General Thoughts - Expansion Chambers

[ADDICTED BICYCLES]

Hello fellow Motorbicyclists! In this thread, I'd like to hear your opinions on expansion chambers, some tips or tricks, or useful things to know about expansion chambers.

I am ordering some parts next week when I get paid, and an expansion chamber is catching my fancy, however I don't want to waste my money, so I request your thoughts on the matter.

Thank you!

 

[BarelyAWake]

The general consensus is ya need a certain amount of head pipe to "tune" the powerband increase where ya wants it - I've heard anywhere from 8-12" whereas that 'un doesn't have any at all *shrug* However - any expansion chamber is a heck of a lot better than the stock mufflers these things come with... so it's a matter of expectations vs budget and/or fabrication skills.

I will say with certainty that that pipe is freakin' LOUD My friend's kid just got one for his ride, as he's down with the noize - the lack of a silencer doesn't bother him... I would heartily recommend some sort of secondary mount as well - that's a lotta weight jus' danglin' off the exhaust studs It was a crazy simple bolt-on mod to put that pipe on tho... so that's a plus.

Given a choice - I'd still roll with the SBP one, it does cost more and is a bit more labor intensive to properly mount it, but havin' tinkered with both now it seems the SBP one provides more of a distinct power response, the assembly can be tuned & tailored (fitted) to the bike, and ofc - it doesn't irate the popo quite as much... mebbe o.o

 

[bluenosegoat]

I recently installed a Sbp pipe on my bike and I am very pleased with it. I still havent messed with shortening the header pipe as I have the shift kit also and like a lot of torque- I pull a trailer with either my daughter or groceries. The torque also allows me to cruise in a higher gear at low rpm and with the extra silencer it is very quiet. The power increase was a big shock! Made a huge difference and for me worth every penny.

 

[ADDICTED BICYCLES]

See, that "shock" factor in increased speed is something that really has my attention. I noticed that SBP chambers come with a silencer. How well does that silencer work? Will I still be louder with a chamber and silencer than I am now? I've never even seen one of these chambers in action, so I'm clueless. Bluenosegoat, the kit comes with EVERYthing you need? Like the gasket and what not? I'd imagine it would, but I'll need to order a gasket if not.

Thanks for all your input guys!

 

[bluenosegoat]

The kit comes with everything you'll need including a nice quality gasket. I purchased the extra silencer (I think it was 5 bucks, figured I'm paying for shipping get it all). I never ran it without the extra silencer but if you look at the pic of it in my previous post you'll see the included "muffler" and the extra silencer behind it. Side by side with my other bikes I would not say its any louder at all. I actually think its a little quieter. Definately sounds better and now my bike has zero four stroking and good power through all throttle posistions. Mounting is fairly easy. On my bike the clearance's are very tight for the pipe between missing the pedal crank and tire. I think sometimes it touches my tire but at that point down stream it is not very hot. I have almost 200 miles with the pipe now and wish I had them for all my bikes! If you have any questions at all Pablo and Jim at Sick Bike Parts are fantastic! They have the best customer service I have dealt with. Super fast to respond and more than willing to help you. Very good guys! You get what you pay for most of the time and with sbp you get that and a lot more. Hmm I sound like a comercial! Anyway I'm sure you'll love it. I know i do.
I havent tried any of the other pipes out there but after having the shift kit and knowing the quality these guys put out figured I couldnt go wrong. I am going to experiment with a pit bike pipe as I'll be welding in extensions for a cruiser I built so I dont want to mess up a more expensive pipe. I am so hooked on these bikes!

 

[Retmachinist]

I don't know how handy you are as far as being able to adapt one to fit your bike, but Pocketbikes.com has expansion chambers on sale right now for $21.95.
They are like the one on the bike below. You would need to cut the two ends off, and weld on the ends from your kit exhaust. They work great and are really quiet.

John

 

[bluenosegoat]

I don't know how handy you are as far as being able to adapt one to fit your bike, but Pocketbikes.com has expansion chambers on sale right now for $21.95.
They are like the one on the bike below. You would need to cut the two ends off, and weld on the ends from your kit exhaust. They work great and are really quiet.

John

Do you have a link to that site? I am getting the net runaround! Did find a cheap used one on ebay though.

 

[camlifter]

tuning the pipe on these motors dosen't really make a huge differance until you get the pipe so big that it looks like crap. we've found that you can use a shorter head pipe and longer stinger to make the pipe look good fitting it to the bike and still get a nice boost in performance. sure you can go for the all out tuned pipe and gain maybe a .1 more hp, but they look so ratty i'd rather go for good looks. we'll be posting pics of some pipes were putting on our bikes soon. the only problem is that to make a pipe look great you need the bike it's going on to fit it properly, to much varitation in the way people mount there motors and the bikes they use to really make a uneiversal pipe. you end up with pipes with hose clamps and sections of hose, they may work good but i think the look is too ratty.

 

[bluenosegoat]

I do have to agree on the hose clamps and such. Thats why I'm going to weld in one for my cruiser. The blue silicone on the sbp pipe matches my bike color at least! I dont want to weld it just in case I decide to relocate it. I dont want hose clamps and things on my cruiser. I even welded on cable holders to the frame to keep it clean- no zip ties on this one.

 

[Retmachinist]

Do you have a link to that site? I am getting the net runaround! Did find a cheap used one on ebay though.

Just Google pocketbikeparts.com Then scroll down the left side till you get to stock exhaust. Click on that and you will see several pipes. The one I use is the one that is on sale right now for $21.95. You can't beat it for the price. You can either use the muffler that comes on it, or cut it off and use the kit muffler if you want it to be nice and quiet!

John

 

[diceman2004]

RATTY ? look at retmachinists pick , that doesn,t look ratty to me

 

[BarelyAWake]

So many ppl forget that "beauty" is in the eye of the beholder - I for one greatly appreciate the look of a properly utilized performance part, knowing that it serves a distinct purpose.

It's the bits added on fer "style" alone I tend to find... odd-lookin lol

 

[RedB66]

Mini Pocket Bikes > MTA1 Mini Pocket Bike > Stock Parts - Part Name: Exhaust - Stock, Cag

 

[camlifter]

RATTY ? look at retmachinists pick , that doesn,t look ratty to me

i never said it did. his looks very good, flows with the bike and compliments the over all look of the bike. but a big honking pipe just put on for the best performance offten looks like an after thought and dosen't add to the over all look.
to me a MB needs to be practical, and look good doing it. it dosen't matter how fast it is if it's ugly, if it's so out of proportion that it can't even be pedalled and has to rely soley on the motor for motive power or is uncomfortable to ride it will soon be setting in the corner with cob webs on it.

 

[Venice Motor Bikes]

I used a SBP pipe on my new boardie & I think it looks great with the lines of the bike!!
I did have to cut a little from the header & weld it all together for a cleaner look tho...
This pic of the pipe is before it was finished, (thus, the coat hanger still holding up the end of the pipe.)

 

[OCCstingray]

An expansion chamber is my next upgrade I plan to do to my bike. Only problem is that I am not sure on how it will fit on a stingray. I have a welder, so if need be, I could always cut a section out of the exhaust and weld the expansion chamber in. Where could I get one? I have heard that expansion chambers are the one of the best upgrades for the money. Take a look at the pictures, and tell me what you think, I really appreciate any help.

 

[BarelyAWake]

The three most common choices are already mentioned in this thread, the one Addicted posted a pic of (which I'm pretty sure is a Grubee accessory), the SBP one that seems to have the most favorable reviews, and the somewhat random pocketbike adaptations... which I've always wondered about given most pocketbikes are less than 50ccs *shrug* They tend to be really inexpensive tho heh

There's other options ofc - higher end custom pipes like the SCSW one: http://motorbicycling.com/f23/new-scsw-tuned-pipes-sale-189.html and I think Pirate Cycles has one in development anyways... but those are gonna cost ya heh - there's more ifn ya dig around the forum a bit.

Given my admittedly personal "bias" regarding noise and the adaptability of the setup - I'd recommend the SBP one fer yer stingray, as you have a welder fitting it with or without the silicone hose is no problem.

Here's a pic of a SBP sys mated to the stock exhaust headpipe on my Rollfast build, missing a U clamp and the (extended) glasspack silencer as the bike is still under construction as well as the completely "stock" installation including the spring retention and high temp silicone on my Schwinn (click to view);

 

[Humsuckler]

SBP pipe "up"

SBP pipe "down"

both mounting options had to be custom made as far as hanging it.

for the up configuration

and for down under

 

[Russell]

An expansion chamber is my next upgrade I plan to do to my bike. Only problem is that I am not sure on how it will fit on a stingray. I have a welder, so if need be, I could always cut a section out of the exhaust and weld the expansion chamber in. Where could I get one? I have heard that expansion chambers are the one of the best upgrades for the money. Take a look at the pictures, and tell me what you think, I really appreciate any help.

This may not go by the 12" max rule but the power increase shocked me. I built it to go with the flow of the frame.

 

[OCCstingray]

Hi Russell, I did not realize you posted here, I just posted on another thread asking you about it. You anwered my question though. I just wanted to here from someone who also has a stingray. Thanks for the help, I will probably get mine from SBP, they seem to be the most talked about.