The December issue of Dirt Rider includes a 96-Decibel pipe comparison story and the Hindle is tagged as Non-compliant.
Non-compliant. That means that a pipe failed our sound test. On a fair share of public lands in the US, it is illegal to ride with a loud muffler. Just look at the fine print at your local riding area, or even the rule book for your racing organization. They may not enforce it now, but it is coming soon. In this particular 96 db Pipe Comparison, the Hindle, after about 30-40 minutes of run time to break it in, blew an excessive 99.5 db reading on our WR450, prompting its non-compliant stamp and lack of a full test report.
The pipe Hindle sent for the CRF250X passed, so we rated it in the pages of the magazine, yet noted our concerns with its sound as well.
All of the other pipes in the test passed, showing that pipe manufacturers have the technology to make power gains, all with plenty of different power characteristics than stock, keeping you out of the grasp of the Man.
Why does Dirt Rider do all this sound testing and take it so serious? First, it is responsible. How'd you feel with your new Brand X pipe, out on your first ride only to be sited by a ranger? In California that can cost you a day of riding and even a hefty fine. Or at the race where they have a sound test and you get turned away. Hasn't happened to you yet? Well soon it might as the sound issue is the current "hot topic" affecting our sport.
It is very easy to get gains in power with an aftermarket exhaust. Most riders are comfortable bolting on a pipe. It is simple and quick. And pipes easily add a bling factor to your ride. But you should also be concerned with the increased noise output. Use our ratings as a guideline to what you can expect a pipe to ring in at. We use the same SAE J-1287 method that is identical to any properly conducted test.
And as much as we like the sound of a good running bike, it is music to the ears, it doesn't have to be front-row at Metalica loud for us to enjoy it. That way those who hate us will hardly even know we are there. The old saying may be "out of sight, out of mind", but I'm sure less sound will attract a lot less attention.
Some useful links about OHV sound