swampy
Moderator
Registered: 02/16/06
Posts: 6,814
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| | 08/20/07 | Reply with quote | #1 |
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(This information Is Also Available On the http://www.dixiedualsport.com website)
For Any DDS Event, Here's What We Expect:
No Race Numbers
Dual sporting is a recreational riding event, not a race. Since the general public already thinks that a dual sport motorcycle is a "dirtbike", imagine what they think when a bunch come off the trails and roads loaded with numbers and race stickers on them. Not a good impression for the sport! Remove them prior to tech inspection.
Working Lights, Mirror.
Dual sport is STREET LEGAL. That means the vehicles have to be street legal. Hence, the difference between dual sport and off-road vehicles. Imagine during an event a person gets pulled over and they do not have the proper equipment on their bikes. What does this mean to the promoter who must apply for special event permits on public lands and explain to the USFS or State Agencies why the people participating on open roadways have illegal bikes. How long do you think they will still issue those special use permits?
License Plate (Tag) Firmly attached (bolted) to the motorcycle.
Once again, we're talking street legal. It is not legal to have a tag strapped to your chest protector. Once again see the paragraph above. Promoters have to jump through a lot of hoops to obtain special use permits, and riders like to ride. It's not too much to ask that you bolt your tag onto your bike.
Sound Test
Sound is our biggest enemy. Even a quiet bike is a disturbance to non-riders in the forest, and they are vocal with the overseeing governmental agencies. Once again, promoters are put on the spot, and other riders must face the consequences of your actions.
Our equipment is professional grade and calibrated prior to each event. On occasion we do use a consumer-grade sould level meter (SLM) for spot checking machines. We've tested over a thousand bikes using the same method, creating a baseline from which we work. Testing Procedures
Our goal in following strict procedures is not to turn people away. We do the tests the way we do so everyone gets a fair shake. It's about being consistent. As you read the procedures, you will see we give every advantage to the the testee and you will always get the benefit of the doubt. For example, the bike being tested is the only vehicle in the testing area that should be running. That way, other bikes do not add to the indicated sound level and give a false high reading.
Microphone placement is very important. Imagine a line drawn in space that starts at the tip of the exhaust and extends out at a 45° angle from the long axis of the bike and is level with the ground. We place the tip of the microphone of the SLM 20” away from the exhaust tip, and hold it perpendicular to that imaginary line. So the SLM is facing basically backwards relative to the bike, pointing away from it.
We test the sound level when the bike is at 3400 rpm, which is about half of the redline rpm for most 4-stroke singles. This is per AMA sound check guidelines, which recommends 3400 rpm as a good engine speed for most bikes. We have a device called a "sirometer" that can tell us when the engine is at that speed and all we have to do is put it in contact with the bike. We have had good results using the rear fender/taillight assembly or muffler as a contact point. We have verified the indicated rpm on the device with the rpms on bikes that have tachs and they are pretty darn close to each other. If your bike has a tach, we go by that number. Again, consistency is important.
A sirometer
Finally, the SLM we use helps us be consistent because it has a capture/hold button on it. All we have to do is watch the sirometer for the engine rpm and as it reaches 3400, we press the hold button on the SLM. The reading is saved until the button is released. We always round the number down to the nearest whole number. For example, if it reads 92.9 dBA, then it is recorded as 92 dBA.
Acceptable Limits
The DixieDualSport goal is 92 dBA. If you have an unmodified stock muffler in good condition and it is above that number by a reasonable margin (keep in mind that the sound level doubles every 6 decibels, so a little bigger number is a lot louder), we pass the bike. If the muffler is in sad shape, or if you have an aftermarket exhaust and are above the limit, then you have to go make some changes (remove discs or repack) and be retested in order to pass.
Converted off-road bikes are louder than D.O.T. bikes, since they do not have to meet the same requirements by the EPA. An unmolested DRZ400 will usually come in between 88 and 90 dBA. A stock KTM 450/525 EXC comes through about 94-96.
Many riders do not know how loud their bikes are. We understand this, and here's what we do at the sound check:
92 and below gets you a pat on the back.
92-94 get's you a lesson on paying attention to your pipe.
94-96 get's you a lesson on repacking, a lecture on the importance of a quiet bike and the impact that sound makes on non-motorized forest users and forest residents. No one likes a loud motorcycle.
Above 96 dBA: Get's your name on our "watch" list for any future events, in addition to a trip back to your truck to try to quiet it down. Repacking, removing disks, whatever. Do not come back to us with steel wool or a coke can stuffed in your pipe or an inner tube over the end. You're doing yourself and the motorcycling community a disservice.
One of the biggest fallacies perpetuated throughout the internet and elsewhere is that you need to "open up" the pipe. Louder does not equal more horsepower.
And while we don't like to be hardasses about it, we have turned people away who have had bikes above 96dBA, have been abusive to the sound crew, and generally have a terrible attitude that will ruin our sport for everyone. Practice Respect. Respect for Rules, Respect For The Sport As A Whole, And Respect For Others.
Did you ever hear someone complain about a quiet bike?
Rich Bumar
Environmental Engineer
Dixie Sound Master
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rich_in_orlando
DDS LifeTime Member
Registered: 08/08/06
Posts: 164
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| | 09/25/07 | Reply with quote | #2 |
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I just wanted to add to the above post that I am happy to test your bike for you if you are concerned about passing tech during an event. I live in Ocoee, FL and can test your bike at my home as long as we have made prior arrangements. Also, if you are going to be on a ride I am at such as a regular ol' Sunday ride in the Ocala, let me know and I can bring the SLM and test your bike. It takes only seconds to do. |
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