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Simple Sportster Muffler Mounting - More Details

Posted: Mon Mar 22, 2010 2:02 am
by rdurost
OK, I can't get the Gallery working for now, so here's the scoop.

The pre-bent pipe sections used to join the headers and mufflers are 20 degree 1.75" ID/OD pieces, not even trimmed for length. They're not that easy to find in stock, but a couple auto parts stores were able to order them for me. They were fairly cheap, as I recall. Unfortunately, the inside of one of the bends is corrugated, while the other (which I prefer) is smooth. You'll see what I mean. Eventually I'll replace the corrugated one.

If I had any brains at all, I'd have written down the part number before tearing off the stickers, but oh well. It's been a while, but I believe I got them from NAPA.

I used Harley band clamps, which are unbelievably rugged, don't deform the pipes, and cost less than $8 each.

The hangers are 3/4" plated iron strapping cut to length and drilled. The lengths are slightly different side to side because the brackets on the mufflers are different. A key assembly tip is to slip everything together and get the heights and placement correct using whatever lengths of strapping are necessary, then slowly tighten the band clamps while keeping everything in alignment. Once it's all the way you want it, tighten the clamps very snugly. The clamps provide most of the rigidity in the system. I had to rotate the rear clamp on the left side so the bolt was at the top. Otherwise the centerstand hits the clamp.

The clamps the hangers hang from are the kind of thing that is used to attach a heater hose (for example) to a firewall. They are lined with rubber, which serves nicely in this case to keep the clamps from slipping on the frame, and it also keeps the clamp from marring the paint on the frame. I got them at Ace Hardware from the sort of drawers you get individual bolts from. They're nominally 1" in diameter, but they will wrap the slightly thicker frame tubing just fine. I used 1/4" bolts with Nylock nuts to keep the joints tight.

I cut a two pair of slots in the big end of the bends, lengthened the existing slot in the muffler and added a second pair of cuts at 90 degrees from them. This allows the clamps to shrink the diameter of the pipes without deforming them.

I had to dimple the inside of the left muffler about 1/4" in a couple places to keep it from rattling against the swingarm and the caliper bracket bolt when the muffler is placed at the same distance from the centerline of the bike as the right side, which has many fewer obstacles. The dimple is not deep enough to cause any deformation of the inner core of the muffler, and no such mod was required on the right side. They are essentially invisible on the bike.

Before:

Image

After (So Far):

Image

Closer:

Image

Rear View:

Image

Left side:

Image

Closeup of simple hanger:

Image

Richard

Re: Simple Sportster Muffler Mounting - More Details

Posted: Mon Mar 22, 2010 2:20 am
by rdurost
Can anybody tell me why the first two images won't load? The URLs are valid, and the syntax looks identical.

Yes - Changed the (s to an i) at the beginning and removed the (? content=view) before the (before.jpg) ... working now

If you right-click the word "image" for either of those and pick View they will load on PhotoBucket.

Richard

Re: Simple Sportster Muffler Mounting - More Details

Posted: Mon Mar 22, 2010 10:38 am
by Roady
I like that angle. And a nice, simple solution.

But you could clean them up quite a bit by rotating those clamps to the inside.

Image

Re: Simple Sportster Muffler Mounting - More Details

Posted: Mon Mar 22, 2010 11:28 am
by Rat
rdurost wrote:Can anybody tell me why the first two images won't load? The URLs are valid, and the syntax looks identical.

Yes - Changed the (s to an i) at the beginning and removed the (? content=view) before the (before.jpg) ... working now

If you right-click the word "image" for either of those and pick View they will load on PhotoBucket.

Richard



Check your PMs, I fixed your album up.

Gord :-D

Re: Simple Sportster Muffler Mounting - More Details

Posted: Mon Mar 22, 2010 1:46 pm
by rdurost
Roady wrote:I like that angle. And a nice, simple solution.

But you could clean them up quite a bit by rotating those clamps to the inside.


True enough, but that would sacrifice some function (easy access to clamp nuts) for form. My guiding principle is "form follows function." I want to see how far I can take that.

Richard

Re: Simple Sportster Muffler Mounting - More Details

Posted: Tue Mar 23, 2010 5:15 pm
by rdurost
Went to NAPA today and got the numbers for the elbow bends. These are all 20 degree, size is ID/OD, each side of the bend is 6" long.

1 1/2" = 41813
1 3/4" = 41814
1 7/8" = 41815
2" = 41816
2 1/4" = 41817
2 1/2" = 41818

Here's a .JPG of the page:

Image

And here's a .PDF:

http://www.mediafire.com/?2t0ncgeqrti

Richard

Re: Simple Sportster Muffler Mounting - More Details

Posted: Tue Mar 23, 2010 9:46 pm
by Roady
This has evolved into a very nice candidate for ShopTalk.

Tons of good info there.

Re: Simple Sportster Muffler Mounting - More Details

Posted: Tue Mar 23, 2010 11:23 pm
by rdurost
Roady wrote:This has evolved into a very nice candidate for ShopTalk.

Tons of good info there.


Thanks, I appreciate that!

Richard

Re: Simple Sportster Muffler Mounting - More Details

Posted: Thu Nov 15, 2012 10:21 pm
by reggiedude
I have mounted a new set of shorty pipes on my 77 GL. What do I have to do to adjust carburation to keep the pipes from turning blue. Any help? :orange

Re: Simple Sportster Muffler Mounting - More Details

Posted: Fri Nov 16, 2012 9:28 am
by Motowalt
The Goldwing engine is very forgiving with all sorts of exhaust mods...you shouldn't needed to rejet

Re: Simple Sportster Muffler Mounting - More Details

Posted: Fri Nov 16, 2012 7:12 pm
by Missourimike
reggiedude wrote:I have mounted a new set of shorty pipes on my 77 GL. What do I have to do to adjust carburation to keep the pipes from turning blue. Any help? :orange

Chrome that gets too hot, turns blue. Usually caused by a motor "out of tune", running too lean on the fuel. It's not the mufflers that are causing the problem. Wings don't like too much air getting into the cylinders, so use as close to an OEM filter as you can find. I've never had any problems with K&N, if that's your choice.

Re: Simple Sportster Muffler Mounting - More Details

Posted: Sat Nov 17, 2012 6:25 pm
by reggiedude
Thanks guys,

Can I tell if the bike is running too lean by how many RPMs it idles at? Right now it is idling at nearly 950 RPM, and I believe I read it should be around 650.

Re: Simple Sportster Muffler Mounting - More Details

Posted: Sat Nov 17, 2012 6:42 pm
by robin1731
950 is much better, 650 is too low. I usually go by what the bike likes. The tachs can be off sometimes. Better to listen and see when the engine is "happy".

Re: Simple Sportster Muffler Mounting - More Details

Posted: Sat Nov 24, 2012 2:10 pm
by wilf
As for adapters for the mufflers on my 1100 I scored a set of sportster mufflers complete with the header pipes from the heads to the mufflers . The HD pips are very good quality and chrome with lots of bends in them. You can cut a section out that has the right bend and have a good looking adapter pipe that is mandrel bent. And it welds way better than the cheap auto store pipe
Wilf

Re: Simple Sportster Muffler Mounting - More Details

Posted: Sat Nov 24, 2012 6:10 pm
by reggiedude
Thanks guys for all the tips. The shorty pipes fit exactly even though I don't know the brand. I ordered them out of a catalogue at Cycle Sales in Youngstown Ohio and they really are an awesome looking addition to these bikes. They are nice and loud, yet still have enough baffle in them for back pressure.

77 Naked Wing

Post edit - PM sent - Brant