shhh... quiet: db snorkel, monster silencers, quiet exhaust

when i was young, i loved loud. my YZ490 was only quiet in comparison to my RZ350. (2 stroke loud... still doesn't carry vast distances like loud 4 strokes)

now, i like land use, not scaring the crap out of my kids when riding with them and preserving what hearing i've got left.

i've not been terribly impressed with the Q stealth & i'm a cheap bastid... plus i like building things. with that in mind, i'm thinking of re-purposing something along the lines of a hockeystick or starting from scratch (i've got a metal shop & weld/fabricate). i know wrapping the pipe helps, as well as all the rattle/resonant noise elsewhere on the bike... but looking at silencers at the moment.

care to have a silencer discussion?

FWIW, I understand DB Snorkel is out of business and has been for quite some time. The operation was for sale. I have one (a DB Snorkel) and it is effective. Made my KTM 300XCW sound like a stock KDX200. Took a bit of juice off the top end; but not much. FMF is so into less sound=more ground you would think if the DB system was viable they would have capitalized on it.



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yeah; I talked to the owner (at the time) of DB Snorkel... right about the time they ceased sales due to production costs. I had one & should have kept it. Found it to be reasonably effective.

the FMF Q stealth seems good at low RPMs but doesn't seem (to my ears) to do much for sound reduction at higher RPMs. maybe a sound tech will chime in.

I used a Supertrapp on the end of my Yamaha TY-175 stock pipe.

It was so quite that I could ride right up behind hikers on the trail and they ride not know I was then until the last 25 feet.

I have been thinking of doing the same on my IT465.

came across this on an old post on a 2T forum... no details that i could find other than a bloke built it for a CR500 with "great results"

most of the low RPM noise from my IT250 comes from the jug... brand new elastomeric absorbers (those rubber things jammed in the fins of the jug & head) helped.
i also temporarily used a 2.5' long, 3" diameter silencer... 1" perforated core. it was quiet, but had the same effect as a loooong stinger and was a proper bitch to jet.

on air cooled bikes, i lower noise with rubber tubing jammed in between the fins. ringing can also be reduced by wrapping some inner tube around the cylinder fins- helps pass db tech :)

a good flexible seal at head pipe to cylinder joint also reduces noise greatly..

That thing is huge.

I would love a DB snorkel if I could get my hands on a used one. Not that I'm riding anywhere illegal or anything, but a quiet bike would great.

hehehehehehe....
oh, the silencer in the drawing. yeah.

i had one and loved it. it sold with a bike... wasn't thinking that it'd be so difficult to get another one. i'm not riding anywhere illegal (prove it!), just really like having legal areas to ride in... the less noise i (and we all) make, the less people get pissed off, and the less land that gets taken away.

How do they affect the power curve of a 2 stroke?

DB Snorkel? supposedly no difference...
i didn't notice anything, but it was on a big bore and it'd still have ripped towing an anchor...

That looks pretty good dhallilama. Very similar to the stocker on my 490 GS, which makes it VERY quiet.

Yup...very quiet and I don't feel any power loss on the 500. Can't speak for the smaller bikes though.

mmmmmmmmmmmmMaico.... that's a purdy bike right there!

i'm thinking of building a silencer like that... maybe play around with the dimensions a little. is the Maico silencer re-packable?

On my 200, it was terrible. Ran fine at low rpm, but on the first stretch of gravel road it wouldn't rev, overheated and pushed the crank seal out. Took it off and it ran better but burned a little tranny oil, at least until the crank seal finished working its way out.

Worked perfectly on my trials bike, though. I just took it off because it was too bulky and replaced it with a little turn-down tip.

BTW, the little turn down tip made a huge difference. It was just a 90* plumbing bend the same diameter as the pipe outlet. Part of the benefit was that the outlet was now pointed 45* down instead of 45* up. I think going from 1" to 5" or so of outlet length helped a lot too.

No packing. Welded shut. Thanks. It's a low hour original.

Yup...turn downs work well.

while not motorcycle related, for a couple decades Volvo used an S bend after the muffler (a pair of ~90 degree bends), to lower noise output. worked well.

Do you have a picture of the SuperTrapp configuration you mentioned? I'd like to emulate. thx