Hindle Sound Level Comparison

Spyglass · May 19, 2024

In a previous post, I asked if anyone had gone from a Hindle Supersport to Stealth and what they thought of the change.

As there were no comments, I'm posting my experience here.

I chose the SAE J2825 Standard(ish) as there are a few jurisdictions that use this method, and it's easy to set up.

I used the NIOSH Sound Level Meter app since it was free, although it did not recognize my external microphone, so I was stuck with the limitations of the internal mic on an iPhone 13.

I compared three different choices: 1. Hindle Supersport Titanium, 2. Hindle Stealth Brush Stainless, and 3. Hindle Stealth Brush Stainless with Noise Reducer Inserts.

Both are 14" mufflers with 2.25" opening.

SAE J2825 calls for 5000rpm, but since I spend most of the time on the highway at 3500-4000, I went with that instead.

1. Hindle Supersport Titanium - 91.3dB at idle & max level 107.4dB
2. Hindle Stealth Brush Stainless - 89.0dB at idle & max level 106.2dB
3. Hindle Stealth Brush Stainless with Noise Reducer Inserts - 86.7dB at idle & max level 103.6dB

Standing next to the bike, I could not hear the difference between the Supersports and Stealth.

With the inserts, it was quite noticeable, although they sounded a bit tinny at idle at first. I may have to tap the inserts a bit better to ensure there is no play. There was still a health rasp when revving the engine. I have not had them out on the highway yet.

Here is the insert. You tap them in until reaching the end cap. The muffler core is tapered (unlike the Supersport), which retains the insert.

Side-by-side, there is a noticeable difference in the finish, plus we can no longer get the carbon tip, although I could drill the rivets and reuse them.

On the bike, the difference is more subtle. The light is not from the same time of day, but you can see the difference in finish. I think the brushed stainless now better matches the other brushed metal on the bike (last photo).

20Vmax20 · May 19, 2024

Very nice write up, I have been debating about changing to hindle exhaust from stock. My issue is that I love how quiet the stock setup is because I can get by with more fun without drawing as much attention. My stock exhaust, with or without the muffler bodies, is about 75db at idle and 89db at 5k measured at 10’ behind the bike. Thanks for the info though, I may have to bite the bullet and go for it.