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Discussion Starter · #1 ·
It's been a busy week and I haven't been able to really post anything about my trip out to Ohio yet!

This past Sunday I took a ride out from mid-NY to around Canal Winchester Ohio (Nearly 600 miles).
I went through 80+F temps, as well as thunderstorms. It handled wonderfully in the rain, the only issues I had were tar snakes, but those have always been one of my most feared enemies on a bike!
The whole ride was great, and my shoulders were fully recovered by early mid-week (instead of late in the week like my previous ride on a Silverwing).
The low-end power of this bike is amazing, which worked great for construction zones where I just let it roll along in 5th.

The only other thing I have to ask is what exactly is the whine coming from the bike?

:ty: Honda, for making such an affordable, and amazing bike!
 

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It's been a busy week and I haven't been able to really post anything about my trip out to Ohio yet!

This past Sunday I took a ride out from mid-NY to around Canal Winchester Ohio (Nearly 600 miles).
I went through 80+F temps, as well as thunderstorms. It handled wonderfully in the rain, the only issues I had were tar snakes, but those have always been one of my most feared enemies on a bike!
The whole ride was great, and my shoulders were fully recovered by early mid-week (instead of late in the week like my previous ride on a Silverwing).
The low-end power of this bike is amazing, which worked great for construction zones where I just let it roll along in 5th.

The only other thing I have to ask is what exactly is the whine coming from the bike?

:ty: Honda, for making such an affordable, and amazing bike!
Install a set of adjustable risers,, I did because of short arm syndrome... worked wonders and lets me sit back to take pressure off my lower back,, I expect it will also make my utopia back rest more comfortable this sunday
 

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Discussion Starter · #3 ·
Install a set of adjustable risers,, I did because of short arm syndrome... worked wonders and lets me sit back to take pressure off my lower back,, I expect it will also make my utopia back rest more comfortable this sunday
It's not the lower back that's the issue, it's right between my shoulders at the back of my neck.
 

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But I think you will notice an improvement there too, with a more relaxed sitting position where your arms are not stretched out in front of you .. If you are anywhere close to Maryland or anywhere near my path of travel starting Aug. 17th Glad to let you try mine out.. Doinf the USA 4 corners
 

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Maybe a bit of slouch happening? When I travel LD I usually have a drybag or two tied on the pillion and use that to lean back on. Don't really need anything for my back other than the stock seat bump for local riding. But always work at keeping my back straight. Sometimes I catch myself slouching and just the beginning of a very slight pain between the shoulders, but then straighten up and it goes away. I will also stretch my back (arching backwards while pulling shoulders back) while riding after a long time, and then stretch the other way slouching forward and repeat a few times and then I'm good for a long while without stopping.

The whine is the characteristic valve train whine that is normal with this engine. Many ST1300 owners have taken to really love this sound and consider it a distinction that sets their bike apart from others. Some refer to the overall sound of the ST1300 engine as a sewing machine sound. The CTX1300 changes this sound to a deeper, throatier sound (IMO) which I really like better than the ST. I was told by the ST group I camped with in June that the CTX sounds different than their ST engines while going down the road. They said this in a good way :D
 

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Discussion Starter · #8 ·
The whine is the characteristic valve train whine that is normal with this engine. Many ST1300 owners have taken to really love this sound and consider it a distinction that sets their bike apart from others. Some refer to the overall sound of the ST1300 engine as a sewing machine sound. The CTX1300 changes this sound to a deeper, throatier sound (IMO) which I really like better than the ST. I was told by the ST group I camped with in June that the CTX sounds different than their ST engines while going down the road. They said this in a good way :D
Thank you! I wasn't really complaining about the whine, just wondering exactly what it was from. Now I know what to tell people! (I thought it was the water pump or something.)
 

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Thank you! I wasn't really complaining about the whine, just wondering exactly what it was from. Now I know what to tell people! (I thought it was the water pump or something.)
did take it as complaining. But I do think it funny how so many ST1300 owners have such an affection for that whine. :)
Then again, most mc owners who love their rides do love the sound of those particular engines regardless what make/model it is. HD owners comes to mind at first, but other makes as well.
I like mine a lot :D
 

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But I think you will notice an improvement there too, with a more relaxed sitting position where your arms are not stretched out in front of you .. If you are anywhere close to Maryland or anywhere near my path of travel starting Aug. 17th Glad to let you try mine out.. Doinf the USA 4 corners
Definitely agree. ^^^ Risers that bring the bars closer to you will ease any shoulder and upper back pain.
 

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did NOT take it as complaining. But I do think it funny how so many ST1300 owners have such an affection for that whine. :)
Then again, most mc owners who love their rides do love the sound of those particular engines regardless what make/model it is. HD owners comes to mind at first, but other makes as well.
I like mine a lot :D
corrected... oops!
 

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The only other thing I have to ask is what exactly is the whine coming from the bike?
!
OK, coupla things: First off, hats off to everyone putting miles under the tires! I did 600 miles last Saturday, 427 miles on a day the previous week. I absolutely love this bike, and it makes the miles disappear. On that 427-mile trip, I was in a small town and a guy on a custom crotch-rocket pulled up beside me in the left lane at a stop light. We had been riding beside each other for a few miles. He was giving me compliments on my bike (yay!) and I reciprocated, telling him his was looking sharp. He told me he was out for a test ride, but kept hearing this whining sound, asked me if I heard it too. I said "Nope!" Then the light changed, and I twisted my wrist, and he looked up at me sharply and started lauging. "It's YOU! hahaha" And we both laughed as we took off. I love the sound of the CTX1300, not least for the fact that it sounds like no other bike. I think it sounds kinda like a spaceship. :)
 
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I don't think the whine on the CTX is quite as pronounced as I remember it on the ST. But it's very distinctive, and kind of suggests 'high-techiness'. And I got no problem with that. :)
 

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The whine is the characteristic valve train whine that is normal with this engine. Many ST1300 owners have taken to really love this sound and consider it a distinction that sets their bike apart from others. Some refer to the overall sound of the ST1300 engine as a sewing machine sound. The CTX1300 changes this sound to a deeper, throatier sound (IMO) which I really like better than the ST. I was told by the ST group I camped with in June that the CTX sounds different than their ST engines while going down the road. They said this in a good way :D
I know the whine is caused by the valve train, but what exactly makes this engine whine like that versus another engine? I have never heard that in a bike before so there must be some unique characteristic. I tell people it reminds me of a Ferrari.
 
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I know the whine is caused by the valve train, but what exactly makes this engine whine like that versus another engine? I have never heard that in a bike before so there must be some unique characteristic. I tell people it reminds me of a Ferrari.[/QUO

I got this info from another forum, and edited it a bit...

Honda is using straight cut gears here which do make more noise than angle cut gears. The trade-off is that the straight cut gears improve horsepower at the expense of noise. The angle cut gears provide less horsepower because they need a thrust washer on at least one side."

Straight cut gears offer the maximum efficiency and power transmission. Straight cut gears whine. Period. Ever hear a small block / big Chevy with a gear drive cam setup?

Not only is the clutch basket driven by straight cut gears, the engine balancers run straight cut gears. These gears are not immersed in oil as are the transmission gears, which are also straight cut. Therefore, you don't tend to hear the transmission, but you do hear the other straight cut gears which give the ST/CTX engine it's signature sound.
 

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Thanks! Interesting. I don't even know what straight or angle cut gears are, but that gives me some basis for research.
 

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Thanks for posting that link. Now I understand the difference. I always used to wonder about the street rods I would hear going down the street, whining away like that. It's all in the gears! Seems like as motorcycles all try to increase performance, more manufacturers would be using these. Granted, it dramatically changes the engine sound and wouldn't be a fit for Harley's signature sound or other cruisers, but I would think all the crotch rockets would use them.
 

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Here's a bit more insite into gear drive versus chain/belt drive cam systems.

There are several disadvantages to gear drives versus chain/belt drives for an overhead cam motor. It is a long way from the crankshaft to the cam(s), and since the cams rotate at ½ engine speed, sooner or later the gears have to be twice as big. Whenever you have a whole train of gears to contend with, the gear centers have to be fairly precise, or adjustable, to prevent rapid wear or failure. Since reducing/minimizing tolerances is always expensive, gear drive is going to cost more. Not so much because of the gear cost, although that is a consideration, but because you now have to establish and maintain fairly precise engine manufacturing techniques of all of the items that could affect the crankshaft centerline-to-camshaft centerline dimension. This would include the crankcases, the cylinders, the cylinder heads, and the gaskets. So you need precision in all of the casting and machining processes, as well as the assembly techniques. And since all this stuff is going to expand and contract as it heats up and cools down, it has to do it uniformly enough so that nothing binds or gets sloppy. Now the engineering cost has gone up. So simply from an economic point of view, chains or belts are easier to deal with, because they can be sloppier and still work well enough. Oh, and they are quieter.

There are two other items that get thrown into the mix here: crankshaft speed and valvetrain harmonics.

Crankshaft speed is not constant. A single cylinder 4 stroke engine is the worst, because it requires 720 degrees of crankshaft rotation to complete one cycle, and it is only making power for less than 180 degrees of crankshaft rotation. So the crankshaft rapidly accelerates to a maximum velocity in about 120 degrees of rotation, and spends the remaining 600 degrees of rotation decelerating. Typically a flywheel, which is simply a rotating weight, is added to the crankshaft to smooth out the acceleration/deceleration cycles. If the motor is small displacement and high-compression, and needs to run slowly, a flywheel is necessary just to keep it turning. The heavier the flywheel, the smoother the engine will run. The problem with a heavy flywheel is an engine will lose its ability to accelerate/decelerate rapidly.

Adding cylinders to a common crankshaft, in a fashion that staggers their power cycles with regard to each other, will make the crankshaft rotational speed more consistent. It still accelerates and decelerates, but at a higher frequency of occurrence.

On to valvetrain harmonics. This can be a bit trickier to explain without pictures, but here goes. Most 4 stroke engines use what is called a “poppet” valve to control airflow into the cylinder. They resemble a long, thin mushroom in appearance. The large end fits into a machined pocket in the combustion chamber, called a valve seat. The valve must be raised off the seat for air to flow past. It is raised off the seat mechanically by the action of a camshaft lobe. It returns to a seated position by a valve spring. The valve spring acts upon the “stem” end of the valve, and is mechanically retained. For most motorcycle engines made today, there is another piece referred to as a “bucket” (AKA “Cam Follower”) that goes in between the camshaft lobe and the end of the valve stem. That is where the shim lives that alters the mechanical clearance between the camshaft lobe face and the bucket. So technically, when you check “valve clearances”, you are really checking “valvetrain clearances”.

Anyway, here is where it gets interesting. Camshaft lobes are complicated little beasts. They have to take up the mechanical clearance as they open the valve, accelerate the valve as quickly as possible so air can flow, slow it down so the valve’s inertia does not allow it to lose contact with the lobe at peak lift, and then lower it as quickly as possible without letting it crash into the valve seat.

So, the camshaft rotates around to the point where the lobe is pushing down on the bucket/shim/valve stem, and is compressing the valve spring. Naturally, the cam wants to stop turning because the spring is resisting being compressed. As the valve opens further, the spring pressure rises and the camshaft resists turning even more. After peak lift is attained and the valve starts closing, the camshaft lobe is now being pushed upon by the valve spring/bucket, so it wants to speed up. So the typical valvetrain also accelerates and decelerates independently of the crankshaft.

All mechanical objects, and mechanical assemblies, have a resonant frequency, or harmonic. The classic example to use is spring with a weight attached to one end. You hold one end of the spring, and let the end with the weight attached drop towards the floor. The weight falls to a certain point, stops, and goes back up. It falls again but not as far, goes back up, etc, etc. That is the resonant frequency of that assembly. There is more associated with this topic, but I’m sure entire books are dedicated to it. The point here is that all things freely vibrate at some rate of occurrence.

All resonant frequencies can be altered to some extent. Think of a guitar string at a particular tension. You strike it, and it freely vibrates. Change the tension on it and it still vibrates, but at a different frequency. Make the string thicker or thinner, longer or shorter, and the harmonics will change.

A whirling crankshaft, with connecting rods, pistons, piston rings and associated bits and pieces, has a resonant frequency. A valvetrain has all kinds of wonderful harmonics associated with it, particularly a valvetrain with mechanical clearances, springs, and fairly radical camshaft lobes. In both instances, every individual piece has a resonant frequency, the immediate combined parts have a resonant frequency, and the entire assemblies have a resonant frequency. As long as none of the resonances combine at some point that exceeds the molecular bonding strength of one of the items, all is well.

Where is this whole mess going? When you directly couple the crankshaft to the valvetrain with mechanical gears, you have directly coupled all of the mechanical disturbances together. A chain or a belt offers some damping, or isolation, from these disturbances. The flip side of this argument is that you want your valvetrain events to coincide exactly with the piston/crankshaft location so that all cylinders produce the same output (hopefully maximum).

When automotive engines started using chains to drive the camshafts, they were “net fit”, as in there was no way to take up the slack. The chains just stretched and got sloppy, and whipped around a lot. Unless there is some sort of dynamic tension adjuster on a belt or chain drive, they will whip around as they warm up, in a somewhat unpredictable fashion. This will cause fluctuations in the valve timing events in one cylinder or multiple cylinders.

The good news is that materials, and understanding of engine/valvetrain harmonics, have come a long way. Most of the afore-mentioned harmonic considerations are high RPM problems, but then again we now live in a world of 16000 RPM 600cc motors, and 12000 RPM 1000cc motors. And what do the Formula 1 motors do now? 20000 RPM? Of course, they have pneumatically controlled valvetrains...

So ultimately, it could be said that gears offer potentially higher performance due to the more closely controlled timing events necessary for maximum output, but they will cost more, in general, to produce and reliably engineer.

Ow, my fingers hurt...
 
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