Skeptics Review of SBP Tuned Pipe

GoldenMotor.com

xlite

New Member
Jun 18, 2009
735
0
0
ny,ny
Well... I finally went for it. The famous tuned pipe kit. I promised I'd never spend more for a hop-up than for a new motor. But it was highly recommended by a couple individuals here whose opinions I respect and only $1 over my limit sooooo..... turned out to be well worth the investment.

The install took less than a half hour with a Zoom 67cc slant on one of my Magna Glacier Point bikes even encountering a couple small issues.

The first was holes on the flange were too small for standard HT exhaust studs. Only took a minute with a hand drill to fix that. Might suggest doing that a service to customers or at least mentioning in the manual. At that point I noticed a defect in the flange surface that might cause leakage (see pic). SBP promptly responded to email with suggestion to machine the surface (yeah right!) or send it back for replacement (yeah right!). I decided to simply plow ahead and see if and how bad it might leak.

After a few minutes of fitting and twisting it became apparent the stock mounting hanger was not going to allow use of my regular kickstand. The manual mentions switching to a different type kickstand. Not an option for me. So out with the kit hanger and in with some galvanized baling wire(see pic).

Positioning the pipe is a little tricky due to clearance issues between front tire, left and right pedals, and rear tire. It also initially wanted to direct exhaust onto the rear rim. A few minutes of twisting and re-aiming came up with a reasonable compromise. Cutting an inch or so off the copper tube solved front tire clearance. Bending the pipes original pocket bike mounting bracket out of the way helped with right pedal contact. It still hits occasionally so I'll probably cut it off completely at some point.

Next problem was the hose clamps are too small. They were both the same size and barely fit over the small end of the silicone tube and not even close to fitting over the fat part. Fortunately I had one of those Harbor Freight assortments and the biggest ones fit. Now we're ready to go!

It was immediately apparent more low end power was available. However the motor ran out of poop and made that "too lean" sound at WOT. And I noticed full choke don't stop the motor any more which is the only way I ever shut down. Needle clip down one notch fixed the choke. Replacing my "wide open filter" (see pic) with the stock air filter cover (see pic) took care of the WOT problem. I may investigate opening up the jet from it's current .028" and taking the stock filter off again later.

Once more with feeling! Even before getting to "dynamometer hill" the increase in low end torque was obvious. Even with the 36t sprocket ($12 BGF) it was now possible to get rolling w/o pedalling and took much less time to get up to speed. Evident beyond the realm of placebo effect. Prior to the install I did a test run up dyno-hill at the expected 23mph. Now it zipped up at 27-28mph. The GPS don't lie.

Noise was significantly louder than stock. Part of this may be due to leakage caused by the flange defect but I suspect SBP sells that lawn mower muffler option for a reason. After the test runs I put on the smaller silicone tubes but no real change in sound. Like mentioned by others it now has that "dirt bike" sound specially when throttling down. No room to stick a muffler on the end because of kickstand clearance but not as bad as a stock exhaust w/holes.

IMO only room for kit improvement might be bigger hose clamps and mentioning undersized flange holes or even drilling them out. Maybe remove the original pocket bike mount too. Easy for a machine shop. Maybe others don't have problems here.

I'm not sure how much of the power increase is due to the leak and how much due to the tuned pipe. In any case well worth the $78 in terms of engineering and materials. I bought the same exhaust w/o fititngs from another vendor last year for about half that but, after assessing effort needed to adapt to a HT, put it on the shelf. A wise move considering how easy it was to intall the SBP kit. Definitely a keeper.
 

Attachments

RedB66

Active Member
Dec 28, 2007
1,020
14
38
Sunshine State
Not positive but.... I think you should have two more pieces of silicone tubing around the connections on the copper piece. One on each joint... that (they) don't require clamps. Are your CDI wires resting on the pipe?
 
Last edited:

BarelyAWake

New Member
Jul 21, 2009
7,194
21
0
Maine
I just posted this elsewhere but I thought you may be interested in the low cost yet effective and easily adjustable rear mount I came up with, so I hope you don't mind if I go ahead and quote myself lol;

I just remounted my SBP tuned pipe, only supposed to be a test fit - it's worked so well I'm going to leave it :D


Yep, that's just two stainless hose clamps and two chunks of high pressure/high temp hose o_O Yet it's so solid and exactly where I want it, I think the only thing I'm gonna add is bits of inner tube between the clamps and the frame.


Heheh, yessir - more high temp hose makes a fine extension! Stops the exhaust from spewing nastiness on my kickstand and bag and actually helps take the "bang" out of the sound and deadens it a bit.

I don't think it looks that bad even with hose clamps all over the place... mebbe I'm just gettin' used to it lol
The length of the header (and that copper straight bit) allows for some tuning of the pipe, I've not messed around w/that other than trimming the copper one just to get it to fit - but I'm quite happy with the response it has now.

I had the same problem with the second hose clamp over the large end of the blue tubing, a shame really because they're quite nice clamps... I did manage to get it to fit with some soapy water and frustration, but I'll weld that section at some point anyway.

Much as they're handy, I've too many blasted hose clamps on my bike already :p


edit: did you remember to make the center hole in the gasket larger? It's quite a bit smaller than both the exhaust port and the manifold, a somewhat serious restriction of flow, I found I made the hole about 30% larger than stock... (oval instead of perfectly round)
 
Last edited:

Shadeslay

New Member
Feb 25, 2009
119
0
0
Arroyo Grande, Ca
On mine I found after a while leaving the springs to hold the top assembly had allowed it to vibrate to much and start leaking. To fix that I used plumbers tape to attach the header to the the frame. I also used rtv on the connections, the main one I found to leak is where there is no silicon coupler. The copper coupler that attaches to the part that mounts to the motor, that's where most of my sound was coming from. Once it's all sealed up the sound level goes way down and you can hear it from the rear of the exhaust instead of from the front.

Also you could try sweeping up the rear of your pipe, that should give you some clearance, so you can go over curbs with out dragging your pipe. The plumbers tape will work well for securing the rest of your pipe as well.

P.S. Barely I like the hose extension. I used a copper 45 on mine to aim it away from my bike. But that looks much cleaner, I may have to try that.
 

BarelyAWake

New Member
Jul 21, 2009
7,194
21
0
Maine
Yeah Shadeslay, I just stuck it on there to see how it would look and it happened to fit perfectly! So naturally I had to ride around w/it :D


xlite,
Hmm, due to Venice's duct tape comment I took another look... what is that doing for ya? o_O

BTW, ya might wanna flip the manifold plate around so the loop for the springs is underneath, making the springs wrap around the pipe. This provides a more uniform pressure and holds everything together better.

You defo wanna get both springs on there, they're all that are holding the pipe together. Those springs are so prone to breaking from vibration and heat combined with time that they are usually backed up with a safety-wire tether (something I've been too lazy to attend to lol).

Having a second one reduces the stress and provides a "second chance" should the other fail. I really don't wanna run over my exhaust system at any speed :p
 
Last edited:

Ghost0

New Member
Mar 7, 2008
763
1
0
Bellingham, WA
Thanks for the honest review. Sorry about the defective header. We can replace it for you, don't know what else we can do about that. We have not heard of the header not fitting the studs though. We will look into that. As far as the hose clamps they were not intended to go over the enlarged section of the pipe but on either side. I guess we should clarify that in the instructions. Again thanks for the feedback. We are constantly working to improve our products but without feedback we don't know what we need to do.
 

xlite

New Member
Jun 18, 2009
735
0
0
ny,ny
Not positive but.... I think you should have two more pieces of silicone tubing around the connections on the copper piece. One on each joint... that (they) don't require clamps. Are your CDI wires resting on the pipe?
As mentioned in my post the small silicone tubes were installed after test runs. Made no immediate difference.

Not obvious from the photo but the wires are actually 2" or so away from the pipe which is in same position as the stock exhaust was. I put thousands of miles a year on these bikes... believe you me... problems like that got ironed out some time ago.
 
Last edited:

xlite

New Member
Jun 18, 2009
735
0
0
ny,ny
xlite,
Hmm, due to Venice's duct tape comment I took another look... what is that doing for ya? o_O
Oh..ok... the jig is up. It's a chain guard. I need access to service the chain and swap engines so often so out with that stock black metal guard, in with the duct tape. Keeps the lower 6" of my jeans from jamming in the sprocket and locking rear wheel. Even a new pair from Walmart adds up.

BTW, ya might wanna flip the manifold plate around so the loop for the springs is underneath, making the springs wrap around the pipe. This provides a more uniform pressure and holds everything together better.

You defo wanna get both springs on there, they're all that are holding the pipe together. Those springs are so prone to breaking from vibration and heat combined with time that they are usually backed up with a safety-wire tether (something I've been too lazy to attend to lol).

Having a second one reduces the stress and provides a "second chance" should the other fail. I really don't wanna run over my exhaust system at any speed :p
Spring on the bottom results in contact with the downtube. I tried putting two springs on but, again, downtube contact and hooks on the ends didn't seem as secure.

That safety wire idea (as you can see I'm very fond of wire) is definitely on my list.
 

BarelyAWake

New Member
Jul 21, 2009
7,194
21
0
Maine
That's why I don't wear bell-bottoms you hippy :D


It's hard to see in this pic, but I just used a piece of old rim liner (or inner tube w/e) between the spring and the Dtube to reduce chafe;



Ya prolly know this, but run yer safety wire through the middle of the spring to both loops. This way should it just be a hook that lets go (usually what happens) - you still have the spring and can rebend a hook ;)

Ofc... I've still not followed my own advice meh - watch as I loose a spring on my ride to work today lol

edit: a very neat and tidy solution with some shrink tubing (and far more than just mere safety wire no less lol);


more good info on exhaust systems using spring retainers;
Exhaust springs, Rotax exhaust springs, exhaust spring installation tools and tips.
 
Last edited:

xlite

New Member
Jun 18, 2009
735
0
0
ny,ny
Also you could try sweeping up the rear of your pipe, that should give you some clearance, so you can go over curbs with out dragging your pipe.
wow,
that thing is lowwww....
Actually appears that way due to camera angle but it's not. Pedals go much lower than the pipe.

I probably spent 25 min twisting and adjusting for best fit and clearance but only 5 min assembling and tightening so hard to improve that position. AFAIK I'm the only person here to install one of these and keep the stock kickstand?
 

BarelyAWake

New Member
Jul 21, 2009
7,194
21
0
Maine
Hmm, actually I changed my kickstand before the SBP expansion chamber - I'm not 100% sure but I think my old stock kickstand would still fit... mebbe

I changed the kickstand to a rear mounted one because I tend to have a LOT in my packs, I commute to work and go on "long" trips so they're usually packed with all sortsa crap - not least of which is the netbook laptop I use for tunes etc. at work (the value of that modded lappy exceeds my bike lol).

The stock kickstand on a new Schwinn is a total POS, even unloaded I could stand there and watch it bend. A heavy duty kickstand mounted near the center of weight is defo the way to go. I'll be getting a centerstand at some point if I can figure out how to make it fit ;)

BTW - insofar as SBP exhaust system mounting techniques, apparently mine can withstand a roughly 30mph cartwheel - not bad for about $5;
http://motorbicycling.com/f3/smash-never-let-anyone-ride-yer-11338.html
 

xlite

New Member
Jun 18, 2009
735
0
0
ny,ny
I'm not 100% sure but I think my old stock kickstand would still fit...
If your kickstand was a regular type like mine then, looking at your photo, that is not even a remote possiblilty.


BTW I just added wire to the spring and feel much better about the setup. I had big problems with those on the Rotax for my MX and the one on my new pipe made me nervous. NO MORE! Thanks for the reminder.
 

xlite

New Member
Jun 18, 2009
735
0
0
ny,ny
Sorry about the defective header. We can replace it for you, don't know what else we can do about that.
I was kinda hoping you were going to tell me "Oh.. they're all like that. No problemo." :)

Returning for a replacement was not an option as I was anxious to get going. The leak was REALLY bad with the aluminum gasket. Not so much when I went back to the stock gasket. What's up with copper/aluminum gaskets? I don't see the point. Note that the cyclinder is make of aluminum.

We have not heard of the header not fitting the studs though. We will look into that.
The studs were a few thou bigger. Just enough to prevent fitting. You can see in my pic the flange does not resemble the one in your manual. And there were only 2 copper tubes, not 3. Apparently you have changed the design somewhat.

As far as the hose clamps they were not intended to go over the enlarged section of the pipe but on either side. I guess we should clarify that in the instructions.
Confused. I thought it was assembled exactly as shown in your manual. The smaller pipe fits inside the bigger expansion chamber. Silicone tubing over that junction holds them together. There will be a small part and a fat part to the silicone. The hose clamps barely fit the small end and not even close to fitting the fatter part. A couple sizes up would work for both.
 

Ghost0

New Member
Mar 7, 2008
763
1
0
Bellingham, WA
The use of nonferrous gaskets is to combat leaks due to heat cycling. The theory is that if the metals have the same coefficient of thermal expansion they will expand and contract at the same rate which should then never create a leak. By using the stock gasket you improved your seal because it is soft and will mask the defective header but will leak over time due to the dissimilar material heat cycling.

We test fit about 10 of the headers and they all fit, I think you just got a bad one. Again we will be glad to replace it for you. We have made improvements to the header eliminating one of the copper pieces and having it incorporated into the header. This eliminates one point of potential leak.

You did install the clamps per the manual but we are constantly improving our products and in doing so created a slip joint and have not covered the correct clamp installation for the newest pipe, there are still some of the earlier ones out there. The clamp should go on either side of the slip joint on the smaller diameter tube section. Then the clamps will fit. I have attached a photo of what will appear in the manual
 

Attachments

xlite

New Member
Jun 18, 2009
735
0
0
ny,ny
The use of nonferrous gaskets is to combat leaks due to heat cycling. The theory is that if the metals have the same coefficient of thermal expansion they will expand and contract at the same rate which should then never create a leak. By using the stock gasket you improved your seal because it is soft and will mask the defective header but will leak over time due to the dissimilar material heat cycling.

We test fit about 10 of the headers and they all fit, I think you just got a bad one. Again we will be glad to replace it for you. We have made improvements to the header eliminating one of the copper pieces and having it incorporated into the header. This eliminates one point of potential leak.

You did install the clamps per the manual but we are constantly improving our products and in doing so created a slip joint and have not covered the correct clamp installation for the newest pipe, there are still some of the earlier ones out there. The clamp should go on either side of the slip joint on the smaller diameter tube section. Then the clamps will fit. I have attached a photo of what will appear in the manual
As an engineer and mfg myself I understand how these things "slip" through the "cracks". :) Still not sure what slip joint changes were made. The photos look similar. It still appears to me clamps are too small regardless of version. Even on the small end mine barely fit. For example with clamp on but not tightened the pipe can not be inserted. And others in this thread have mentioned the same issue. Anyway, a couple from the HF assortment solved the problem.

Interesting about the thermal expansion theory. Never had leaks with stock gaskets but they are so brittle great care must be taken when reusing them. I like Mr Gasket 5961 Ultra Seal material (Amazon) best. Easy to cut, not brittle, cheap, and lasts forever.

All-in-all I'm really pleased with the ease of install and power increase for the kit.