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Old 7th April 2014, 22:51   #301
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Default Re: GoldStar Silencer

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Originally Posted by csubhojit View Post
I am a newbie and a proud owner of a new RE Classic 500cc. This is my first bike (yes you heard it right) and while I am loving it, am also having a few experiences which, if helped out with, will help this poor soul a great deal.

When I ride it in the city (with moderate traffic), my right hand goes number after some time,



.
Congrats on the Bullet.
Why dont you start by wearing gloves? A much easier and cheaper option.
The vibrations on a free flow is low , but at higher rpms.
I dont think the vibrations should be that bad to numb your palm.
Try varying rpms while riding to check if the vibrations are the same all over the bike.
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Old 7th April 2014, 23:07   #302
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Default Re: GoldStar Silencer

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Congrats on the Bullet.
Why dont you start by wearing gloves? A much easier and cheaper option.
The vibrations on a free flow is low , but at higher rpms.
I dont think the vibrations should be that bad to numb your palm.
Try varying rpms while riding to check if the vibrations are the same all over the bike.
Thanks Tharian. I did indeed get gloves. The vibrations are more at lower rpms gears right now which I think is expected as the engine settles during the run in. Again it more during traffic when I am riding around 10-20kmph and most of the time on 2nd.

Thanks all the same!

Regards,
Subhojit
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Old 8th April 2014, 02:55   #303
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Default Re: GoldStar Silencer

csubhojit
Noise and vibration are not directly related.
It is possible that changing the exhaust silencer may have an effect on vibration though.

The OEM silencer is, as you know, rather large and heavy. Everything has some frequencies that stimulate them causing them to shake and a heavy item will be affected at low frequencies like those produced by a big single at low speeds.

That said, I can't say the weight of your OEM silencer is the cause of the vibration you are experiencing. It is more likely caused by your new engine vibrating. Royal Enfields seem to vibrate more during their early break in period than they do after they have several thousand Km on them. As the parts wear in with their mating parts, they just seem to run smoother.

Another source of vibration on the Royal Enfields can be a loose "head steady" or engine mount bolts. Have your mechanic check the engine mount bolts and the "head steady" bolts for tightness. They should be torqued to 50 N/M.
The "head steady" occasionally will be found to have cracked and if this happens the entire motorcycle will vibrate.

The head steady is the bar that is located at the top rear of the engine cylinder. It connects to the rear mounting bolt for the fuel tank.

Another source of hand numbing "caused by vibration" is not really caused by vibration at all. It is experienced by some new riders who grasp the handlebar grips with a death grip to keep the bike under control.
There is no need to grip the handlebars tightly and if you are doing this, try just lightly resting your hands on the bars. It takes a very light grip to totally control the machine under all conditions.

I, for instance ride with my right hand gripping the throttle with my thumb and my little finger and the finger next to it. It's index finger (next to the thumb) and middle finger extend over the front brake lever.

My left hand grasps the left grip in the same manner with the index finger and middle finger extended over the clutch lever.

With my fingers so arranged, applying the front brake and the clutch in an emergency is nearly instantaneous and because both hands are lightly gripping the handlebars, numbing caused by vibration is never a problem for me.
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Old 8th April 2014, 08:55   #304
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Default Re: GoldStar Silencer

Thanks a lot Arizona. I will definitely ask my mechanic to check the bolts and the head steady bar which you mentioned.

However, I have a feeling that this has more to do with the new engine and my grip. Like I said, this is my first motorcycle. It was a dream but I was scared when I rode it the first time. I have always heard people say how a RE is solid metal, etc and it had an effect on me. Even though I now feel that this is by far the safest two wheeler I have ridden, but I guess I will have to work on my grip. Like I said, the vibration is felt more during lowers rpms and when I am driving at very slow speeds. I guess I must be gripping the right hand grip very tightly in the fear or losing control over the bike. I just need to be a bit more conscious.

Thanks a ton!
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Old 22nd April 2014, 20:57   #305
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Default Re: GoldStar Silencer

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Originally Posted by ArizonaJim View Post
The glasswool is the sound deadening material and it can be used in straight thru or baffled silencers depending on who made it and what their design is.

In your OP, you indicated a loss of power at high rpm's and this usually indicates a restrictive exhaust system.

That is the reason I mentioned the possible presence of baffles which were blocking the high rpm exhaust.

As you indicate the silencer which seemed to cause the problem is a straight thru design obviously baffles are not the problem.
That does not rule out a restriction being created by some other factor.

Air moving at high velocities can, under certain circumstances create shock waves of high pressure gas. If this happens the zones of high pressure gas can become restrictive to the free flow of the gas thru the tube.
This is sometimes caused by louvers pierced and formed thru the inner wall of the tube. There are other configurations that can also disturb the airflow.

In any case, it sounds like your Goldstar, for whatever reason is restricting the exhaust flow.

As you already know what your Goldstar is doing perhaps trying one of the baffled designs would be worth investigating although I would be the last person to suggest just throwing money at the problem.

Have any of you other readers tried a similar Goldstar on your Royal Enfield and seen similar results? Your input could help shan2129 decide what his next move is.
Hi Jim,

I did change the Muffler to a Goldstar with baffles ( 2 baffles inside ) & to my surprise, the overall feel of my bike is much better. Now it actually feels like a 500 ( I did try higher speeds & got there successfully ). So, it seems as if the free flowing goldstar with glasswool is not suited for my Bull. Lesson learnt, thump is not everything

Thanks for all your help
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Old 23rd April 2014, 12:41   #306
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Default Re: GoldStar Silencer

You know I have been thinking about the freeflow/goldstar mufflers and why most ppl install it.
Most people install it for sound ... right?

I did a though experiment (backed by actual observations): the sound of engine (at the same RPM) changes drastically with the load imposed on it.
Which means say you are on a decline slope, and ambling down at 1500 RPM.
Compared with put-putting on an incline, but again at the same RPM (1500).

The sound would be louder in case of incline because the engine generates greater torque (even though it is at same RPM=1500) because a greater load is imposed on the engine while on incline vis-a-vis the decline.

Shouldn't the exhaust sound be louder if there is more obstruction in the flow of exhaust gases compared to a free flow? More obstruction = more demand on the engine (similar to the case above).
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Old 23rd April 2014, 16:35   #307
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Default Re: GoldStar Silencer

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Originally Posted by alpha1 View Post
You know I have been thinking about the freeflow/goldstar mufflers and why most ppl install it.
Most people install it for sound ... right?

I did a though experiment (backed by actual observations): the sound of engine (at the same RPM) changes drastically with the load imposed on it.
Which means say you are on a decline slope, and ambling down at 1500 RPM.
Compared with put-putting on an incline, but again at the same RPM (1500).

The sound would be louder in case of incline because the engine generates greater torque (even though it is at same RPM=1500) because a greater load is imposed on the engine while on incline vis-a-vis the decline.

Shouldn't the exhaust sound be louder if there is more obstruction in the flow of exhaust gases compared to a free flow? More obstruction = more demand on the engine (similar to the case above).
I guess your mixing up the engine note and exhaust notes.

Engine note works like you said- it varies according to the rpms.
The exhaust note again depends on rpm, but it does not get louder because the exhaust system has obstructions in it. The obstructions are there to cancel out the sound waves.
Neither does it put a great pressure on the engine like climbing a hill for the engine to sound louder. It does work a bit harder with a baffled muffler in the sense that the engine has the additional work of pushing out the backpressure exhaust along with the fresh exhaust gas when compared to a free flow, which is why you get more low end torque out of a stock exhaust when compared to a free flow.

On a multi-cylinder engine or a big single engine, a well made FFE is always healthy for the engine provided the engine is not revv'd just for the sound.
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Old 23rd April 2014, 18:01   #308
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Default Re: GoldStar Silencer

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Originally Posted by tharian View Post
I guess your mixing up the engine note and exhaust notes.

Engine note works like you said- it varies according to the rpms.
The exhaust note again depends on rpm, but it does not get louder because the exhaust system has obstructions in it. The obstructions are there to cancel out the sound waves.
Neither does it put a great pressure on the engine like climbing a hill for the engine to sound louder. It does work a bit harder with a baffled muffler in the sense that the engine has the additional work of pushing out the backpressure exhaust along with the fresh exhaust gas when compared to a free flow, which is why you get more low end torque out of a stock exhaust when compared to a free flow.

On a multi-cylinder engine or a big single engine, a well made FFE is always healthy for the engine provided the engine is not revv'd just for the sound.
The engine note that we hear IS the exhaust gases only. The power cycle happens under closed chamber - thus doesn't produce the explosive sound - but when these gases come out of the outlet valve and expand rapidly in the exhaust system - it creates the bang/potato-tato/phat-phat, etc.
It is this sound which is conveyed to outside world via the exhaust gases. the gases once outside the cylinder don't have any means of generating further sound.

Not much different from a gun. The sound is produced by rapidly expanding gases in the muzzle - which gets conveyed to the outside world via the outlet.

The suppression can be done by using glasswool (which absorbs sounds waves -especially the higher frequency component- that's why glass wool silencers sound bassy) OR baffles - which utilize reflection of sound waves to create destructive interference of soundwaves. These baffles do not really hinder the flow of exhaust gases (OK they do to some extent).

What I am talking about is entirely different. Using an obstruction in the path of exhaust gases but not to cause the destructive interference, BUT to create a back pressure.

What basically I would try to achieve is that the engine creates more torque to counter the resistances (vehicle moving as well as the exhaust gases) which will cause it to run louder. Thus the exhaust will also sound louder.

Last edited by aah78 : 23rd April 2014 at 18:51. Reason: Post edited on request.
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Old 23rd April 2014, 18:21   #309
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Default Re: GoldStar Silencer

I picked up a Indimotrads thumper exhaust. Its made of Aluminum and weighs lot less as compared to the stock. Noticeable increase in performance. Here is a short video of it on my 9 year old Tbird.


Last edited by adityasiera : 23rd April 2014 at 18:23.
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Old 24th April 2014, 08:47   #310
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Default Re: GoldStar Silencer

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Originally Posted by alpha1 View Post
The engine note that we hear IS the exhaust gases only. The power cycle happens under closed chamber - thus doesn't produce the explosive sound - but when these gases come out of the outlet valve and expand rapidly in the exhaust system - it creates the bang/potato-tato/phat-phat, etc.
It is this sound which is conveyed to outside world via the exhaust gases. the gases once outside the cylinder don't have any means of generating further sound.

Not much different from a gun. The sound is produced by rapidly expanding gases in the muzzle - which gets conveyed to the outside world via the outlet.

The suppression can be done by using glasswool (which absorbs sounds waves -especially the higher frequency component- that's why glass wool silencers sound bassy) OR baffles - which utilize reflection of sound waves to create destructive interference of soundwaves. These baffles do not really hinder the flow of exhaust gases (OK they do to some extent).

What I am talking about is entirely different. Using an obstruction in the path of exhaust gases but not to cause the destructive interference, BUT to create a back pressure.

What basically I would try to achieve is that the engine creates more torque to counter the resistances (vehicle moving as well as the exhaust gases) which will cause it to run louder. Thus the exhaust will also sound louder.
Okay, got it. I thought you were talking about the engine clatter when you spoke about engine note.
To understand what you are saying better , you had mentioned that you had a done an experiment and noticed that the sound does increase when there is an obstruction in the pipe apart from the usual baffle, could you tell me what that experiment was?

I am asking since, from what I have experimented and read till date, it tells me that a free flow will always be loud compared to an obstructed exhaust. The glasswool like you said will absorb a certain frequency and leave the bass out, so at the end when you rev the engine, the glasswool exhaust which is free flow will be still louder than a baffled muffler.

There is once instance which I can relate to what you have said in which the muffler although baffled , is as loud as a freeflow with glasswool stuffed fully.
The freeflow is on my CI500 and a stock short bottle wide mouth(from the old 500) Bullet muffler fitted onto the short bend pipe of a CI350 5sp and boy is that loud . I am not sure if it is the tuning, but for a 350, the note is quite loud and gets better as the revs increase. One reason for this can be that inlet and exit holes in the chamber are bigger than the usual , because it was made for the 500. But they are still chambered with filtered pipes in them. But, remove the glasswool from the 500 CI and the 350 will never be heard.

Last edited by tharian : 24th April 2014 at 08:48.
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Old 24th April 2014, 12:01   #311
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Default Re: GoldStar Silencer

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Originally Posted by tharian View Post
To understand what you are saying better , you had mentioned that you had a done an experiment and noticed that the sound does increase when there is an obstruction in the pipe apart from the usual baffle, could you tell me what that experiment was?
Observation and thought experiment
No real experiment till now.

I have free flow Goldie shaped glass wool packed muffler on my AVL. Let's see if I really do some experiment.
But to be open, any obstruction in the path of exhaust will load the engine higher, thus perhaps making it sound louder, but also increasing the fuel consumption and reducing the maximum torque available at the wheel.

Though it can also be that the obstruction in the flow causes a constructive interference pattern and THAT makes it sound loud - not the increased load on the engine. Anyway I am just speculating here.
Quote:
There is once instance which I can relate to what you have said in which the muffler although baffled , is as loud as a freeflow with glasswool stuffed fully.
The freeflow is on my CI500 and a stock short bottle wide mouth(from the old 500) Bullet muffler fitted onto the short bend pipe of a CI350 5sp and boy is that loud . I am not sure if it is the tuning, but for a 350, the note is quite loud and gets better as the revs increase. One reason for this can be that inlet and exit holes in the chamber are bigger than the usual , because it was made for the 500. But they are still chambered with filtered pipes in them.
This is the exact reason why I started thinking on the lines. The bottle silencer (old Bull muffler) sounds the loudest. Louder and better than my free flow.

(of course the Rocket "silencer" sounds the loudest - but that is plain racket)

Quote:
But, remove the glasswool from the 500 CI and the 350 will never be heard.
Hahaha, I have already mentioned the racket produced by the rocket!

I have had the pleasure of having used the following silencer till now:
1. stock TBird (mine is 2003-04 era): sounds like Singer sewing machine
2. bottle silencer of CI 350 bull: sounds loud and sharp
3. rocket silencer: racket! very mid rangey
4. goldie shaped glasswool: bassy but doen't have the sharpness of the bottle

By the time I came to goldie, I had paid the fabricator and thus kept it.

Last edited by alpha1 : 24th April 2014 at 12:13.
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Old 10th February 2015, 10:58   #312
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Default Re: GoldStar Silencer

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Originally Posted by alpha1 View Post
I have had the pleasure of having used the following silencer till now:
1. stock TBird (mine is 2003-04 era): sounds like Singer sewing machine
Hi Alpha1,

This is the sound (Singer sewing machine) I have always wanted in my bullet. I own a TB 350, (Sep'2014) and have done 800 KMs. I do not want to change the stock exhaust pipe immediately but for future once I have done about 2-3k kms; could you suggest how I can get the Singer sewing machine sound?
----------------
Also, I have noticed that my bike sounds quite well when started from cold but as the engine heats up (say after driving for 6-7 KMs) and if I rev hard, the sweet/meatier sound disappears and it sounds more like the yezdi of 80s. Also, the sound changes when I go double ride perhaps due to the the load on the engine that you spoke about.

Many thanks.
Sanjay
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Old 10th February 2015, 17:46   #313
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Default Re: GoldStar Silencer

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Hi Alpha1,

This is the sound (Singer sewing machine) I have always wanted in my bullet. I own a TB 350, (Sep'2014) and have done 800 KMs. I do not want to change the stock exhaust pipe immediately but for future once I have done about 2-3k kms; could you suggest how I can get the Singer sewing machine sound?
I am not aware of the new muffler that comes with new TB, but the old long cigar shaped one that came with TB (2003) used to sound very very soft. (which is what I described by saying singer sewing machine - all that came out was the 'kach kach' sound of tappets and pushrods)

Last edited by alpha1 : 10th February 2015 at 17:48.
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Old 11th February 2015, 09:42   #314
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Default Re: GoldStar Silencer

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Originally Posted by alpha1 View Post
I am not aware of the new muffler that comes with new TB, but the old long cigar shaped one that came with TB (2003) used to sound very very soft. (which is what I described by saying singer sewing machine - all that came out was the 'kach kach' sound of tappets and pushrods)
I acquired a mint condition AVL Tbird 350 2004 model last year in feb around the same time. I bought it especially for touring as I found it more comfortable than my existing three Standard CI 350's. The sound that you have defined is very true, it does sound like a singer sewing machine. This very sound made my long rides comfortable and easy. Note that the earlier owner had changed the factory fitted bazooka silencer to Electra short bottle of that era but the sound still remained like a well oiled sewing machine. I have mentioned elsewhere on some other thread that loud exhausts are only good for city riding. Once you are on the highway riding upwards of 80 KMPH and covering about 300 Kms that very loud sound becomes annoying and wears you out. Besides one's ears start ringing and goes numb after a mega long ride. I somehow like the soft sound of my AVL Tbird 350 (2004), this is exactly the reason why I haven't changed my brand new Tbird 500's silencer.
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Old 11th February 2015, 13:48   #315
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Default Re: GoldStar Silencer

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Originally Posted by navin_v8 View Post
. loud exhausts are only good for city riding. Once you are on the highway riding upwards of 80 KMPH and covering about 300 Kms that very loud sound becomes annoying and wears you out. Besides one's ears start ringing and goes numb after a mega long ride. .
Exactly my experience. I too prefer the silent OEM exhaust. I tried the RRP exhaust it was too loud on the highway. In the city the RRP did activate the car alarms in my neighbourhood. I switched back to OEM immediately.

Last edited by adnaps : 11th February 2015 at 13:51. Reason: Correction
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