Vibration/shudder on higher gears when on the throttle

[marky777]

I found this problem with my newly acquired 2015 750X DCT. When on the throttle in the higher gears there's shudder from the engine area.
Anyone else have this problem? i saw some people say it's the nature of the auto gearbox it changes to 6th too soon before the revs pick up.

 

[dduelin]

This is normal and in no way is harmful to the engine or transmission. If it bothers you you could choose one of the S modes so the transmission shifts at higher rpms.

 

[davidc83]

yea, normal. 6th gear is like an overdrive and it behaves better at a higher rpm/speed. Ride in manual mode and downshift to 5th or as dduelin states, ride in a s mode and it shifts later....

 

[Deckyon]

I stay nearly 100% in S-mode, shifting up or down depending on situation. D-mode will save you gas, in the long run, but for me, S-mode is more comfortable and shifts generally where I would be anyway.

 

[lootzyan]

This is normal and in no way is harmful to the engine or transmission. ...

Lugging the engine - It's not normal and of course it's harmful to the engine.
This problem has been described so many times that there is no reason to discuss it again.

 

[670cc]

Lugging the engine - It's not normal and of course it's harmful to the engine.
This problem has been described so many times that there is no reason to discuss it again.

I hope Honda realizes what they’ve done wrong. The DCT is programmed to shift to sixth early in D mode. It’s a shame Honda is harming the engine by design. Sarcasm, of course, but the point is, as dduelin stated, it is normal behavior per the design of this motorcycle, and is not cause for concern. If you don’t like it, shift to a lower gear.

 

[TheIronWarrior]

Lugging the engine - It's not normal and of course it's harmful to the engine.
This problem has been described so many times that there is no reason to discuss it again.

Lugging the engine and an engine that vibrates at low RPM are two different things though. Have you ever ridden a Harley? Those things shake at any speed due to the design of the engine, mostly the firing order/crank angle. The NC700 engine is intentionally unbalanced to induce some "character" and make it FEEL more like a V twin than the parallel twin it is (270 degree crank angle, simulates a 90 degree V). Depending on the severity of the noted "shudder", all the OP is noticing is engine "character". If this is the case, it is entirely normal and will NOT damage the engine, because it is NOT lugging. If it is more severe than the "normal shudder" it could be indicative of lugging, which may harm the engine. The fact that the "problem" has been discussed "so many times" makes me think it's most likely "normal shudder" and not "lugging" in most (if not all) cases.

 

[lootzyan]

...The NC700 engine is intentionally unbalanced to induce some "character" and make it FEEL more like a V twin than the parallel twin it is (270 degree crank angle, simulates a 90 degree V)...

It sounds ridiculous because... it is ridiculous. It's made up story... but why?
Or... If you have any proof that Honda's design team "intentionally unbalanced (mass-production cheap engine) to induce some "character" and make it FEEL more like a V twin", I'll be glad to read it and apologize to you for calling you... an uninformed.

 

[HarveyM]

Ash on bikes said the same in his 2012 review:
https://www.ashonbikes.com/content/honda-nc700x-0 "Just one balance shaft is used in the NC700X engine, partly to endow it with some character by allowing for a degree of vibration, partly to minimise weight and friction,"


Honda on release of the 700 noted "To concretely arrive at a "ride to suit mature tastes," a choice had to be made between even and uneven firing intervals. Uneven-interval firing with a 270º phase crank was chosen over orderly and smooth even-interval firing in order to achieve a throb close to that of a 2-cylinder V-engine, because this would result in an emotional yet comforting means of daily transportation." Honda Worldwide | Global 700cc Engine for Next-Generation | Introduction

As for the DCT lugging, Honda has been making the engine for six years and has done a redesign (700 to 750). If they were worried about it, they would have 'fixed' it.

 

[TheIronWarrior]

It sounds ridiculous because... it is ridiculous. It's made up story... but why?
Or... If you have any proof that Honda's design team "intentionally unbalanced (mass-production cheap engine) to induce some "character" and make it FEEL more like a V twin", I'll be glad to read it and apologize to you for calling you... an uninformed.

"An extra balancer shaft was added to make the engine feel refined, while retaining the distinct “throb” delivered by its 270-degree firing order. A unique intake-port layout and valve timing that’s different for each cylinder also help to give this unique engine a distinctive character." from the NC750X Brochure. Bear in mind the 700 has only ONE balance shaft, so it's even less "refined" than the 750 motor. The intake port layout and timing is similar on both engines.

"However, in order to achieve the emotional comfort of a slightly rough throb and satisfy the development concept of a "ride to suit mature tastes," the team made a deliberate decision keep the vibration and go with the uniaxial primary balancer instead of its vibration-eliminating biaxial cousin." SOURCE

" The primary vibration of a 270° crank can be balanced perfectly using a biaxial balance shaft, giving the two cylinder engine the smoothness of a Gold Wing's horizontally-opposed six-cylinder engine, but the Integra was deliberately designed with a uniaxial primary balancer, which delivers smoothness together with a satisfying engine feel. This feel is further enhanced by the collective intake port design of the cylinder head. This arrangement means there is some interference between the gasses flowing into the two cylinders. Together with the valve timing, which is set differently for each cylinder, the result is a unique and distinctive feel to the engine." SOURCE (Integra uses the exact same engine as the NC700)

"A 270-degree crank imitates the sound and feel of a 90º V-twin, and there are other advantages. In contrast to the 360 and 180 parallel twins, the 270 crank gives a compromise that allows a more regular firing pattern than a 180-crank, and less vibration than a 360-crank." SOURCE

"A feature of the 270° parallel twin is that it provides most of the feel of the popular V-twin layout, along with further advantages: it is simpler and cheaper both to produce and to maintain; it needs only a single cylinder block and head; induction, exhaust and cooling are simpler; the engine is lighter and has better potential for an optimum CG position; battery location is easier; rear suspension design is simpler; and it allows a shorter wheelbase for sharper handling." SOURCE

But please tell me more about how I am uninformed and how the Honda engineers deliberately designed their transmission to harm the engine they also designed...

 

[Jos]

I guess he means the cranking (firing order) if voluntarily irregular ("big" bang). Of course the engine is balanced, it would not last long if not.

 

[lootzyan]

Now again we are close to argue an honesty of Honda's Public Relations department.
And it's working.
Do you remember PCM "Learning function" story?
They fooled me, that's for sure.

2011 Ash's article was a part of NC PR campaign.

 

[TheIronWarrior]

The fact stands that they could have eliminated basically all engine vibrations (smooth as an inline 4) with a biaxial balance shaft and they chose to go with a single uniaxial shaft and leave in some vibrations. Whether the "character" was meant to be a feature or if that's the positive spin they chose to put on a cost saving decision, the physics still applies and the engine has been intentionally designed to have some vibration. Other manufacturers (as listed above) have also used the 270 degree crank angle for the same stated reasons, and with similar results.

 

[670cc]

With the NC now in its 7th production year, and with some examples now surpassing 100,000 miles use, I’ve not heard any reports of an engine failure resulting from simply allowing the motorcycle to operate within the shift point/RPM parameters programmed into the DCT. Until then, some people are just worrying about nothing.

 

[Doc True]

Now again we are close to argue an honesty of Honda's Public Relations department.
And it's working.
Do you remember PCM "Learning function" story?
They fooled me, that's for sure.

2011 Ash's article was a part of NC PR campaign.

Any evidence against the conspiracy is evidence for the conspiracy.

 

[dduelin]

Lugging the engine - It's not normal and of course it's harmful to the engine.
This problem has been described so many times that there is no reason to discuss it again.

Then why bring it into the discussion again?

The Honda owner's manual lists the same absurdly low shift points for the manual transmission version and Honda isn't in the business of publishing suggestions in the owner's manual that would harm the engine. Sure, they are very low engine speeds but not harmful to this engine. Now if you shift the bike at even lower rpms then those suggested by the Honda engineer-sans then you might be lugging it but the DCT won't let you do that.......that would possibly harm the engine.

 

[Olythom]

Marky. I also have a 2015 DCT. If the vibration / shudder is only in the higher gears and only under fairly heavy acceleration, you are probably just feeling the shuddering (or lugging) that the guys are 'discussing' above. The engine is a torquey design and Honda asks it to shift (DCT version) or recommends that you shift (manual version) at lower-than-usual rpm. This will get you some great gas mileage but it sometimes feels like you're climbing a hill in 5th gear in the family truck. It is normal for this bike. I trust Honda engineers about as much as any that I've ever come across. It's in the bike's blood. If you're uncomfortable with it, hit the downshift button (left thumb) and the the shudder goes away with the downshift.

Riding in "S" mode eliminates the shudder and gives the bike a more spirited feel but it will also cuts down on the incredible gas mileage of this cool little machine as well.. I ride in "D" mode most of the time and use the left thumb downshift very frequently - for slowing/stopping and to grab a little extra acceleration when needed. I have looked at and tested several bikes since I bought the NC and I have not found anything better for economical, fun commuting.
>Thom

This is Skookum. Doesn't everyone name their bike???

 

[marky777]

Thank you everyone! You have been tremendously helpful.

Tried S mode (I only have 1) and the shuddering doesn't occur.

 

[Deleted member 1183]

I stay nearly 100% in S-mode, shifting up or down depending on situation. D-mode will save you gas, in the long run, but for me, S-mode is more comfortable and shifts generally where I would be anyway.

This is also my favoured use of the DCT system. S1 mode + manual mostly on upshifts. For me D mode shifts too early and S1 holds on to the gears too long. For that reason I upshift manually at about 4000rpm unless I am in a real hurry when I let S1 take over completely.

 

[jmark10]

Thank you for this thread! Brand new rider with a 2015 DCT as well, and even though I am brand new, I could tell that the vibration/shudder wasn't "normal". I haven't ridden in Sport mode or played in Manual mode at all yet, and it happens exactly at steady throttle, 40 mph, every time. I'm so glad to see that it actually IS normal. Now to ride in Sport mode!

Edited to add - YUP! Played in Sport Mode last night, and no vibration/shudder whatsoever. It's totally caused by it shifting into 6th super-early and kindof lugging. I could feel it in the bike but the vibration/shudder was at the exact same tempo as the exhaust notes - which was a clue, but now I'm sure. Double thanks for this post.