Can someone talk about the db's?

[ReTodd]

I think the bikes are an exciting addition to the sport. I'm excited to try one. However, sitting on Sale Mt in Revy last winter listing to the resonating noise of one across the entire valley riding Frisby, it occurred to me that those suckers are loud and we are already on thin ice with the Boo huggers. Yes, some sleds have loud pipes, but the pipes are muffled by pointing down and the 8k rpm 2 stroke does not resonate the same as a 4K rpm 4 stroke.

It is easy to imagine a day soon where individual clubs have to have DB sensors at the pay booth and 99% of the bikes wouldn't pass.

Has anyone designed a pipe that has a turn down instead of the standard straight back design?

 

[Popik]

I would think the DB's from a chopper whipping around would be much worse and they don't seem to take any flack from the greenies

 

[AK1000]

When we rode revy/boulder this spring there was three of us on bikes and two on sleds and you could lose the noise from either only one bowl or hill over. Both seemed quiet enough from a small distance, seems it could be an issue but most bikes are set up close to factory db and they are approved for forest service area i guess. Would like to avoid the issue if possible but depends where you ride i suppose.

 

[capulin overdrive]

Meh, most sleds are louder and take more rpm just to get them moving. Putting around in the trees, we ain't making much noise.

 

[wwillf01]

If you keep the exhausts packed right they should be good... they have to meet the standards for racing.


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[needpowder]

The sound of a 4 stroke carries much further. It's not at all the same as a 2 stroke.

 

[needpowder]

I would think the DB's from a chopper whipping around would be much worse and they don't seem to take any flack from the greenies

In my neck of the woods the greenies hate the chopper almost as much as they hate the sleds.

 

[M5-]

The greenies hate everything with the exception of their wood framed houses and electricity gobbling Prius'.

M5

 

[Teth-Air]

They sound way better than a Harley and at least they are in the back country where they bother way less people.

 

[boondocker97]

Article from when AMA adopted the 94db limit for competition bikes in motocross and supercross: http://motocrossactionmag.com/uncategorized/ask-the-mxperts-what-will-happen-with-the-new-94db-ama-sound-limits

So judging by this, most factory bikes are probably 95db or so at 4000rpm. Very few riders regularly repack silencers, if ever, unless they are being sound checked at races. As much as I hate it, I kinda wish game wardens and forest service would do more sound checks on all OHVs. Enforcing sound restrictions that are in place is a lot better than just shutting an area down.

 

[CATSLEDMAN1]

noisy bikes

a couple of snowbikes in an area will drown out ten stock mtn sleds as far as noise. WAY NOt GOOD, I have sat looking down a 4 mile long snowy canyon and could hear one bike coming, when then show its 5 sleds and one bike.

I put three different mufflers on my WR, last FMF mufffler was just ok.
For sure pointing the exhaust down at the snow would help a lot.
Embarrassing how loud a stock bike out on the snow can be. Its an issue and will become a bigger issue.

 

[Dam Dave]

Motocross 4 strokes are just flat loud, off road bikes are rated lower db, Colorado has a db law for anything used on public land

 

[Hawkster]

A two stroke bike has nothing on a four stroke when it comes to being obnoxious , there's a motocross track about a mile away over the hills and threw the woods and as long as there is a thumper on the track I can not hear a two stroke .

As far as the hogs go , does anybody remember when the Harley tariff was passed threw congress ? It was a tariff on any foreign bikes bigger than a 750 which they quickly retooled and started producing 700s' . While at the same time Harley was climbing out of the hole they dug they where also using Kawasaki frames . The serial # starts with a KZ on the bottom side of the frame . They also sicked the dogs on the crotch rockets claiming their exhaust was to loud giving reasonable cause to pull them over . Don't get me started on their over bored illegal super bike with a Czech made engine back in the 90's or what they did to Erik Buell .

Anyway , how many of you guys are even running a spark arrestor ? If I'm not mistaken does that not also change the Db ?

 

[Wheel House Motorsports]

aside from the ramblings of everyone about whether it matters or not... haha

best bet is to get the exaust turned down. Sleds point at the snow which helps a ton for keeping the sound down. Bikes, pointed sky high echoing across the valley. A custom muffler tip with a turn down to help at least better direct the sound would probably help a ton. I would like to throw something together and see if I can make my bike a little less horrible.

But, like some mentioned, keep the muffler packed. I know that when your WOT all day they blow out very fast and you dont realize how loud your bike is until you hop on one with a fresh slip on.

 

[Red Mtn]

As much as I hate it, I kinda wish game wardens and forest service would do more sound checks on all OHVs. Enforcing sound restrictions that are in place is a lot better than just shutting an area down.

So you want to be regulated by the cops? That is crazy!


The more you appease the bully, the more bold he becomes.

 

[n16ht5]

I keep my spark arrestor in, it gets too loud without it. someone needs to make a tunnel dump pipe with an insulated hot dogger attachment

 

[Popik]

I keep my spark arrestor in, it gets too loud without it. someone needs to make a tunnel dump pipe with an insulated hot dogger attachment

So much yes to this. The only thing i think i will miss on my sled this year when on the bike is my cooker can haha

 

[eric82930]

No doubt the 450's are a bad sound for our sport. I have been back and forth between 2 and 4 for a decade on dirt and snow. I really wish the 450's weren't so dang loud. On my 505 xcf I welded a 45deg elbow on the outlet to turn the flow down and slightly to the side to miss my aux fuel tank. I did back to back testing with a stock xcw muffler (spark arresstor but no elbow) and the xcf muffler (straight through with elbow) was lighter, quieter and better performance. Snow makes a good muffler and directing the sound pressure waves towards the snow really helps.

Ever notice how loud a sled gets when they wheelie over a cornice and stand straight up? Its a huge difference.

The only downside to a dorky elbow exhaust is resale value. When I sold the 505 I had to put another muffler on it.

 

[boondocker97]

So you want to be regulated by the cops? That is crazy!


The more you appease the bully, the more bold he becomes.

The laws are already in place and enforceable by those entities. They just don't do it very much. I'm saying I'd rather have them enforce the laws that are on the books and bring the tone down a bit rather than be kicked out of riding areas.

 

[Rush44]

You need to repack your mufflers EVERY season (I've repacked mid-season before) and it makes a very noticeable difference.... especially with the popping at high RPM or decel. Very noticeable difference. By far an away FMF appears to be the loudest common aftermarket out there. Pro Circuit T5/T6 has a much deeper quieter noise... it's worth the extra money (plus it's just plain built better).

However, nothing on the planet is worse than a blown out KX450 stock exhaust. It is the most annoying 4 stroke bike sound on earth. A beat up YZ exhaust is a close second.