So here are my observations

Part number :- SPZVHBR

CONTENTS :  

2 Hard Kore Quiet Baffles, 

1 Allen Key.

1. Remove the heat shield and original baffle with allen key provided.

2. Drill 5/16” hole in original baffle 7/16" from the end, close to the original hole in the original baffle.**

3. Insert Smartpartz Hard Kore Quiet Baffle into original baffle so that the Hard Kore Baffle is hard up against the end of the original baffle and the Smartpartz Hard Kore Baffle threaded tab is centered in the hole you drilled.

4. Reinsert original baffle with Hard Kore Baffle into exhaust pipe. Align hole. Reinsert allen screw from original baffle through the exhaust pipe, through the hole you drilled and into the Smartpartz Hard Kore Quiet Baffle, and tighten.

5. Reinstall the heatshield.

Impossible to rotate at all because of the curvature in both the pipe and the baffle. The baffles are very very snug in the pipe.

Alternative 1 Install) Remove the threaded tab from the original baffle with a dremel tool or sharp chisel (this tab will normally knock off pretty easily) - see pic below. Then you can use the hole from the original baffle to attach our baffle. Should you decide that you wanted to remove our baffles, you would just need to get a ¼ 20 nut from any hardware store and secure the original baffle with the original screw and the nut.

My issue:

The baffles from V&H no longer have an easily removed tab ( at least since 2016), they have an additional plate welded to the inside of the baffle that is threaded to give the screw some meat to lock in to. You would need to butcher the baffle to get the so called tab out. Because the tab is quite thick you need to remove all of it, otherwise the Smartpartz baffle cannot be centrally located, the thickness of the tab when pressed against the Smartpartz baffle mounting causes it to be off centre and it looks crap and the exhaust gases blow out past the baffle.

Alternative 2 Install) Remove heatshield and drill hole through the inner exhaust and the original baffle next to the threaded tab in the original baffle and secure our baffle. Once heat shield is replaced you will not see the screw.

So now I have an unused hole in my exhaust......

I did the following. Left the original V&H baffle mounted the way it was and drilled the second hole about 30 degrees away from the original hole towards the bottom of the pipe, so that the hole is vertically in line with the ground and completely covered by the heat shield, but the heat shield clearance around the pipe is such that you can only use a very low profile screw (read here 1/4 button head) same as the stock V&H one, to secure the Smartpartz baffle, or the heat shield will not go back on at all, and finding a couple of those screws has been a bloody nightmare!! I have had to order a pack of 12, for US$5.99 from J P Cycles, with a shipping cost of US$50.00!! WTF! How easy would it be to include a couple of extra screws in the package?

Other than that, it is actually very difficult to get the Smartpartz baffles centrally located within the V&H baffle because of the way the Smartpartz baffle is mounted. Round mounting in a round pipe and the Smartpartz mounting is such that when you tighten the screw it pulls the Smartpartz baffle off center.

Anyhow, I just wanted to share my observations with you guys, in case anyone is considering going down that road. 

The Smartpartz baffles do exactly what they advertised, and have reduced the DB of the pipes and I must say I like the rumble I get and the removal of the tinny hollow sound I got with only the stock V&H baffles I had in. My bike feels like it has more torque in the mid-range. You also cannot see the Smartpartz baffles unless you get down on your knees and look up the heat shields.  I’ll measure the actual DB and the difference when I get a chance to borrow a reasonable meter, and let you know what the sound levels are when measured using the noise measurement specifications a bunch of you guys kindly posted and commented on in other threads. I am also waiting for a new map for my ECU from V&H support because I’m using a lot more fuel than i did before!!