Vibrates and is a bit sluggish around 2000-2500 rpm

[JohanH]

I recently purchased a 2015 NC750X

After riding the bike a few times, I have noticed that it vibrates and is a bit sluggish around 2000-2500 rpm. If I shift down, there is no problem, it runs fine and gives good and fast acceleration. But when I ride the bike in any gear around 2000-2500 rpm the engine does not respond smoothly and it "begs me" from the engine sound to downshift.

Is this a normal Honda NC750X feature, or is it a problem?

 

[jeremyr62]

Over here that’s called lugging the engine. By the sounds of it you are in the wrong gear. The DCT does it in D mode too so don’t feel bad. Some claim it is OK and normal but my mechanical sympathy won’t let me tolerate it. My VFR1200 DCT is the same although that has a bit more poke to drive out of it.

 

[JohanH]

Over here that’s called lugging the engine. By the sounds of it you are in the wrong gear. The DCT does it in D mode too so don’t feel bad. Some claim it is OK and normal but my mechanical sympathy won’t let me tolerate it. My VFR1200 DCT is the same although that has a bit more poke to drive out of it.

Thanks. "Lugging the engine" was new to me Is there a solution (besides gear down?

 

[CamaroEric]

No. Shift down or use less throttle. In normal riding I have no trouble riding out from about 2200 but I am a fairly tame rider.

 

[Possummanj]

Shift down. I have the DCT and my left thumb is busy

 

[dduelin]

I recently purchased a 2015 NC750X

After riding the bike a few times, I have noticed that it vibrates and is a bit sluggish around 2000-2500 rpm. If I shift down, there is no problem, it runs fine and gives good and fast acceleration. But when I ride the bike in any gear around 2000-2500 rpm the engine does not respond smoothly and it "begs me" from the engine sound to downshift.

Is this a normal Honda NC750X feature, or is it a problem?

s this a normal Honda NC750X feature, or is it a problem? Yes it is and no it is not.

 

[Possummanj]

Normal --ride it in "sport" or just shift it down when needed --it is trying to maximize gas mileage ---I ride in "normal" mode most of the time but I often find clicking down a gear or 2 for a corner or a hill is the way I would ride if it was a manual trans---it is good to go most of the time --I find sport mode a bit busy unless I am in the twisties

 

[670cc]

Normal --ride it in "sport" or just shift it down when needed --it is trying to maximize gas mileage ---I ride in "normal" mode most of the time but I often find clicking down a gear or 2 for a corner or a hill is the way I would ride if it was a manual trans---it is good to go most of the time --I find sport mode a bit busy unless I am in the twisties

“Sport” and “normal” may mean nothing to the OP if they ride a manual transmission NC750X. Their NC750X’s transmission type was never disclosed.

 

[Possummanj]

“Sport” and “normal” may mean nothing to the OP if they ride a manual transmission NC750X. Their NC750X’s transmission type was never disclosed.

I realize that but anyone riding a manual bike wouldn't even ask the question--they would naturally shift down to stop lugging the engine--it almost has to be a DCT newbie--I found the DCT didn't mind remaining in a higher gear than I would on a manual bike --but then I have owned many over the past 50+ years

 

[lootzyan]

If you don't want to believe in mechanical science and physics, that's fine. But today, for many people, the Internet provides a sufficient source of information. And there you can easily find a fairly simple explanation why lugging the engine is bad.
Honda didn't invent mechanical science and certainly can't say that lugging the engine is normal and unproblematic. This is a problem with the multi-gear manual transmission. And the DCT is based on such a transmission. The problem is less noticeable on manual transmission vehicles as the user learns quickly how to avoid it. Honda wanted to correct the problem by introducing more driving mods in later versions of the NC DCT.
This is not about some catastrophic prophecy, but a statement of mechanical and physical fact.

 

[the Ferret]

I dont believe you can technically lug a DCT transmission. It will downshift itself before lugging/damage can occur. Lugging in a manual transmission occurs when the rpms are too low and the throttle is fully opened and the load becomes excessive. A DCT wont allow that to happen.

That doesnt mean though that you wont feel an exaggerated 270 degree throb when going up a hill, or that it wouldnt be diminished by hitting the downshift button and raising the revs, it just means that it won't damage the engine by leaving it in the higher gear until it feels the need to downshift itself.

 

[670cc]

The 670cc/745cc New Concept engine is in it’s 12th year of sales. The engine has been installed in the NCX, NCS, Integra, CTX, NM4, X-ADV, and Forza variants. I don’t know the sales numbers, but let’s just say a lot of them were sold and in use.

I know of no report of a New Concept engine with damage or failure attributed to “lugging”. It is a robust engine. Use the engine as you like and don’t worry about it.

My NC spends 95% of it’s time between 2000 and 3500 RPM. On very rare occasions I operate it down to 1700 RPM. Works fine, lasts a long time.

 

[dduelin]

If you don't want to believe in mechanical science and physics, that's fine. But today, for many people, the Internet provides a sufficient source of information. And there you can easily find a fairly simple explanation why lugging the engine is bad.
Honda didn't invent mechanical science and certainly can't say that lugging the engine is normal and unproblematic. This is a problem with the multi-gear manual transmission. And the DCT is based on such a transmission. The problem is less noticeable on manual transmission vehicles as the user learns quickly how to avoid it. Honda wanted to correct the problem by introducing more driving mods in later versions of the NC DCT.
This is not about some catastrophic prophecy, but a statement of mechanical and physical fact.

View attachment 51843

I’m of a belief that Honda engineers know how to prevent the engine from damaging detonation. No matter what auto drive mode is selected the DCT’s PCM is programmed to downshift to a lower gear before lugging occurs and it prevents riders from up shifting too soon even in manual mode.

 

[670cc]

If you don't want to believe in mechanical science and physics, that's fine. But today, for many people, the Internet provides a sufficient source of information. And there you can easily find a fairly simple explanation why lugging the engine is bad.
Honda didn't invent mechanical science and certainly can't say that lugging the engine is normal and unproblematic. This is a problem with the multi-gear manual transmission. And the DCT is based on such a transmission. The problem is less noticeable on manual transmission vehicles as the user learns quickly how to avoid it. Honda wanted to correct the problem by introducing more driving mods in later versions of the NC DCT.
This is not about some catastrophic prophecy, but a statement of mechanical and physical fact.

If, as you say, “Honda wanted to correct the problem by introducing more driving mods (sic) in later versions of the NC DCT”, then to what degree did Honda change D mode behavior, the mode that favors the lowest RPM, in later DCT versions? Was the change successful?

 

[lootzyan]

...Was the change successful?

I am not arguing that the change was successful. I haven't had a chance to try the new NC DCT version. And that's not the point. The question was whether lugging of the engine could be considered harmless behavior and is without problems. I don't think that's debatable.

 

[lootzyan]

I’m of a belief that Honda engineers know how to prevent the engine from damaging detonation.

At least on my 2015 CTX700ND this is not true. Lugging is easily noticeable and is not corrected until the engine has developed enough power to overcome the opposing forces.

 

[670cc]

I am not arguing that the change was successful. I haven't had a chance to try the new NC DCT version. And that's not the point. The question was whether lugging of the engine could be considered harmless behavior and is without problems. I don't think that's debatable.

Do you have an example of a particular NC engine that was harmed or has problems attributed to so-called lugging? I can’t say there is or isn’t, onIy that I don’t know of any. If there are no real world examples, then maybe it’s not a potential problem we should be concerned about.

 

[670cc]

I’m of a belief that Honda engineers know how to prevent the engine from damaging detonation.

At least on my 2015 CTX700ND this is not true. Lugging is easily noticeable and is not corrected until the engine has developed enough power to overcome the opposing forces.

lootzyan, it appears that you are substituting the term “lugging“, for dduelin’s term ”damaging detonation”. Lugging is a subjective term, or a perceived engine operating condition, while damaging detonation is objective and could be determined by engine inspection or autopsy.

 

[dduelin]

I am not arguing that the change was successful. I haven't had a chance to try the new NC DCT version. And that's not the point. The question was whether lugging of the engine could be considered harmless behavior and is without problems. I don't think that's debatable.

You implied that the NC DCT allows damaging lugging but the rpm range the OP mentioned is within the table below published in the owners manual. Honda would not recommend operation in a gear, speed and resultant rpm that would result in damage. If Honda recommends it with the manual transmission model it follows that the shift points are programmed at similar or the same speeds. It's not hard to see that what you think is lugging and what Honda thinks is lugging this engine is not the same. Your reference is ignorant of the fact that Honda designed this engine for low and mid range efficiency. The internet reference is speaking in generalities. What gasoline motorcycle engine is producing 81% of peak torque at 2000 rpm and 92% at just 2500 rpm?

I bet looking at this gives you the willies but Honda sleeps just fine at night:

 

[lootzyan]

Show me where I mentioned "damaging detonation" or "RPM" or "the engine was damaged". Where does it say I implied something if it is easily noticeable (if you are able to recognize and name the symptoms correctly). And I have spent many years diagnosing and servicing internal combustion engines.
Below is exactly what I wrote so far.
Lugging is not a good technical term. But it is professional slang commonly used.
I am not the first to notice that this problem also occurs in NC motorcycles. Just look at posts #2, #4, #5.
There will be no discussion with someone who is in complete denial. Whatever you call it, lugging is a complex mechanical process that needs to be understood and denial is due to ignorance.
I certainly "don't get the willies" reading technical and scientific articles. It's my profession. I'm a f*****g engineer. And who are you...?

"If you don't want to believe in mechanical science and physics, that's fine. But today, for many people, the Internet provides a sufficient source of information. And there you can easily find a fairly simple explanation why lugging the engine is bad.
Honda didn't invent mechanical science and certainly can't say that lugging the engine is normal and unproblematic. This is a problem with the multi-gear manual transmission. And the DCT is based on such a transmission. The problem is less noticeable on manual transmission vehicles as the user learns quickly how to avoid it. Honda wanted to correct the problem by introducing more driving modes in later versions of the NC DCT.
This is not about some catastrophic prophecy, but a statement of mechanical and physical fact."
"I am not arguing that the change was successful. I haven't had a chance to try the new NC DCT version. And that's not the point. The question was whether lugging of the engine could be considered harmless behavior and is without problems. I don't think that's debatable."
"At least on my 2015 CTX700ND this is not true. Lugging is easily noticeable and is not corrected until the engine has developed enough power to overcome the opposing forces."