Engine Vibration

[736cc_imp]

My 2013 CB1100's most noticeable engine vibration is during very low rpm roll-ons, specifically idle to 2100 rpm. I never really noticed it until lately, in my old age I am happily content to short-shift thru the gears. Is this vibration normal w/ the CB1100? No engine mods other than 1 tooth larger countershaft sprocket.

 

[rboe]

I have not noticed one on my CB, so I'll have to watch for it tomorrow.

 

[Guth_imp]

I've not noticed any vibrations in the RPM range you've mentioned, but that's certainly not to say that they don't exist. The range of vibrations that stand out to any one individual might be entirely different than those that stand out to the next person.

 

[kmoney_imp]

I've noticed some harmonics probably around that RPM. Nothing out of the ordinary though. Inline 4's are inherently unbalanced (though are helped by our balance shafts), so there will always be some vibration there.

Are you lugging it at those RPMs? I don't think I've ever rolled on from idle to 2100 without having the clutch partially disengaged.

 

[rboe]

I checked this on my bike this morning on several slow roll on starts. Very very smooth.

So I'm wondering if one of your injectors is off (e.g. dirty) causing an unbalanced burn leading to the felt vibration. Just brain storming up any idea that may lead to the problem you described.

Otherwise, I'm clueless to what may be the cause.

 

[736cc_imp]

I checked this on my bike this morning on several slow roll on starts. Very very smooth.

So I'm wondering if one of your injectors is off (e.g. dirty) causing an unbalanced burn leading to the felt vibration. Just brain storming up any idea that may lead to the problem you described.

Otherwise, I'm clueless to what may be the cause.

Thanks everybody for checking your bikes to compare. Next time I meet another CB1100 on the road I hope to swap rides to get 1st hand comparison. As to a remedy, :huh:

 

[Ulvetanna_imp]

What is it with CB1100s and roll-ons to 2100 RPM? Who even does that? As anyone knows who is familiar with the design philosophy of the CB, it was designed with extra vibration built into it. The timing is slightly uneven. So it's normal. Clogged injector? When does that even happen? The design statement referred to here so often explains all that.

Right here on this forum.

CB1100 assymetrical cam timing, lift, and duration.

Try riding the bike above 2000 RPM where it should be or get a CB500 lol

I've noticed some harmonics probably around that RPM. Nothing out of the ordinary though. Inline 4's are inherently unbalanced (though are helped by our balance shafts), so there will always be some vibration there.

Are you lugging it at those RPMs? I don't think I've ever rolled on from idle to 2100 without having the clutch partially disengaged.

Careful you are treading on dangerous ground

 

[736cc_imp]

Rode it today ( it rained 12 outa 14 days lately) and decided to keep the revs up. Smooth as a gravy sandwich....
One reason I've been short shifting is because I own a new Ford Ficus w/ a 5 speed stick; you can roll it on from idle and it's super silky smooth no matter what rpm. That's the beauty of fuel injection. Now, wouldn't you think HONDA, the ultimate high tech motor builder in the world would enable our slick CB1100 to handle any load/throttle/rpm to be purfectly smooth?
I also was subliminally influenced by a bro of mine who bought a BMW GT1600 six cylinder. He said he can drop it in 6th gear and ride it from any speed and rpm absolutely perfectly smooth.

 

[Ulvetanna_imp]

Rode it today ( it rained 12 outa 14 days lately) and decided to keep the revs up. Smooth as a gravy sandwich....
One reason I've been short shifting is because I own a new Ford Ficus w/ a 5 speed stick; you can roll it on from idle and it's super silky smooth no matter what rpm. That's the beauty of fuel injection. Now, wouldn't you think HONDA, the ultimate high tech motor builder in the world would enable our slick CB1100 to handle any load/throttle/rpm to be purfectly smooth?
I also was subliminally influenced by a bro of mine who bought a BMW GT1600 six cylinder. He said he can drop it in 6th gear and ride it from any speed and rpm absolutely perfectly smooth.

Yeah well that BMW is a whole different animal! So good on ya mate. Watch it on those gravy samwiches.

 

[rboe]

Hmm, I wonder if you are feeling the engine lugging.

 

[736cc_imp]

Hmm, I wonder if you are feeling the engine lugging.

Apparently I assumed it's not possible to lug w/ fuel injection above idle. But maybe the machine disagrees with my pushing its limits at those rpm's and throttle loadng.
I read that the greatest possible mpg for a gas engine is achieved at the lowest rpm at full throttle. But the amount of load is a variable that changes the equation.
"Hey Doctor, it hurts when I do this; what does that mean? Doctor replies "It means don't do that."
So the answer to all this is the CB1100 shouldn't be rolled on at very low rpm's because it doesn't like that and signals that by a noticeable vibration.

 

[uscgmac_imp]

Try just the oposite and shift gears around 5000 to 5500 rpms or more and see how much fun you can have. This bike likes to be woken up also. It can be a real fun spirited ride in the upper rmps, and smooth too. I know its a fun relaxed bike to ride but nothing wrong riding it like a sport bike too sometimes
Ill meet up with you some day and compare notes. Im the one who saw your bike out in the Hamptons last week. Im also on the Island. You wouldnt of noticed me last week being i was one of those non waiving, loud pirate looking bad biker guys riding the oil leaking shake box. Lol.

 

[beardyweirdy@me.com_imp]

Sorry to get off topic, but.... 'What is that faring 736cc? And how does it feel?

 

[CIP57_imp]

I assume your talking about first gear roll-ons and not upper gears. Roll-ons from that low in the range should be gradual otherwise you will get bog and vibration unless you slip the clutch. Fuel injection (lower gear restrictions)is not set-up for full throttle response @ such a low RPM unless there removed. You can snap the throttle above 3500rpms with no lag or vibration. Just the design of modern EFI bikes.

Edit: You mentioned fuel economy, if your talking about top gear roll-ons 1 tooth up is about 3700prm's @ 70mph in 5th gear. Most manufactures measure 60-80 roll-ons for large displacement which is about 3200-4600 rpms on this bike. 2100 RPMS would putt you around 40-45 MPH in top gear. You would have to feather the throttle not to get vibration in a inline four.

 

[Ulvetanna_imp]

Hmm, I wonder if you are feeling the engine lugging.

Apparently I assumed it's not possible to lug w/ fuel injection above idle. But maybe the machine disagrees with my pushing its limits at those rpm's and throttle loadng.
I read that the greatest possible mpg for a gas engine is achieved at the lowest rpm at full throttle. But the amount of load is a variable that changes the equation.
"Hey Doctor, it hurts when I do this; what does that mean? Doctor replies "It means don't do that."
So the answer to all this is the CB1100 shouldn't be rolled on at very low rpm's because it doesn't like that and signals that by a noticeable vibration.

I read that the greatest possible mpg for a gas engine is achieved at the lowest rpm at full throttle. But the amount of load is a variable that changes the equation. That is true in theory but mostly applies to piston aircraft. Those engines run at a constant throttle setting and RPM for long periods of time and are made to do so. All kinds of detailed charts are provided to tell the pilot where to set the throttle(s), props, mixtures, per altitude and speed and so on.

You could gear a bike super-tall and it would trudge along OK on perfectly flat ground but bikes are geared to have some surplus power to handle the rise and fall of the terrain, and allow for some degree of acceleration for safety's sake.

You have more control at higher RPM, as I mentioned, when I get into traffic on the freeway I'll drop to fourth or third while maintaining the same speed to assure plenty of maneuvering power, until I get into the clear again.

Your bike engines are designed to run that way, it's for the safety of the rider.

You want great mileage, a Prius will do the job.

 

[736cc_imp]

All great replies. Reason I brought up the subject is because I'm riding quite a bit more conservative and relaxed lately. Maybe I'll go back to being a squid....

 

[emptysea]

There's a balance between "Grandpa" and "Squid", 736cc. We have found that installing RLETs helps one find this balance. Install them and discover the joy that is the CB1100.

 

[the Ferret]

:rofl:

 

[rboe]

I'm typically not that aggressive with my roll ons, but now it sounds like I'm more aggressive than you are at the moment. Lugging is not good, so I'll recommend that you dial in a wee bit more gas.

This motor will pull from idle with no throttle no problem; but down in Phoenix you don't want folks running up your back side (they can be an impatient lot) but it does not take much throttle to move out briskly - yet avoid the squid behavior.

My Griso is my hooligan bike, and even that one rarely gets ridden hard (it too quickly gets me in over my head..... ), while the CB does offer some excitement in the upper rpm's, it is not as satisfying as letting the big steam engine of the Griso loose. It's a Guzzi thing.

 

[736cc_imp]

What's RLETs?