I agree with Hoist, and many who have tried them, the SPO's might be the best sounding performance mufflers that I've installed on my SEEG. The explanations given here and in other threads of how they sound have been pretty spot-on to my experience...
Compared to the Reinharts that I replaced, the SPOs have a more "muffled" note. They have a deeper or lower toned sound. It will take a while to get accustomed to the look - at first they are huge and hideous... Compared, you will lose a bit of the top end (Seat of Pants Dyno) having noticed that I must downshift more often when climbing a grade or passing then with the Reinharts.
In the end, although I love the performance and sound of the Reinharts, I think the sound of the SPOs is what I prefer on a tour bike. So I guess I am saying that I'm willing to give up a little on the top end to have a bit of quiet for the long haul.
But how much more quiet? I thought to conduct a non-scientific test...
Using a db meter, with samples taken at chest height behind the windshield and fairing, the SPOs reduced the sound output on average of 10 db throughout the RPM range from idle to 3500 RPM when compared to the Reinharts. The db range for the SPOs was 70 db @ idle to as much as 110 db @ 3,500, The Reinharts started at 80 db at idle and peaked at 120+ db at 3,500. wait for it... your results may vary
Other issues:
I think it was Ironhourse who scraped his SPO's on certain turns. I wonder if he is using the stock head pipes??? I've not scraped my SPOs and I have had them at some pretty extreme lean angles. Might be the V&H TDs I used help with clearance issues. The V&H TD kick up a bit on the right side and may be tucked up a bit more on the left. I'm not sure if this is it, but I have not encountered any scraping of the SPO and a riding buddy says he believes my floorboards come closer to touching than the SPOs...
All in all, it is personal tastes and riding style that determine what works best for each rider. I've tested my share of exhaust and the SPO's work for me... well for today
