Now THIS is TRICK! A solution, Part 1.

See Page 2 for the Installed Pics.

In keeping with "Loud Sucks", we will be testing various potential solutions ... We all know it's a MAJOR problem, our riding areas and tracks are being shut down at an alarming rate. ALL of us need to be aware and we ALL need to do what we can to pass the word that Quiet is Cool. The way things are going, soon you won't even be able to start that bad-ass bike of yours in your own garage.

With the cost of 4-stroke exhaust systems reaching $1,200 in some cases for an exotic dual setup that surely tops 100 dbs, we are currently looking into inserts/endcaps/quiet core add-ons for stock and aftermarket exhaust.

First up is a killer system from ProMoto Billet ... a dual kit for the '06 CRF250R. We received today the billet, cone style end caps with screen type, approved spark arrestor. TRICK! Billet goodness. In addition, we got the optional 96 and 94 db tips, that allow you to quickly change your sound levels ... one allen head screw is all it takes to remove and or change the tips. Sweet. (see the image below)

Next post I'll include a sound test of the stock dual pipe set-up using accepted standards (Rich is donating a tach), then detail the install and sound checks (SA only, 96, 94 and both with SA). The third installment will be the seat of the pants dyno.

Stay tuned and KEEP QUIET! :cool:

What the dyno shows and what happens on the track/trail are rarely the same, add in the cost to rent the time, a wheel/tire combo .. it's just not worth it, IMHO.

Cost on the dual pipe end cap with SA is 249.00 ...
Similar (looks the same) part for the 450F is 124.95
The tips are 79.95 per set (on the CRF250 - dual)
A 96 db version for the CRF450 is 46.95

Check their site for availability on other bikes....

The test bike;

About testing....

1) We'll use the standard "stationary sound test" (SAE J1287 - Motorcycle Industry Council and Society of Automive Engineers)

2) We'll use the supplement (1985-2005) Model Test RPM Data.. to determine testing RPM for anybike sound tested by DRN. Here's a link to the document: http://www.mic.org/members/membership/STMTABLE85-05.pdf

3) The sound meter used is a calibrated, Radio Shack Digital, part number 33-2055 ( Link Here

4) Procedure - SAE J1287 summary

Preparation

For convenience, attach a 20-inch string to the front of the sound level meter for the stationary sound test. Do not use a stick or wire for this purpose as the sound level reading may be affected. Allow the sound level meter to come to the same temperature as the surroundings. Set sound level meter to the slow dynamic response and the A-weighting network.
Test Site

No one should be within 10 feet (3 meters) of the vehicle other than the rider, the sound meter operator, an assistant to hold the front of the vehicle (if needed) and one other person directly behind the sound meter operator (if needed). The test area should be a flat, open surface free of large sound-reflecting surfaces within 16 feet (5 meters), such as parked vehicles, buildings, signs, and hillsides.

The surface should be free of loose soil, snow or grass higher than 6 inches (150 millimeters). The ambient sound level (including wind effects) at the site shall be at least 10 dB lower than the sound level of the vehicles tested. Always use a windscreen under windy conditions. The stationary test procedure should not be conducted if the wind speed is 20 mph (9m/s) or higher. If it is necessary to test in higher winds, position the vehicle so the wind direction is parallel to the normal direction of travel of the vehicle. Also, do not attempt sound level measurement when it is raining or snowing.

Measuring the Vehicle Sound

Make sure the engine is warmed up and the transmission is in neutral. Have the rider sit on the motorcycle with both feet on the ground, or on the footrests, so that the vehicle is vertical and stationary.

Hold the sound meter at a 45-degree angle to the exhaust centerline (the normal line of travel) Parallel to the ground 20 inches (0.5 meter) to the rear of the exhaust outlet at the same height as the exhaust outlet.


Determine the test RPM for the make, model, and year of vehicle
Set the vibrating reed tachometer to the test RPM, or attach an electric tachometer.

Have the rider or assistant hold the vibrating reed tachometer against any solid part of the vehicle, or have the rider or assistant read the meter of the electric tachometer.

Have the vehicle operator slowly increase the engine speed to the test RPM. Have the vehicle operator or assistant signal when the correct RPM is held.

Read the sound level meter when the correct RPM is held.

FYI: Here's sound data collected by the California State Parks Off-Highway Motor Vehicle Recreation Division.. lots of bikes covered and some surprising results.

Link: http://ohv.parks.ca.gov/default.asp?page_id=23038

Chili said:

You do realize it might get dirty

Click to expand...

But it won't stay that way :) Yeah, I'm a little stupid about keeping it clean, lol.
At the moment, its dirty AND bent ... thanks to the big man at Service Honda.

XRpredator said:

Little Big Man?

Click to expand...

No, normal size big man.

You broke several things on that one bike tho ...

Back on topic ....

Had some time to get a good look at the PMB stuff... impressive. One of the side benefits will be the end caps are about an inch shorter than stock, they'll be completely behind the side panels... need all the protection we can get for the dual pipes, that's got to be a good thing. Second side bene... they look WAY better than stock :) ... while there is a (marked) left and right side, only the inside diameter of the right side is smaller than the left (like stock), but the out side portion (the red part of the end cap) are the same size holes... someone put some thought into that. As I said, impressive.

There's just something about well made billet parts that make me smile :cool:

Kiwi...
if we can pull it off, I plan to do "track-side" tests as well ... if we can isolate our test bike anyway, but yeah your idea is good as well, as important as the standard sound tests are (usable as a baseline), we also want to know what he max sound levels are and how far the levels travel. I'm trying to work out my own "standard" now.

Pics: Installed
Def rates high on the bling-factor, provides a SA and sound solution. Need a SA to ride? Put it in. Need to go stealth? Put it on. Track out in the middle of nowhere and noise not an issue? Run just the end caps.
Sound test to follow.

Number Two: End caps with SA installed; note, the PMB Endcaps are shorter (1") than stock, tucking behind the side panels nicely.

Number 3:
Install time: 2 hours

Drill 6 rivets out on each can.
Heat the seam There's some hardcore sealent in there from the factory. (I used a torch)
Remove end caps
Bead of High-Temp Silicone
Insert PMB
Drill 12 new holes (3/8 bit)
Use existing metal "supports"
12 rivets (supplied)
Done.

Notable sound difference just with the SA ... I'll provide the numbers with SA, without, with Quiet tip (96 dB) and "silent" tip (94dB). Stock measured 98 db using the procedure in this thread, confirmed by Dirt Rider Mag in this month's issue (97.8).

Last one;

More Pics: 96 dB Tips istalled... 2 allen head screws, 2 minutes.

Number 2:

Number 3: