Akrapovic exhaust swap (pics!)

[aaron]

Like my windscreen reshaping project, this one has been a long time coming. I had considered getting a pipe for some time, but I don't modify factory stuff lightly. If I modify, it has to meet the "could have been a factory option" standard in appearance and performance. I had originally settled on the Two Brothers black series titanium, but they aren't available any longer. There are few other options, and I justified this Akrapovic setup because it has a titanium canister, and I was able to get it through Amazon with redeemed credit card points.

I was a little concerned because in general, I don't care for the look of carbon fiber, which is what makes the end cap on this unit. When I opened the box, however, I was blown away. The muffler is exceptional in quality (design, feel, material, craftsmanship) and, thus, appearance. The carbon fiber is an accent to the titanium here, which is its appropriate role. The stainless steel header was also top shelf. Shape, appearance, and the welding work were all very impressive and satisfying.

The mounting brackets, however, were a disappointment. The steel (not stainless) was good, sturdy quality, but unfinished. It was filmy in appearance, like how I imagine the parent stock looked. The mounting bolts were similarly industrial in appearance, like you might find in the drawers at your hardware store. Given the extreme contrast between the pipe/canister and the brackets, my recommendation to Akrapovic would be to market the brackets as unfinished (especially since rust may be an issue).

So underneath the bed it all went while I considered my options. With an eye on eventually powder coating it, I decided to spray paint it first to make sure the color was right (flat black like the other accents, or aluminum to make it look like a piece of the chassis.) I decided on black, but months passed before I realized I don't have the facilities or climate to get the paint on. (The farthest I got was hand sanding the bracket pieces). I eventually just threw in the towel and got the bracketry and bolt heads powdercoated flat black.

The results are fantastic. The color choice was right. The bracket blends in as an accent, it mirrors the O2 sensor cover, and the lines the color creates are perfect. It also emulates the design of the stock muffler mounting plate, and I am satisfied that it looks like it could have been a factory option.

The new system performs very well. It has a removable silencer in the end cap, but I've left it in. The sound at startup and idle is throatier than stock, but somehow subtle. There is vibration now (a sort of rumble) through the seat in the lower rev range, which quickly mellows as revs increase. At high revs/speed (perhaps because of wind noise), differences between aftermarket and stock become unnoticeable.

A Hand of God power increase would have been nice, but this is a 153cc bike that is already factory engineered to its limit. If there is an HP increase, I will find it at the rev limiter, which is what I expected, and that I have not yet had the chance to chase. What IS noticeable, however, is the weight loss. The Akrapovic setup is five pounds lighter than stock (14 versus 19), and you feel it. Losing 5 pounds off the side of the bike yields better, more assertive flickability. The SH is a regional commuter bike, and the best it can hope to be is a "GT" in that regard, but it now feels like it dropped a weight class.

I'll report back as I break the pipe in. The stainless header already faded to yellowish on my first outing. Next stop, purple!

[TommyXP]

Great read....Thanks for taking the Time to share.
If I ever fall into 2 pennies to rub together; this will be on the top of my list.
Again....Thanks for doing your/my homework.

[Mikey]

I replaced my exhaust with the same but also replaced the vario weights with lighter weights. There should be an old thread if you type the word Akrapovic in the search engine. Very quick off the line. I think it was semi responsible for my first accident last year from when the rear tire broke loose leaving a stop sign and the rear end fishtailed. I had the throttle wide open like always but must have met some slippery liquid laid down at the stop sign. Was on the ground within less the 10 feet. Very embarrassing but who would think you would be pulling burnouts with this size engine!

[Mikey]

Found it. Akrapovic exhaust and Dr. Pulley 10 gram sliders = more take off speed. Also paid $275.00 for mine on Ebay since the packaging was damaged. That's the only reason I purchased them being a somewhat frugal guy!

[313Matt]

Thanks for the writeup - looks great!

[aaron]

More observations after taking the bike out for a second time (first time crossing the Bay Bridge for work).

Before the swap, the kickstand would make a clank when taking the bike off the stand, and only when taking the bike off the stand. Now there is a clanking over rough pavement, as well. I've identified the culprit. The kickstand bumper is borrowed from the stock muffler unit, to the bottom of the Akrapovic mounting bracket. However, there is apparently less clearance now between the spot where the kickstand and the swingarm are closest when the kickstand is up. They collide together now when the kickstand is jolted over bumps (and I don't mean potholes and the like). The fix will either be a bigger or less flexible kickstand bumper (somehow), or I'll have to wrap a suitable piece of rubber around the kickstand where it collides with the swingarm. (The spot on the kickstand, specifically, is right near where the retracting spring attaches to it.) If you appreciate how solid the build of the Sh150i is like I do (like carved from stone), you will be annoyed, again (after the problem of being unfinished), that the Akrapovic bracket is a weak link.

Good news: power is definitely up. Around town at lower RPMs it's not quite noticeable. At speed, however, it is cranked to 11. Heading west, against the wind, up the Bay Bridge incline, it was pulling toward 70mph where it ordinarily would have run out of steam around 60 or so in those conditions. I've never shied away from freeway riding on my Sh, but now it will frolic a bit more than just make do.

[TommyXP]

....."frolic".....!!!
My Lungta (Wind Horse) loves to frolic too and the more frolicking the better.....

[Mikey]

With the combination of the new exhaust and the changing of the sliders, I seemed to have increased my takeoff speed with a loss to the top end speed. But the Akrapovic looks great and sounds great.

[aaron]

With the combination of the new exhaust and the changing of the sliders, I seemed to have increased my takeoff speed with a loss to the top end speed. But the Akrapovic looks great and sounds great.

It does. I will forgive the bracket because the pipe and canister are really fantastic. The bike has a growly presence now, and it just drifts toward 70mph on its own. I put in 12g sliders shortly before installing the Akrapovic. The factory rollers were 12.5, and I favor power at speed over power off the line. Do NOT want to burn out!

[aaron]

More observations after settling into life with the Akrapovic:

1) I really have to deal with the kickstand clanking into the right side swingarm over bumps. The tendency to clank over the slightest jolt is a dealbreaker for me. I think the right size coolant hose cut-to-fit around the contacting portion of the kickstand will solve the problem. Has to be durable enough for me to put it on once and not require constant tending or frequent replacement.

2) I noticed right away that the bike needs less throttle now to hold a given speed. It's actually surprisingly little throttle when maintaining speed around town or within cruising speed. I'm barely above the detente position when cruising anywhere below 50mph or so. Data corroboration is in the mpg gain. Prior to the swap, I was typically tracking around 74-75mpg. Today's first full Akrapovic tankup showed 87.6mpg. That's a 17% gain. I am admittedly a "finesse" rider, so your mpg gain may be different, negligible, or worse.

3) I have not yet had an open enough road to chase the rev limiter. However, two days ago I took a stab at a high speed. I blew straight through 70mph into thickening traffic and backed off at 72mph. My bike in its current tune will certainly put Dr. Pulley's claim of increased top speed to the test. More to come...