Ultimate Street Bob muffler mod?

[OrdinaryJoe]

Nice ! Now all you need is to spray the inside with bbq paint to make your mod invisible.

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[Gary7]

Originally Posted by OrdinaryJoe

Nice ! Now all you need is to spray the inside with bbq paint to make your mod invisible.

Yeah, the flash on the camera really brings out the rust spots on those baffles. They don't look that bad in person.

I actually did get a can of black BBQ paint when I decided to do this mod. But I decided I did not want to put all the prep time into these that it would take to get the baffles ready to take (and keep) paint, since I don't know how they are going to sound.

If I like the way they sound, and they are not too loud, I'll probably pick up another set of Street Bob take-offs down the road and "do them up right."

[Gary7]

I put these modified muffs on this morning and then took a 100 mile ride up through the mountains this afternoon. All I can say is...

WOW.

It's un-fricken-real how good these things sound. They are very LOUD, but not in an obnoxious way. I'd love to have someone ride my bike so I could hear what they sound like taking off and going by. But man at idle it's a BIG BASS THUNDER. And when you're under way and get on the throttle, think 50-caliber machine gun firing 2000 rounds a minute with a big standup base playing backup. Cruising down the Interstate at 60-70 they are just a distant rumble, but when you twist the throttle it's 50-caliber time again.

I'm glad I decided to put a single wrap of the glass packing back in. I'm sure that's what's cutting the annoying high frequencies and giving off such a nice deep, throaty rumble with none of that crapy metallic sound that typical Cycle Shack muffs have because they don't have any glass packing. And believe me when I say deep rumble, I really mean deep. I could actually feel it in my chest when I'd get on throttle and accelerate up through the gears.

These are definitely a keeper. Anyone with a Street Bob who is thinking of laying out some serious scratch for V&H, Rush, or Rinehart slip-ons should consider this mod, especially if you like the deep tone that Rush and Rinehart muffs produce. I think these sound every bit as good.

Here's what they look like on the bike:

[lunchmeat]

This work on a 09 custom? What about tunning?

[RED_5]

Hey nice work. In the future I would like to get a full system but until then I might have to try this. Can you recap the procedure again?

[Gary7]

Originally Posted by lunchmeat

This work on a 09 custom? What about tunning?

Yes, my bike is an 09 Custom, but the muffs are off an 09 Street Bob. I would not attempt this with the std muff off a Custom.

Bike runs fine. Pulls just as hard as it did with the Scremin' Eagle SP muffs. No backfiring on deceleration.

Originally Posted by RED_5

Hey nice work. In the future I would like to get a full system but until then I might have to try this. Can you recap the procedure again?

Drill out the rivets on the SB muffs. Mask the area first with duct tape to protect the chrome. Knock the old baffles out. The glass packing will still be in the muffler. You'll note that it's a double layer. Pull it out and cut off enough to make it a single layer, then put it back in.

At this point you can just put the new baffles in, but they will rattle if you don't do this next step:

The internal head pipe inside the muffler that the original baffle slips over is 1-5/8" OD to accept a 1-3/4" OD pipe, which has an ID of 1-5/8". The ID of the header end of the Cycle Shack baffles if 1-7/8" ID tapering to 1-3/4" ID. So I had to get a piece of straight 1-3/4" OD and fit it inside the header end of the baffle so the baffle would fit snugly over the internal header pipe inside the muffler. This prevents rattles.

Once you've fitted this "adapter" pipe, slide the baffle in being careful not to snag the glass packing. Use a rubber mallet to seat the baffle the correct depth, which is about 0.2" from the edge of the muffler.

Now you've got to drill the baffles for the mounting bolts. The Street Bob baffles are held in with three rivets, so there are three holes in the muffler can. I chose to only drill out two holes to mount the new baffles. I did not drill the middle hole. I forget the size, but use a drill bit that will just fit through the existing hole in the muffler body. Again, mask the area around the hole with duct tape so you don't damage the chrome.

Once you've drilled the holes, all that's left is to do is insert the mounting bolts (which are supplied with the new baffles) and tighten them good.

Install the muffs and enjoy the sound.

[Stanger]

Goog job! Interesting idea

[Black No.1]

Did you reinstall any of the glass packing? How's the performance/sound?

[Black No.1]

Disregard. I hadn't refreshed the page since this morning.

j

[Black No.1]

How loud?