Posted in Uncategorized on December 31, 2012 by vanguardcycles

Some brave souls out there have been making Vanguard Pipes with the plans and instructions that I sell. Click on and scroll down on the link provided, a bit past halfway down the page and you can see Dustin’s pipes! Well worth a look.


Check out the Vanguard Precision website!

Posted in Uncategorized on September 14, 2012 by vanguardcycles

Vanguard now has a site for the machine work/fabrication business. Officially titled Vanguard Precision Grinding and Fabrication LLC, we DBA as

Please check out the site! be sure to go to the Image Gallery for a look at some of our work.


Milling PH 4140.


What people are saying about our machine work.

Posted in Uncategorized on February 6, 2012 by vanguardcycles

Here is some feedback I received from recent machine work we did…

“Just thought I would let all you fellow 2 stroke lovers know about Nate’s work…I had seen the quality pipe work, and viewed his blog. The mill work looked very good, so I contacted him in regards to his RD350 cylinder mill work, where he opened up the intakes for a set of Banshee reed cages, which is a popular mod, but one in which care needs to be taken. I wanted a set of RD400 cylinders done, so I contacted Nate. He had not yet made a fixture to do 400 cylinders, but agreed to do so. We e mailed back and forth a few times, and I sent off my cylinders. Nate kept in contact, and a short time later, I received a perfectly milled set of cylinders matched to the set of banshee reed cages I had also sent. Nate put the same quality work into my cylinders that is shown in all the other work of his I have seen.The price was very reasonably for the amount of work necessary to make a fixture, and carefully modify a set of cylinders. I cannot thank him enough. I recommend his work highly, and plan on having him do more work for me. Doug Schreiber” 

Thanks Doug! pleasure working on your parts.


“The intakes were machined beautifully and the fit perfect. The CNC machining was so much quicker and more precise than trying to hand fit the Banshee reed blocks to my RD350 cylinders. No possibility of a breakout. I can’t thank you enough for the great job and excellent service.” Gene

You’re very welcome Gene!  

AJ’s bike spotted in PA.

Posted in Uncategorized on January 24, 2012 by vanguardcycles

Funny when surfing the web what you can find. Occasionally these suprises come in the form of high quality photos of our own work!

See here-

The pics are copyrighted, so I cant post one here. I am contacting the owner for permission.

EDIT: the owner changed the License so that I can post the pics. Thanks!


Making our Mark!

Posted in Uncategorized on January 24, 2012 by vanguardcycles

Here at Vanguard Cycles we were thrilled to see some excellent design/fabrication happening over in India!

I first saw this

And in that post is a link to Tejinder Singh’s photo gallery here-

V1 inspired headers spotted in India.

We were pleased to get credit for the header style “The headers are inspired by the Vanguard pipes, they look beautiful and fill up the space between the front wheel and the engine” We could not agree more!

Have a look, we think you will like what you see!



Mini Cafe Sleeper Pipe Project

Posted in Uncategorized on December 3, 2010 by vanguardcycles

A 100cc’s of fury? That’s right, we’re huge fans of small bikes with a lot of go, especially when it comes to around town bikes and bar hoppers. This mini cafe bike is basically a Yamaha G6S  with a 100cc YL2 motor transplanted into it and a custom one off  Vanguard expansion chamber to add some serious grunt!

The first thing we decided to do to our G6S is replace the way underpowered 80cc motor. This is the same motor from the popular Yamaha G5 and because of this these bikes are sometimes mistaken for the G5. The vin #s on the frame and motor are stamped G5, and they do share many common features  but the cafe tank and seat combo make this a G6S or G7S and not the earlier YG5.

Either way we decided to ditch the 80cc motor and swap it out with the 100cc engine from a YL2. While it may seem like it’s not worth the hassle for an extra 20cc’s there is quite a bit of difference between the two. The Yamaha factory specs tell the story, the 80cc G6S motor was rated at only 4.5 HP while the 67 YL2 motor was rated at 9.5 HP, that’s double the horsepower right out of the gate.With the addition of the pipe it becomes a whole new bike.

YL2 Motor

After the motor was rebuilt it was time to address the pipe.

The Yamaha exhaust of this era are of poor design, they were more concerned with muffling noise than providing any sort of performance, the stock exhaust doesn’t even have a return cone. They did however look awesome and we didn’t want to lose that classic high pipe look. So we decided to create a custom expansion chamber that would give us a much needed performance boost while staying true to the original aesthetics.

This is a stock G6S exhaust and the look we were trying to keep

And this is our true expansion chamber in sheeps clothing

Our pipe, while similar masks a  hidden baffle cone, and internal stinger and features a one off custom alloy can polished to give the look of the old pipe. We also kept the heat shields  in their original configuration.

The geometry of the pipe was designed by the numbers and if anyone is interested we’ll be happy to provide the specs to any would be fabricators.

Cone Templates

Cones Welded up

After we ran the numbers we decided we could still use the stock header which made things a bit simpler

The overall length of the stock pipe and the fact that it’s a high pipe meant that finding room to get the appropriate TTL was not a problem. We aimed to have a pipe that came on relatively early with a lot of low down power. This is not a high revving light switch pipe but instead comes on quick and delivers even power through out the rev range as intended.

The baffle cone was covered to retain the stock appearance

figuring out the placement of the heat shields

Next to the original for comparison

And finally, fitted with the can and the stock brackets borrowed from the original and welded in place

A little paint and polish and the end result

The end is result is one fun bike that is roughly the size of a Puch Magnum but with a lot more oomph! Quick and light.

If any one is interested in fabricating their own just drop us a line and we’d be happy to provide the numbers and cone templates, just remember all the calculations were done for a 67 YL2 100cc engine

How the Vanguard V1 Expansion Chambers are made.

Posted in Uncategorized on October 1, 2010 by vanguardcycles

UPDATE: dateline January 24th 2012.

These pipes are no longer produced or sold. I very much enjoyed working with John over at Economy Cycle, but time constraints and lack of profitability have caused me to cease production. (If you bought a set, congratulations, you now own a set of very rare chambers!)

I have decided to make the design available in PDF format (for print and cut) and DXF format for laser, plasma, water-jet etc. Purchase will include drawings (templates), dimentions, detailed materials list, and sources.

By purchasing you agree to the following terms (limited use licence)-  Information to be used for yourself only. Not to be used for commercial purposes. Not for resale. Not for electronic or manual distribution. Sharing of the data/design is strictly prohibited. Single use (build) only. You agree to not hold me liable for anything incidental to your purchase of the design, or the building/use/ownership of the  product produced by building the design or any variation of the design. You agree that chambers produced using the design and adhering to the majority of the designs features are to be called Vanguard Pattern Pipes, not simply Vanguard Pipes or Vanguard V1’s. Substantial modification of my design need not be referred  to as  Vanguard Pattern Pipes (this term has the intent of keeping the original pipes I produced distinct from any not made by myself). Terms and conditions subject to change at any time without notice. Furthermore, purchase/use of the designs constitutes your acceptance of all the terms and conditions above.

The basic design is for the Yamaha RD350, that said, the design may be a useful starting place for someone interested in producing their own pipe/variation of my design.

Purchase full drawings PDF/DXF, parts list, sources for only 39.99 via paypal. Please allow 7 days for electronic delivery. Please don’t share the plans. I invested hundreds and hundreds of hours and many thousands of dollars into the  research, design and fabrication of these pipes.

I hope that this Blog/tutorial on how to make these pipes has proven useful to you. If you have enjoyed learning about how these pipes are made, please consider purchase of the plans (even if you don’t plan to build a set) purchasing the plans can be seen as a thank you to Vanguard for making information available to you and the world!

I can be reached at if required.

UPDATE END: dateline January 24th 2012.

I have been building expansion chambers for the past 7 or 8 years. I started with mild steel pipes for single cylinder medium displacement engines and eventually moved into producing stainless chambers for the Yamaha RD350.

Vanguard's V1 Expansion Chambers.

In this post, I will be detailing the construction of my chambers from start to finish complete with pictures. I will not delve deeply into the design of the chambers, as their are many other sources that cover how to design a chamber for a particular engine/riding style.

The chambers are for sale at Economy Cycle

Not just a peak, a plateau!

For the past several years most of this info has been kept close to the vest. Today I am revealing most of the tricks of the trade…

The bill of materials for building these pipes is as follows .250 stainless plate for the header flanges, 2 sizes of stainless tubing for the header stub and the header overlap tube, tubing for the stinger, aluminum tubing for the silencers, perforated metal for the silencers, aluminum caps for the silencers, 2.5 OD thick stainless washer for the stinger mounting flange, stainless (mill finish) sheet, silencer packing material, neoprene washers, stainless springs, nylon washers and misc. stainless hardware.

From header to silencer, heres how they are made:

I started with hand cutting the header flanges for my pipes, but this was very laborious. I ended up having them laser cut from .250 thick plate. the flanges are then hand drilled and chamfered for the spring holes. The laser cut flanges look and fit very good.

Flanges before finishing operations.

Spring mount holes are drilled/chamfered, pre-cut header stubs are tacked in place and finish welded .

Flanges in progress.

Finished flange.

Now that the flanges are done, its time to move on to rolling the header pieces and massaging them into true roundness.

Most of the parts/materials for a set of pipes. Note the header sections laid out flat.

Each one of these pieces was rolled, then tacked, then rolled again and finally trued by hand with brass hammer over the tube suspended between v-blocks.

After straightening with a brass hammer and tube mandrel.

Header building general overview.

The headers contain 20 sections, the last 13 of which are tapered.

A close fit is very important.

Tacked and ready for finish welding.

Lots of tedious welding.

The tedium is beginning to pay off.

I don't do any finish welding without a full Argon back-purge. No "sugar" in my welds! Here is the Argon back-purge setup. Runs from a second Argon tank/reg unit.

Fully welded headers.

If the welding in the picture above looks like it takes a fair bit of time, your right, it does. Two headers takes me over 2 hours of finish welding. If you add rolling, hand forming to perfect roundness and fitting/tacking, the time for a set of headers jumps to around 6 hours. Now you know why most makers use tubing or hydroform their headers!

On to the body of the pipes:

Originally,  I cut and formed my own header sections and cones. I still form the header sections on a slip roll and hand true them, but I now have the cones cut and welded by a company that specializes in this task. They are not cheap, but its the age old, time-or-money equation, and for me, forming the cones is so laborious that farming out the task was worth it. If you have ever tried to bend/roll a 20GA stainless sheet thats 18″ long into a cone, you will see why I hire this part out.

Cones ready to tack.

Cones tacked and belly sections tacked in also.

The belly sections above are 4″OD and do NOT want to stay round.  Look in the upper left of the picture and you can see the slide hammer attachment I use to force the belly sections round as I tack them in place.

Another pic of the slide hammer round-forcing-tool:

Special forcing tool.

Tacking and welding the cones with Argon back-purge.

Extreme care must be used to keep all the parts in alignment.

Next, with great care the parts are tacked to each other. Keeping the cones and belly sections true during tacking is VERY difficult. The fit-up required to be able to “fusion” weld (welding without filler rod)  with 20GA SS is very hard to achieve. All the parts must continually be massaged with a rubber mallet into “true” so that no gaps or out of roundness occurs.  Any gaps will create BIG problems. Gaps will get bigger and melt away as the arc runs over them. Putting metal that has melted away back where it needs to be is not easy! I make every effort to get my fit-up so good, that only occasionally do I need to use any filler rod.

A weld done without any filler rod is smoother and better looking than one done with filler rod. My welds polish up beautifully.

Looking aggressive.

Argon Purge while finish welding.

Putting it all together. Note some pre-polishing was done on this set. Once fully welded, they are quite a pain to polish.

Getting the stance and alignment correct.

Looking like pipes now.

At this stage, the alignment having been verified, the Argon back-purge is setup again and the pipes are finish welded.

Stinger tubes are welded in and the flanges for the silencers are aligned and welded on.

Heres a shot of the tooling I use to bore and drill the 2.5″ SS washers that become the flanges.

Washers and special tool.

The washers are first drilled while held in a set of aluminum softjaws and then bolted to the tool for boring.

The softjaws are also used to drill mounting holes in the silencer caps.

Modified softjaws and special tool.

Silencers are made as follows:

Cut body tubing to length, machine endcap slugs to size, cut and roll perforated metal, assemble and drill and tap 9 holes per silencer.

A neoprene washer is hole punched for mounting screws and goes between the silencer mounting flange and the silencers.

Custom cut Neoprene washers.

Silencer endcap slugs before finish machining.

Silencer body's and endcaps being checked for correct fit and finish post machining.

Completed silencers.

At this point, spring mounting tabs are welded to the headers, header stubs are finish welded to the headers, footpeg mounting tabs are welded to the pipes and everything is assembled and checked for correct fitting and alignment once more.

Everything is then disassembled for cleaning and polishing.

Red carpet treatment!

Nice and shiny!

That’s the nuts and bolts of the process I use. There are countless other steps required that I did not have any pictures of, the most notable of which is the lathe work that is done on the header stub and the piece that welds to the header that is a slip fit over the header stub. Machining on several parts is needed to create the fit that I require.

All in all, many hours and lots of money go into each set. They were conceived as a project for myself, more of a personal challenge, rather than a product for market. Had I designed them for the market, they would have been MUCH simpler, especially the header.

The results:

43 peak horsepower and a spread of 40+ HP between 6850 and 8250! Most available pipes will give you a high number, but a high number is fairly useless if it peaks and then rolls off again. My design keeps the power over 40 HP for a 1400 RPM spread, and over 35 HP for a spread of 2600 RPM!

Power spread.

This chart is from a motor that is running stock port timing/widths and without a widened exhaust port. The transfers were flowed at the transition of the cases and the bottoms of the barrels, the case transfers were matched, the exhaust port had the rough casting cleaned up, corrected squish and is running banshee reeds. 1.8mm timing on Newtronics. Stock carbs.

Not too bad for a motor with stock port timing and widths.


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