Replacement exhaust system increased vibration - Honda CBR250R Forum : Honda CBR 250 Forums
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post #1 of 24 Old 06-02-2014, 08:01 AM Thread Starter
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Replacement exhaust system increased vibration

Hi there, I have just installed a new Delkevic 450mm long exhaust and I am experiencing increased vibration levels through the seat and rear grab handles. (I would hazard a guess this is why the standard exhaust is a heavy item to adsorb the secondary vibration from the engine)

I have loosened all the clamps and set the position of the slip-on several times with the same result.

Has anyone experienced bulb, battery of computer related failures from vibration, when fitting a replacement slip-on or full exhaust?
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post #2 of 24 Old 06-02-2014, 08:58 AM
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Many cheap exhausts are not packed properly and need doing straight away.

If it sounds raspy and not deep its a sure sign its not absorbing the resonance (is that the correct word?)




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post #3 of 24 Old 06-02-2014, 09:22 AM
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Someone should do a thread on repacking an exhaust, if it hasn't been done already.
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post #4 of 24 Old 06-02-2014, 09:24 AM
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Quote:
Originally Posted by Dalap View Post
Someone should do a thread on repacking an exhaust, if it hasn't been done already.
Ive already done one (click my profile)




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post #5 of 24 Old 06-02-2014, 11:16 AM Thread Starter
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The exhaust properly wont have packing, there is a central perforated tube that runs the length of the can (this is normally wrapped in packing), however the DB killer is a 250mm tube with a round dome on the end (rather like a bell end), when this is inserted into the exhaust it effectively separate the can into two parts. Exhaust enters the end of the can and is forced through the perforated tube into the outer can and then re-enters the perforated tube to exit the exhaust. If there were packing the exhaust would effectively be blocked when the DB killer (baffle) was inserted.
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post #6 of 24 Old 06-03-2014, 12:18 AM
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stock exhaust is heavy for other reasons..
honda wouldnt choose to place a heavy weight
on one side rear 'to reduce engine vibrations'..
my lv slip-on produces zero vibrations at
its mounting point, never mind further
up potential vibration pathways..

something isnt right..
first thought damping at mounting points,
such as rubber around cannister and
between mount and mounting bolts..

probably wouldnt hurt to contact manufacturer,
could be something simple known to them..
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post #7 of 24 Old 06-03-2014, 06:44 AM Thread Starter
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Mounting rubbers all good, i think it maybe because its the longest (quietest one they do @ 450mm long), the end of the slip-on is oscillating as the mount bracket is on the first 20% of the pipe and needs to be in the middle. I am going to remove it for the time being and contact the manufacturer for there opinion.
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post #8 of 24 Old 06-03-2014, 09:53 AM
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Quote:
Originally Posted by lemmy99 View Post
The exhaust properly wont have packing, there is a central perforated tube that runs the length of the can (this is normally wrapped in packing), however the DB killer is a 250mm tube with a round dome on the end (rather like a bell end), when this is inserted into the exhaust it effectively separate the can into two parts. Exhaust enters the end of the can and is forced through the perforated tube into the outer can and then re-enters the perforated tube to exit the exhaust. If there were packing the exhaust would effectively be blocked when the DB killer (baffle) was inserted.
It's hard to believe that an aftermarket can wouldn't have some kind of packing material... if that's true, it would certainly explain the increased vibrations.

Former Factory Test Rider/Technician
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post #9 of 24 Old 06-03-2014, 06:01 PM
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That's strange I have the exact same one. Mine is the 450 mm stainless steel version. I don't have any weird oscillation at the end or more increased vibration. Just a deep rumble. After a little over 2k miles on it still great. I think with smaller companies the QA is always gonna be hit or miss. Just an observation, though.
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post #10 of 24 Old 06-03-2014, 06:37 PM
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oscillation should indicate movement both sides of
its mounting strap/nut, provided the strap/nut and
its mounting point [footpeg bracket] are solid..
header pipe if undisturbed should be solid,
leaving midpipe attachment suspect..

on mine [lv] midpipe is welded at cannister
and was a good tight fit to end of header pipe..
ie, no potential for movement required for
oscillation..

manufacturer will ask if header pipe and
footpeg bracket are solid and secure..

even without packing etc it should not
oscillate, provided good fit and mounting..

Last edited by shisoshin; 06-03-2014 at 06:39 PM. Reason: typo
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