be converted to electrical equivalents and run through SPICE models.
You could do a SPICE model of each bike and find out exactly what is going on, except maybe the combustion instability , but that could probably done by injecting a random noise on top of a constant impulse signal.

Anyway I am sure YAMAHA engineers probably do that in their sleep. It's not something that is a weekend amateurs job that's for sure. I think engineering CAD packages probably do that anyway these days. They probably just drew up a few S10 variations, got a few made and went and picked the ones that "felt right". ::024::

Cheers
Graham

 

[RMac]

Nah, not quite so into it to try that. Besides only a few guys use Spice these days and I am not one of them. It's all gone over to much fancier, glitzier and expensive simulation tools these days. At-least in my field, that is. Cool to keep it at a hangar talk level though. More fun ::001::

 

[GrahamD]

Yeah, SPICE. just a generic term for black magic Voodoo mecha - electronic software stuff.
Plenty of it around these days, with all the "Super computers" sitting on desktops.

Wouldn't mind getting back into a bit of it, but on the other hand it would cut into my already scarce riding time, so prolly not.

::003::

 

[Scottie Boy]

Tomorrow morning, I have an appt. to meet with Yamaha's regional rep. He is supposed to compare my bike to the demo bike and hopefully give an honest opinion about my vibration problems. Wish me luck!!!!!!

 

[~TABASCO~]

Yea, let us know... Im interested to see what he will say.....

 

[GrahamD]

Tomorrow morning, I have an appt. to meet with Yamaha's regional rep. He is supposed to compare my bike to the demo bike and hopefully give an honest opinion about my vibration problems. Wish me luck!!!!!!

Good luck, looking forward to the outcome.

 

[Scottie Boy]

Last night, I removed my Bark Busters, Grip Puppies, and bar risers that I had previously installed in an effort to try and mitigate some of my vibration issues. I wanted to return the bike back to stock so that Yamaha could not blame any of my accessories. I mentioned before in the other vibration thread and also over at ADVrider that my bike seems to be much smoother in colder temps. So of course, I have a 9 a.m. appointment on the coldest morning in months. On the way to the dealership, I coulnd't believe how smooth the bike was running. Crap, they're going to think I'm crazy.

The Yamaha rep arrived on their demo model and we swapped bikes and went for a ride. When we returned, we both agreed that the bikes ran the same. Fortunately, I had mentioned to the service guy a month ago that my bike did not like hot weather, so they didn't think that I was completely nuts. The Yamaha rep was very understanding and assured me that he believed me. He gave me his card and instructed me to give him a call if the bike starts vibrating again when the weather warms back up. Luckily, Yamaha's southeastern headquarters where he works is only five mile from my house.

So as of now, my bike seems to be running flawlessly. I just hope that it stays that way and I can finally start enjoying my new motorcycle.

 

[stevepsd]

Fortunately, I had mentioned to the service guy a month ago that my bike did not like hot weather,

I wonder if your bike is suffering from a ever-so-slightly lean misfire when hot? It could be misfiring just ever so slightly to cause a engine imbalance which would be felt as a vibration. Since the air is less dense whit high ambient conditions, the fuel mixture leans out somewhat....it could also be something in the ignition system that is breaking down and producing less spark energy when in hot ambient conditions....

Have you pulled * checked your plugs and spark plug caps? Since I don't believe our bikes have Iridium plugs I would try a set of those as well. Did you try increasing the CO settings?

Just a thought.

-steve