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Noisy Gearbox

17K views 30 replies 14 participants last post by  mitra  
#1 ·
The gearbox of my Icon is relatively noisy when doing a coastdown.
It's a howling noise and sounds as if the gears were 'straight-cut'. (like an older car in reverse gear)
Is this normal? - Is this even typical? - Or may I have an Issue with my bike(currently 600km).
Did someone make the same experience?
 
#2 ·
I just learned by talking to a colleague that the gears of a sporty motorbike like all other motorsports use straight cut gears.
Then the noise is logical consequence. Well, - then it's like it is.
In some situations I hear more of gearbox then from the engine.
 
#8 ·
It's normal for the Scrambler and maybe other Ducatis but my Hondas never had that sound, at least not anywhere as noticable. I think it sounds terrible. I would love to get rid of it.

Ducati never was known for good gearboxes so maybe this is somehow connected?
 
#9 ·
I rode a Guzzi V11 Sport that had them as well and over time they quieted down a bit with wear. I personally don't mind the sound and find it reassuring that everything is working as designed. I have read that straight cut gears are stronger than helical cut gears in addition to being cheaper to produce.
 
#10 ·
The reason straight cut gears are used in motorsports is the better performance to weight ratio, because they do not have to handle with axial forces at the shafts.
Now again a balance of interests: comfort against weight!
For me the gearbox noise and the tricky throttle handling at low rpm and little open throttle are the only annoying Issues of my bike.
(I sometimes use my index finger tipping at the front brake lever to avoid unintentional changes at throttle position at bumpy roads.)
 
#16 ·
I liked your review posts but this argument is obvious nonsense.

That I prefer the quietness of the gearbox of a Honda (or most other bikes) doesn't mean I would pick a Honda over the Scrambler. It's just one piece of a big puzzle. I would argue that most people don't think the clear cut gearbox sound is something nice or music to their ears. It's an annoying whistle.
Ducati doesn't have the best gearboxes, that's a pretty widely known fact.

If I tell you my Honda has a better seat than the Ducati, would you be proud to have a shitty seat because that makes it not a Honda?

Now the engine/exhaust sound itself is awesome, that's something most people can agree upon.
 
#15 ·
Ok! I got it:
It's not a bug, it's a feature! ;-)

Well, I think I have to find out, if my gearbox is louder than yours.

You know, I really love the Ducati Engine Sound! - And I'm simply interestet to hear more of it.
The noise of straight cut gearboxes is allways the same whatever motorsport equipment you have.
But, a Ducati V2 Engine...
 
#17 ·
He guys, can we agree that this special sound is also a matter of tast!
For me, I like it! but I didn't expect it to be that dominant. That's the whole story.

Monday in a week I'm going to have 1st service for the bike. we will see.
 
#18 ·
I have more Info. I just talked to the Head of our NVH/Drivtrain department (automotive)
He said that most bikes have staight cut gears. Only BMW has helical gears and some others like HD have high coverage teeth. So more teeth in contact leading to less noise.
 
#19 ·
Right I was probably a bit too aggressive in my earlier post. I can understand that some people might like this kind of sound. Matter of taste like you said.

BTW if someone wants to learn more about straight cut vs helical gearboxes, this post is helpful to know the pros and cons: Straight cut gears vs helical | Automotive Thinker - Discussing the finer points of automobiles

Basically helical cut gears are smoother, stronger and have a longer lifetime but are heavier and produce axial thrust. Straight cut gears like in many Ducatis are lighter, cheaper and lose less power but are noisy.
 
#21 ·
I returned my bike from the first service. - There is a change!
The gearbox 'sound' ;-) is now less dominant! I think it lowered about 1 to 2 dB.
I guess, that it's the different engine oil. - I am happy with that change!
 
#24 ·
noisy or not, at least yours shifts….

Just picked up a red Icon at the end of day Friday. By the time I got home(5 miles) It intermittantley took serious force to shift. I could still feel the lever imprint on the top of my foot ten minutes later haha. called the dealer immediately.. they were closing for the holiday weekend and said to go ahead and ride it and see if it breaks in. It has improved somewhat, sometimes it's as you would expect, sometimes it still doesnt want to go into the next gear. Its the inconsistancey that I find the most troubling and the thing that makes me think it could be seriously defective, not just tight. Has anybody else had this problem and had it resolved? I'm not a genius but I have owned bikes of all stripes(several Ducs) over 20 years of riding and this def is not a proper shifting bike.
 
#26 ·
Just picked up a red Icon at the end of day Friday. By the time I got home(5 miles) It intermittantley took serious force to shift. I could still feel the lever imprint on the top of my foot ten minutes later haha. called the dealer immediately.. they were closing for the holiday weekend and said to go ahead and ride it and see if it breaks in. It has improved somewhat, sometimes it's as you would expect, sometimes it still doesnt want to go into the next gear. Its the inconsistancey that I find the most troubling and the thing that makes me think it could be seriously defective, not just tight. Has anybody else had this problem and had it resolved? I'm not a genius but I have owned bikes of all stripes(several Ducs) over 20 years of riding and this def is not a proper shifting bike.
It shouldn't require that much force to shift. My red Icon shifts as easily as any of my other bikes and I could shift it bare foot if I had to. I get a nice klunk each upshift. Sixth gear sometimes feels more like a kah-chunk almost like a two stop shift, but the rest of em are smooth and easy. I haven't had a false neutral in the past 1000 miles.
 
#27 ·
Ya, adjusting the clutch cable was the first thing I tried, but it made no difference. Still, thanks for the suggestion. I appreciate it.
But…
I took it to the dealer today (on my trailer because i wasnt sure if I'd be dropping it off) and, of course, the bike worked as it should. Still just a a little stiff shifting, but if i wasnt hyper aware because of the earlier problems…I may not have thought anything about it. The mechanic rode it 2 miles and then i rode it to see if I could get it to act up, nothing. figures. But, I'm not complaining if the problem doesn't come back!
 
#30 ·
PS-Technik Teil 7 Getriebe und Schaltung - Motorradberatung - MOTORRAD

says:
...
Gentlest running in gears with helical teeth

The teeth of the gears are critical for the quietest possible running of the gear. Wherein the combination of pressure angle, addendum modification, module and tens of other factors is rather acted as a trade secret. The gentlest running unquestionably gears with a helical gearing. However, such transmission require an entirely different type of circuit, the power flow is produced not shift gears, but by so-called shift sleeves. The advantage of shifting sleeves: they can move extremely quickly and easily due to its light weight, which is why just laboring in racing with such transmissions. The drawback: The gear shafts build something longer than claw transmissions in which the complete gears are shifted.
...