project narrative

 Project Narrative

The Inspiration:

Death Valley “Quad”

This project began in November of 2009 in Death Valley when I saw a bike similar to mine with added rear wheels converting it to a “Trike+Plus” or more correctly, a “Quad”.   The Nevada rider was handicapped which was his motivation for making the modification.   I took pictures and ruminated on the prospect of converting my own bike to a quad as well.  At that time, I had never ridden a trike but had talked to several riders about the pros and cons.  Most of my riding is long distance interstate while tent camping off of the bike.  I routinely encounter campground access roads that are quite demanding when riding two-up with a full camp gear load.  The added stability would allow me to explore less improved roads that today I find intimidating and dangerous.  As I age, I have become more cautious.

I had briefly considered a conventional trike conversion but felt the cost was excessive, especially for an older bike like mine.  I currently ride a very comfortable seasoned (dented and scratched) highly reliable 1999 Yamaha Road Star having numerous “experience dings” with 43,000 miles on it.

The Prelude:

I “Googled” trike conversion kits and found one made by Tow-Pac and another make by Voyager that resembled what I’d seen in Death Valley a year ago.  Although they are under the “tike” heading, they actually were “quad” conversion kits employing a removable “outrigger frame” having two extra unpowered roll-along wheels.  These commercial kits are designed to be more or less universal and adaptable to most any bike.

 The kits were well designed and appeared to be of quality construction; however, they were complicated and costly compared to what I had in mind.   Both kits are designed to be very easily removable so that the rider is not permanently committed to the quad configuration.  These designs require a permanent bolt on frame with a hitch into which the second frame with wheels attached can be joined to the bike.  I, on the other hand, was concerned with only a specific bike and I felt a much simpler less complex and less costly design could therefore be achieved.  I was perfectly willing to spend 15 minutes easily undoing six to eight readily accessible bolts to get back to the basic motorcycle configuration when I chose to so do.

After examining my bike and reviewing the pictures I had taken in Death Valley, I concluded that bolting one single outrigger frame to the bike’s hard-points should not be much of a problem.  I was certain that a local welder could fabricate what I needed rather inexpensively.  The suspension, however, presented somewhat more of a challenge.

Since I am not a car buff or much of a metal working craftsman, I consulted my friend Ray Miller at Special Interest Motorcar Restorations in Santa Ana by phone.  He makes living restoring classic cars.  Ray gave me some key words to Google which would bring me up to speed on simple independent suspensions and the associated components.  He suggested that I look at motorcycle trailers and their components for a start.

Research:

After an afternoon on the computer, I had undergone a crash course on hubs, torsion suspensions, wheels and tires.  I had earlier spent time thinking about the general nature of the frame I wanted to build but I realized that my design had to be based on available standard components to avoid costly custom items.

Once I had a general idea of what I was looking for, I began searching Google websites and eBay for components.

I found that rubber torsion axle suspensions appeared to be commonly used on many of the small motorcycle trailer designs.   There are other suspension systems but these are simple and easy to work with.  I recommend the Dexter Axle website http://www.dexteraxle.com/torflex_axles which will give you quite a bit of information on this type suspension.  The suspension comes in various load capacities.  Since the rear wheel of the motorcycle only carries 300 to 400 lbs normally and the weight would now be shared with the two outrigger wheels, I really needed a relatively soft unit.

Torsion Suspension

Protective Cover

The lightest unit I could find was on the Northern Tool website http://www.northerntool.com/.  After an exchange of faxes, I was able to pin down most of the unit’s dimensions.  All of these smaller units were compatible with a 1” spindle wheel bearing/hub, which is one of several standard sizes.  The suspension was rated at 500 lbs (for two wheels, 250 lbs. each) which was the softest I could find.  (Now that I have riding experience with the finished product, I realize that an even softer lower load range unit would have been acceptable had it been available). The independent torsion suspension was one of the more expensive components costing $176 including shipping.  (The photo shows both of the torsion suspension units with protective covers on the axle spindles).

------------------------------------------------------------------------------------------------------------------------------Edition 7 Insert:

Caulked Joint

5”

Intended Cut

Weld Points

Surplus Torque Tube

6”

Once I finished my Trike+Plus, I felt the ride was “stiff” and I mention this in several places in the narrative.  I was never able to find a reliable supplier that made a torsion suspension with a load limit of less than 250 lbs per wheel.  I spoke to an engineer at Dexter Axle about the interior of their torsion tube and its length in proportion to its load range.  There are no lubricants or fluids in the tube.  I wanted to significantly reduce the load range so I decided to cut the torsion tube roughly in half.  I chose a cut location about 5 inches from the outer end that would still leave about 6 inches of tube plus the two weld joints to the base plate as shown in the adjacent picture.  I used my Makita hand held grinder with an abrasive disc and cut deep enough to sever the central square torque rod but not completely through the entire tube.   When I was finished, I used a good grade of black latex caulk to fill the gap.

  I considered this to be a daring experiment but it worked out beautifully.  This effectively reduced the load range by about half and made a dramatic improvement in the quality of the ride.  The harsh stiffness was completely eliminated leaving a really comfortably feel to the Trike+Plus ride.

I now realize that I could have also designed the outrigger frame to be much narrower if I had wished to so do, by cutting off the torsion suspension tube and the associated excess portion of the supporting base plate as well and using this reduced dimension in the subsequent design process.  This would also have reduced the weight of the suspension unit by several pounds.  (Weigh your components as you go along as the information will come in handy later).  If you make this cut early in your design process, you should tap a bolt hole in the exposed end of the central torque shaft and a corresponding hole in the end cover you will be replacing.  By using a bolt slightly longer than the depth of the tap, you can provide positive retention to resist axial pull-out forces without restricting the movement of the shaft itself.

 Keep this in mind as you proceed through the subsequent sections.

I am pleased that I softened the ride and I would urge any builder who is using the 250 lb suspension units to consider doing the same.  However, I personally would still retain the wide unobstructed platform as it perfectly suits my camping needs.  I have seen trikes and quads that have been forced to use “squashed” saddlebags because of the over emphasis on minimizing the width of the unit.  You, as designer, can have whatever you want in choosing the width best suited to your needs.  The quality soft ride will be pretty much the same.

See section 9.0 “Truncated Torsion Suspension Unit” for more details on this option.

-------------------------------------------------------------------------------------------------------------------------------

Hub Components

Hub Assembly

The next task was to locate a wheel hub with a 1” bearing to be compatible with the suspension.  In searching other sites, I homed in on a compatible hub with a 5 hole, 4-1/2” circle wheel bolt pattern rated at 2000 lb. load capacity, quite comfortably exceeding my requirements.  Two hubs cost $54 plus shipping.  These hubs were specified as being compatible with either 8 to 10 inch wheels or 12 to 15 inch wheels … another decision to be made … wheel size?  I ended up specifying a 13” wheel (24” outside diameter) which just looked right to me.  Smaller wheels would have reduced the weight at the extremities of the outrigger frame which in turn, would reduce the possibility of unfavorable dynamics (dumbbell effect).  This is something to ponder! ( I discuss the effect of wheel size on shimmy dynamics in Section 7).  Note for future reference, that these hubs weighed about 6 lbs. each.

Polyethylene Plastic Fenders

While I was at it, I also found a nice looking inexpensive pair of sturdy black high-density polyethylene plastic trailer fenders that were about the right size for my intended design.  My next step was to move to eBay to see if the same components were available at a better price.  Sure enough, I was able to purchase the hub and fenders through eBay at etrailer.com at half the cost advertized on the other websites I’d been viewing.  Only the rubber torsion suspension was not available except through Northern Tools.

Commitment:

The evening of February 25^th, 2010, I sat back and took a deep breath after turning off my computer.  I had just purchased $316 worth of parts on-line (two suspension units, two fenders and two hubs) … I was pregnant … the project was launched!

Think It Through

Before going any further, I decided to think the project through and be sure of the logical steps needed and the order of doing the various tasks.  With the help of a glass or two of wine, I began laying out a diagram of the tasks ahead.   I call this my “flow chart” and it is included in a separate section.  You can get a quick overview of everything ahead by viewing it now.

Detail Design Phase:

The next task was to work out a design that would, of course, be safe and sturdy but would also allow for adjustments once things came together.  For example, I noticed that the commercial designs were able to adjust the height of the outrigger wheels to manage the weight distribution between the bike’s rear tire and the outrigger tires.  This weight distribution significantly affects steering and traction factors.  However, no features were apparent to adjust wheel track alignment and cant in these commercial kits.

There was also the question as to putting the suspension above or below the frame.  Since I did not have bulky hard sided saddlebags to contend with, I had quite a bit of latitude in my choice.  I quickly realized that by putting the suspension below the frame, I could easily use brackets at the passenger footrest position as the major connection point.  I may have chosen the other option (above the frame) if I had to deal with large hard sided luggage.

Wheel Shopping:

13 inch wheel

Some of the commercial designs used relatively small diameter outrigger wheels which gave the final product the “training wheel look”.  I’m sure the wheels were adequate for the job, yet they simply did not look right.  I considered wheel sizes from 12” to 15”.  I wanted to use a wheel size that looked “trike-like” and finally decided upon 13 inch rims in a standard trailer wheel.  A 13 inch wheel is actually 24 inches in outside diameter which means the axle will be 12 inches above grade.  As a general rule of thumb for trailer tires, the outside diameter will be about 1.8 times the rim size.  Also remember that the weight of the tire plus rim increases linearly with the wheel size and added weight is undesirable!

The choice of wheel size is important for my type of design as it is one of the determinants as to the height of the outrigger frame which must clear exhaust pipes, suspension elements and reasonably match the intended attach points on the bike.

I stopped by the local America’s Tire store and found that they had a quality 13” trailer tire 20% cheaper than what I’d been looking at online.  They also had a 13” chrome wheel at half the price of what I found online.  Two tires and chrome rims cost $307 including mounting and balance.  This was the most expensive components that I was to purchase.  (Other builders have subsequently told me that they located even better deals, so shop around).  I decided to order the tires and wheels up front as it would make the task of design easier if I had the items in hand.  It would also help visualize the final product.  I was getting excited and wanted to simply lean the new wheels against the bike just to savor the changes ahead!

Reference Point

Let the Measurements Begin!

Knowing the dimensions of the key parts, I could now mold them into a compatible design.  The basic starting condition for my design was that the outrigger wheel axle would align with the motorcycle’s rear wheel axis.  In retrospect, I have now seen several designs on Youtube that place the outrigger wheel axle either forward or aft of the motorcycle’s rear axle.  They appear to perform adequately but I nevertheless chose to keep all three wheels aligned for my design.  Both the Voyager and Two Pack kits appear to align the rear wheel axle as well.

Carpenters’ Square Measurement Technique

I spent a considerable amount of time examining the bike for hard points to which I might attach the frame.  The task of establishing dimensions began in earnest.  I first used a level to secure the bike in an upright position.  I then carefully marked out the motorcycle’s rear axle position which became my forward and aft point of reference for all subsequent measurements.  I used two carpenters’ squares to establish height and lateral dimensions of points of interest.  The adjacent sketch illustrates the procedure which is quite simple and accurate.

 

Bolt-on Passenger Footrest

Rear Frame Hard Points

The most attractive “hard points” to brace the outrigger frame appeared to be at the passenger’s foot peg area and at the end of the rear fender frame at the saddlebag support points.  On the Road Star, both locations are strong points and have existing bolts which could be easily extended to support an additional strap or plate.

Integral Frame Footrest

However, the foot pegs on my second bike, a Honda Shadow, are solidly welded to the frame so custom brackets needed to be fabricated and welded in their place for that application.  This changes the bike from its “stock” condition but without compromising any basic feature.

Passenger Footrest Hard Point

Height of the Outrigger Frame:

The dimensions of the torsion suspension unit are very important in that it ultimately dictates both the height and width of the final outrigger frame.  I am using the dimensions of the original 500 lb. (250 lb. per wheel) load unit I purchased from www.Northern Tool.com.  A smaller, more compact unit, if available, would result in even more design flexibility.  (See the earlier edition 7 insert and section 9 pertaining to truncating the torsion tube).

Torsion Suspension

Swing Arm Movement

This rubber torsion suspension unit consists of a 10‑½ inch rubber packed square tube from which extends a 6 inch swing arm ending in a 1 inch diameter axle shank.  Don’t be mislead by the online specifications showing an 8” dimension for the swing arm … that is the overall length, not the axis to axis length. 

Protective black vinyl caps cover the wheel axle shank in the adjacent photo.     The torque tube comes welded in three spots to a sturdy steel base plate with bolt holes.  The plate is at a 45 degree angle to the swing arm.  The swing arm is meant to be in a horizontal position when under no load (the bike sitting at rest).  As load is placed on the wheels, the swing arm rotates twisting against the rubber in the torque tube creating a spring-like resistance.  At maximum load (250 lbs per wheel) the swing arm axle moves approximately 2‑½ inches so fender clearance must be provided to accommodate this motion and a “stop” must be part of the frame to preclude overextension.

When the torsion suspension arrived, I noted small differences in the actual dimensions compared with the specifications and I modified my plans accordingly.

Suspension Assembly

I have chosen to use a 13 inch (24 inch outside diameter) trailer wheel.  The axle of the outrigger wheels will thus be 12” above grade.  Furthermore, the outrigger wheel axle will be in line with the motorcycle’s rear axle.  A portion of the torsion suspension unit will be several more inches above the wheel axle.  I employed a design that supported the torsion suspension on an adjustable swing arm suspended below the outrigger frames as shown in the adjacent illustration and in the accompanying drawings.

When I added all of the height consuming elements together, I had a frame whose underside height was approximately 15+ inches above the ground.  Note that the height dimension on your drawings will be reduced by about 1/2 inch when you account for the fact that the suspension will compress by about that amount when you place the wheels on the ground and the wheels are supporting the weight of the frame, fenders and suspension components.  These elements weigh about 86 lbs in total which calculates to be 43 lbs. per wheel which is 17% of the rated 250 lb load range per wheel so naturally, the torque unit will respond by lowering  about 1/2 inch.  (Incidentally, it is desirable to record the weight of all of the individual components if you wish to conduct the shimmy analysis in section 7.2)

(Note that if you elect to truncate the suspension by as much as 5 inches to achieve a softer ride or narrower frame, you reduce the load range from 250 lbs per wheel to approximately 135 lbs.  As a  result, the 43 lbs per wheel at rest outrigger weight will compress the softer suspension by approximately 3/4 inches when the outrigger is at rest, supporting only its own weight.  The system will therefore more easily bottom out on large bumps.  This factor is also discussed in section 9 dealing with the truncated suspension option).

Unfortunately, anything less than 17 inches in height above grade would interfere with my rather large right side exhaust pipes.  This conflict dictated that the outrigger frame be outside the envelope of my exhaust system placing the inner most frame element (A) no closer than 11‑¼ inches from the bikes centerline.

 (See Frame Layout Drawing in folder 2 for the frame element labeling or right click on hyperlink to go to the drawing).    (Hyperlink) 

Since I wanted the unit to be symmetrical for weight and balance considerations, I employed the same standoff distance on the left side as well resulting in a 22‑½ center opening for the final configuration.

I’m sure your bike’s dimensions will be somewhat different but the considerations are basically the same.

Width of the Outrigger Frame

As mentioned above, the original length of the torsion suspension unit’s rubber tube section is approximately 10‑½ inches.  The overall length from the inner end of this tube to the outer end of the 1” diameter wheel axle shank is 18-¼ inches.  The inner end of this suspension unit must clear the right side exhaust pipes with a small margin.    I chose an overly generous standoff distance of 2 inches. This locates the suspension unit laterally.  Adding the hub, wheel and tire dimensions at the end of the suspension’s axle shank establishes the width of this portion of the outrigger assembly.  A smaller exhaust system standoff could have reduced the overall outrigger frame width by as much as 4 inches.

Since I had all of the components at hand (suspension, hub, chrome wheel and tire), I simply laid the assembled group on the floor and measured the overall length (L).  I then added the standoff distance from the exhaust to determine the overall half width of the unit.   (The length (L) could be shortened by up to 5 more inches by cutting off the end of the torque tube and associated base plate to make the ultimate ride softer and more comfortable.  I now highly recommend than one consider doing this). 

Once the width of the assembly had been established, it remained to locate the outermost elements of the frame.  The outside frame member (B) serves two functions.  First, it borders the fender and second, it supports the torsion suspension swing arm.  Placing this frame member at the inside edge of the fender resulted in a reasonable position to support the suspension system as well.  If the frame (B) were much further out, it would interfere with the wheel.   If it were closer in, it would increase the twisting cantilever load from the wheel to the suspension support point.

Notch for Frame

Note that the fender support frames (F) are cut a little short so as to not interfere with the curved outer edge of the fender itself.  The otherwise open ends of these fender support frame members are plugged with black plastic caps designed for this purpose.  It was necessary to “notch” the inside corner edges of the fenders where they rest on the frame as the fenders extend below frame level.    Be careful to leave some minimal clearance between the fender and the frame in the final assembly.  The plastic is prone to fatigue and fracture at the corners of the cut if it rests on the frame.

 The outer edge protrusion of the fenders added another 1-½ inches on each side.  For the Road Star application where I used the full 10 ½ inch torsion tube and a 2 inch exhaust system standoff, this worked out to be approximately 64-½ inches overall maximum width which is typical of the commercially available conversion kits.  It takes a little time to become accustomed to riding such a wide vehicle!  I could have reduced this overall width by 4 inches if I had used less exhaust system standoff and another 10 inches if I had truncated the suspension torsion tubes in the beginning for a softer ride.

Passenger Footrest Connection

Spacer

Length of the Outrigger Frame

The forward extent of the outrigger frame was determined by the location of the passenger foot peg connecting point on the bike so this was rather straight forward.  Note the added bolt spacer to support the passenger footrest at its proper height.  Your footrest arrangement may be quite different than mine.

Rear Clearance

3M Reflective Tape

Cardboard Pattern

The aft extent of the frame, however, was determined by the need to clear the rear fender while avoiding interference with the rear turn signal lights which extend laterally some distance.

After selecting dimensions that appeared to provide appropriate clearances, I cut out a cardboard pattern of the planned frame just to verify the fact.  Fortunately, the nominal frame height passed just beneath the rear turn signals.                      

Metal Shopping:

Industrial Metal Supply

I visited Industrial Metal Supply in Irvine, CA to actually lay my hands on the metal that I planned to use in the design.  A thick walled (1/8 inch 11 Gage) mild steel square tube 1-1/4 inches outside dimension looked sturdy enough for the frame since the basic bike’s frame is 1-1/4 inch circular tubing.  This size gives enough meat to support drilling 7/16 inch holes to accommodate 3/8 inch bolts. 

Gusset

Metal Options

While there, I checked out the steel strap and precut metal gussets (3/16 inches thick) that would also be needed.  For anyone not familiar with the term, gussets are small triangular plates welded inside the frame or strap at the corners.  These substantially increase rigidity and reduce the flexing of a welded joint.

The price for the metal was surprisingly inexpensive and accounted for only a minor portion of the project’s final cost.

I bought two good 7/16 diam. metal drill bits and several metal cut-off wheels along with a can of black metal primer while at Industrial Metal Supply,   I also bought two metal “rod end” fittings for use in the “torque adjustment” assembly which I will discuss later.

Bracket Fabrication:

Cut-Out Patterns

I bought several standard pre-cut 3/16 thick 4 x 4 and 6 x 6 steel plates, a short length of 1‑1/2 inch thick wall tube and some scrap 2”x 2”x ¼” angle while at Industrial Metal Supply.  This was the material I needed to fabricate the brackets that were to join the outrigger frame to the bike.  It is desirable to use 4 inch and 6 inch dimensions for the plate designs whenever possible to minimize the amount of metal cutting required.  I made a drawing of the plates and then cut them out and held them up to the bike where they were intended to go, looking for any possible interference. 

Lateral Brace (Optional)

The Road Star passenger footrests are secured to the bike’s frame by several large metric bolts which make an ideal attach point for the outrigger frame.  A 1‑1/2 inch tubular bracket ending in a 2 x 2 x ¼ inch angle mates the footrest plate to the outrigger frame.  The right and left side are of the same dimensions (except for dimension X) but the mirror image of one another.

Once I removed the existing passenger foot rest hardware, I made an overlay tracing of the bolt holes to get their exact location.  Before starting to cut metal, I again rechecked all of the dimensions for accuracy.  I then completed the final drawings of the plates (see Passenger Footrest Plate Drawing).  The dimensions shown are specific to my bike but illustrate the process.  I drilled slightly oversized holes to accommodate the metric bolts and to provide a little “wiggle room” for small errors.

Lateral Brace

I needed two sets of plates, one on top of the other.  The “passenger footrest plate” supports the heavy gauge 1-½ x 1-½ thick walled square tube at its top that directly supports the outrigger frame.  The second “lateral brace” bracket supports a diagonal strap that reaches under the right side exhaust pipes and connects to the outrigger frame in such a manner as to give it added rigidity.   At first glance, one might think that a single plate supporting both brackets would suffice; however, it would then not be possible to assemble such a design without actually removing and replacing the exhaust pipes in the process!

In hindsight, I now feel that this second supporting diagonal lateral member is optional as the frame proved remarkably rigid on its own.  This diagonal lateral brace also protrudes about as much as the saddlebags when reverting back to the basic motorcycle configuration and is awkward.  Doing away with this diagonal lateral brace also eliminates its associated mounting plate and further simplifies the design.  I did not consider the lateral brace on the lighter Honda adaptation and eventually removed it from the Roadstar as well.  On the other hand, if you encounter any low speed shimmy, this added rigidity may help minimize it.  It is your call!

By making a cardboard pattern of the mounting plates first, I was able to confirm those areas that required cutouts to avoid interference with other parts of the bike.  I then made print copies of these patterns and pasted them onto the metal stock before drilling and cutting.  I rounded and smoothed all edges and used a counter sink head to smooth out all drilled holes to give the finished product the quality machine shop look I desired. I then fine sanded and cleaned up the metal with acetone to remove grease and other oils and prepare them for eventual priming and painting.

Delay Decisions Were Possible

I next sat down and considered the sequence that I should do certain assembly tasks, anticipating that the “as built” frame would probably slightly vary from the “specified frame”.  I concluded that I need not commit myself to certain bracket dimensions until I had the frame in hand.  Then I could accurately specify those dimensions with confidence and finish the job.  However, by delaying these decisions, I would have to make two trips to the welder rather than just one.  The “Flow Charts” provided in the Folder 3 reflect this sequence.

In particular, the “exact” distance from the passenger’s footrest plate to the outrigger’s frame connecting bracket (dimension X in the earlier sketch) is best determined “after” the frame has been welded to allow for minor assembly variations.  It turns out that for the Roadstar, X is not the same dimension right and left side.  It is important that the outrigger frame slip easily but accurately into place to make the “on-off” option viable.  It is also essential that the frame be in perfect alignment with the motorcycle to preclude unwanted dynamics.  This is especially true for frame elements B since they support the suspension components.

Purchase Material

I felt that I was now ready to cut out the frame elements so I purchased the basic frame 11 GA. 1-¼ inch tube stock (20 feet) from Industrial Metal Supply.  Stock comes in 10 ft. lengths, two of which are within inches of being adequate for the frame I had designed.  The additional few inches came from the remnants bin.  Surprisingly, the steel for this part of the frame cost less than $35.

Perforated Plate

I was concerned about the openness of the simple frame design to the roadway and was pleased when I came across 16 gage perforated steel plate stock sold in 24” x 48” sheets with a ¾” hole pattern.  They also had preformed edge channel in 10 ft. lengths to give a finished look to what would become the platform of the outrigger frame. I eventually had this platform tack welded to the finished frame.   This is a luxury in that it is not structurally necessary but the total cost of the platform materials came to only $90 and it certainly looks great!  Welding the platform in place added some very small additional cost that was buried in the total welding bid.

The total cost of the metal used in all elements of the frame was approximately $125 with the optional platform being the major contributor.   The metal is obviously a relatively minor portion of the total project cost.

Frame Cutting:

I carefully laid out the frame members for cutting in a specific order so that I would not waste material.  This took about 20 minutes of juggling segment combinations to most efficiently use the stock at hand.  (See the cut length layout diagram).  If you don’t enjoy puzzles, just forget it and buy some extra tubing … it’s cheap.  As it turned out, I used all but two or three inches of the two 10 ft. tubes I had purchased.  I purchased several metal cut-off abrasive discs to use on my Makita hand held grinding tool.  These seem to work quite well.  I also tried an abrasive cut-off blade on my 10 inch miter saw but this worked poorly, heating and melting the metal while leaving a poor edge.  Cuts were also much slower, the blade seemingly less effective compared to the higher speed handheld tool.

It proved quite difficult to accurately cut exactly 22.5 degree and 45 degree angled ends with the hand tool.  I had to finish each angled cut on the grinding wheel to properly square the ends.  I found it more accurate to first mark and tape and then cut the periphery of the tube rather than trying to cut straight through the member.  As instructed by the welding websites I visited, I slightly beveled the outer edges of the frame members that were to be joined to prepare for the weld fill.

Pre-weld Frame Layout

I am not familiar with cutting metal so I was very cautious and wore a good face mask, heavy gloves, an apron and a shirt with thick sleeves.  Cleaning up the metal dust afterward was a chore.  The hot grinding debris from the handheld tool actually burned out the threads in the fingers of my gloves after several hours.  Small hot metal corner cutoff pieces landed on my rubber floor pad and promptly melted into the mat.  I made such a racket that I eventually bought my neighbor a bottle of champagne in appreciation of her patience and endurance.

When I finished cutting each frame member, I labeled it with its identifying letter and marked an arrow to identify its orientation (i.e.: forward or inside direction as may be the case).  I laid out all of the members and found a minor error in one of my measurements.   I had used the wrong reference for the dimension.  Fortunately, correcting the problem only required “shortening” the members in question which was relatively easy.  (Metal does not stretch well)

Pre-weld Platform

I took digital photos of the assemblies to help the welder visualize the final product when giving me a bid.

I next laid out the perforated metal sheet platform and its associated metal edge channel for cutting and assembly.  The perforated sheet came in a width of 48 inches which was perfect in that I needed two 24 inch wide panels.   Unfortunately, the channel edging is only sold in 10 ft. lengths and is expensive ($31 per 10 ft.) and none was to be found in the remnant bin.  I ended up with about 5 ft. of edge channel scrap.

Frame Bolt Holes & Gussets:

Once the frame sections have been welded together, drilling bolt holes would have to be done by using a hand drill which is slow and arduous.  Since I was confident of the location of the main passenger footrest and rear saddlebag bracket bolt hole locations, I went ahead and drilled these holes on my drill press while the frame members were easy to handle.  These holes are all on the innermost rail of the outrigger frame (element A) and would not be affected by minor frame distortion stemming from the heat of welding.

I also drilled the holes for the suspension system swing arm and pivot bolt.  Be very careful to insure that these holes are drilled true and aligned properly otherwise the entire suspension will be askew and a multitude of problems will ensue.  

Plastic End-Cap

I did goof on one hole location but plugged it with a black plastic 7/16” insert to be found in the specialty drawers at most good hardware stores.   I also found black plastic square plugs properly sized to fit the open ends of the 1-¼ x 1-¼  11 GA steel tubing.  I secured these with “goop” to prevent rain and moisture from collecting inside parts of the frame.  This nice touch added only another $7 to the project.

One word of caution.  The edge channel for the perforated platform is only 1” wide while the tubular frame is 1-¼” wide.  To obtain the cleanest bolt holes, I drilled them ½” from the edge to center them on the edge channel rather than centering them on the frame.

I next cut the eighteen 2” x 2” corner gusset plates (from the 4” square plate stock) that would eventually be welded in place for added corner strength.

Swivel Rod-End

Rod-End Provisions

The hardest task was cutting a slot in the bottom of frame element B to accommodate the “swivel rod end” that is part of the suspension torque adjuster.  This is a useful load bearing item incorporating a center swiveling bearing that is securely mounted by a 3/8” bolt inside the 1-¼ tubular frame as shown in the adjacent sketch.  It fits perfectly!  (The adjustment link shown in the sketch is rotated 90 degrees to best illustrate the connection details.  These link brackets were made from 3/16” x 1” strap material.  Be sure to leave enough clearance for a box wrench on the inside nut).

Slot

The gap through which the 3/8 inch diameter threaded end protrudes must accommodate some angular adjustment range hence the hole must be slotted.  It must also be wide enough to accommodate the width of the end bearing at its center so it can be easily inserted into the frame.  I drilled three 5/8” holes in a row and patiently filed the edges to create the required rectangular slot.  The high strength 3/8” swivel rod ends, which I purchased at Industrial Metal Supply, are conventionally used in rigging projects and were relatively expensive costing $11 each.

Nuts, Bolts and Washers:

I stopped at McFadden Hardware in Santa Ana and bought the nuts, bolts, washers and lock washers that I needed.  McFadden is one of the better industrial hardware stores in Southern California with an extraordinary inventory of fittings.  I used “loctite” to secure all bolts on final assembly.

Ray Miller at Special Interest Motorcar Restorations advised me to use Grade 8 bolts on the frame for added strength and durability.  Ray felt that lock washers were a better fastener choice than nylon nuts for high dynamic load applications like mine.  He also advised me to use stainless steel bolts for the fender attachment as they would show and would otherwise be prone to rust. 

The total cost of all of the nuts, bolts, washers and lock washers was a surprising $45 … much more expensive than I had expected.

Reworked Passenger Foot Rests:

New Footrest Bracket

Height Spacer

I removed the original passenger footrest hardware to facilitate the connecting brackets that would bolt to the outrigger frame.  To restore a passenger footrest option, I had to fabricate new attachment items.  This was simply done by making two small U-shaped brackets for the footrest pin and welding them on to the outrigger frame support bracket.  If you are going to do this sort of adaptation, have your parts to be welded at hand to avoid a second trip to the welder. Your hardware will most likely be different than mine.

I added a short metal spacer to extend the outrigger attachment bolt in order that it could raise the footrest to the correct riding height.  I put a glue-on plastic bumper atop the bolt to prevent rattles.

 Rear Fender Saddlebag Brackets:

Clear Bike Suspension & Exhausts

In addition to the forward passenger footrest attach point, I made two vertical brackets on each side that ran from the outrigger frame to hard points on the rear fender where the saddlebags attached to the bike.  These additional brackets help distribute the outrigger frame load to the bikes frame and added additional rigidity.  I welded gusset plates at each bend of the bracket to further increase their rigidity.  These brackets also serve as a standoff support for the saddlebags both in the “quad” configuration and in the basic motorcycle configuration, replacing the stock chrome saddlebag standoff bars I had previously employed.  The brackets are obscured by the bags when in place.  These vertical brackets were dimensioned to clear the bikes rear suspension swing arm and the exhaust pipes when the bike’s suspension was fully compressed.

All Ready to Weld

Pre-weld Swing Arm Hardware

Final Drawings and Specifications for Welding

When I had accumulates all of the items to be welded (frame elements, brackets, straps, gussets, footrest supports and suspension items) I began to shop for a welder in earnest.  I hoped to get nearly all of the welding done at one time rather than traipsing back and forth with small (more expensive jobs).  I had earlier decided to hold off on specifying the length (X) of the main brackets that connect the outrigger frame to the bike until the outrigger frame had been welded thus allowing for small dimensional anomalies.  This would become the final welding task.

I compiled the final drawings and photographs that I thought would be useful to the welder and went about getting three estimates.  My metal supply house (Industrial Metal Supply) recommended a local welder as did my auto expert, Ray Miller at Special Interest Motorcar Restorations.  I chose the third local welder (Specialized Welding & Fabrication) from local ads and reviews on the internet.  I was pleased that I received the most reasonable estimate of $500 from David Stiles at Specialized Welding & Fabrication since he was my first choice and is clearly a heliarc craftsman and artist when it came to metal fabrication.

David Stiles - Welding Craftsman

Messenger Wire

I took all of my miscellaneous parts to Dave’s shop and we started the welding process at 9 am. on a Saturday morning.  We finished 9 hours later!  We worked together, keeping the parts straight and carefully squaring up the sections before welding.  I was careful to properly fish my tail light messenger wire through the frame elements as they were welded together.  It is also crucial that frame B right and B left be parallel as these elements support the suspension which must track perfectly to avoid dynamic problems.  Some builders have added additional forward or side LED running lights to the fenders.  If you want internal to the frame wiring, additional messenger wires and passage holes will be needed.  PLAN AHEAD!

Welded Frame

The job took a lot longer than either one of us anticipated.  The welds were beautiful and the frame was perfect in dimension!  I feel that you would be fortunate to get the same job done for twice the price … so be prepared for higher bids.  I also walked away with a lot more knowledge about welding plus some great past project war stories from Dave.

Powder Coating:

I had originally planned to prime and paint the frame; however, Dave Stiles convinced me that powder coating would result in a far more durable weather proof finish.  He suggested that I get hold of Bob Goldberg at Performance Powder in Anaheim, California and check it out.  This is quite a large company with substantial facilities.  Dave was optimistic that I could tag on to the coattails of some larger job if I’d settle for the coating color they were applying that day and, by so doing, get a reasonable price.

This is exactly what happened.  They were running a large black semi-gloss fast cure job the morning I arrived.  Bob Goldberg had done a number of coating jobs for Dave Stiles and he was always impressed with the outstanding quality of Dave’s work.  He gladly tagged my small frame coating job on to the larger batch, charging only $100 for the process.  Here again, I’d be prepared for a higher cost if you simply powder coat the frame as a standalone item.

I had my frame back the next day and it was beautiful!  Bob did suggest, however, that I run a bead of black silicone based sealant along the channel edge of the perforated platform as it is very difficult to effectively get into such a small crevice where water could collect.  He also assured me that semi-gloss black spray paint would touch up any future road damage and that it would blend and adhere perfectly well.

I did not powder coat the other plates and brackets.  Instead, I gave them hefty priming with a multiple semi-gloss black paint final finish.

Final Assembly & Alignment

Wheels to Frame

Final Assembly

Attaching the wheels to the now assembled frame and suspension was a real milestone!  This contraption was finally starting to look like a “Quad”!

Frame to Bike:

This is a crucial step.  For the sake of discussion, let us assume that your frame is not perfect.  Let us assume that it is not exactly square or some of the elements are not quite parallel with one another.  What part of the frame do you align with the bike?  Your best choice is to concentrate on the frame elements B on which the wheel suspension unit is mounted.  If both the right side and left side frame B elements are parallel to the bike’s centerline, the wheels will likely also be in line.  If they are not parallel, split the difference and you will minimize the amount of wheel track adjustment that will be required later.  In the end, the frame and wheels must be properly aligned for good safe riding properties.  This may require reworking the rear fender support strap brackets to exactly match the final frame position.

An easy way to check this frame alignment is to place a long level or other reliably straight member atop frame element B.  Then measure the right and left equidistant standoff distance from some symmetric part of the bike, such as the outer edge of the crash bars as shown in the adjacent photo.  When you’ve got this right, measure X_RIGHT and X_LEFT and finish the footrest connecting brackets.

Wheel Height (Torque) Adjustment Range:

It is desirable to be able to adjust the outrigger wheel height to some degree.  By raising or lowering the wheels relative to the frame, you can shift the amount of weight being carried by the motorcycle’s rear tire which in turn affects the bikes steering and rear wheel traction.  This is a unique feature of a “Quad” with independent rear suspension, unlike a “Trike” which has only limited suspension adjustment options.

No Load

Full Load

I spent some time developing a swing arm scheme to allow the adjustment of the outrigger wheel height (pre-load).  My goal was to keep it simple and use as little “custom” hardware as possible.  One of the commercial kit schemes is rather complicated and results in a member protruding well below the rear wheel assembly.  That protrusion significantly reduces the ground clearance of the bike.  (Remember your swerving ability will now be limited and you will have to deal with debris on the highway).  However, that system covers a wide adjustment range probably to accommodate a variety of motorcycles.  I am dealing with only two bikes so the adjustment range requirements are lessened. 

I have chosen to use a 13 inch (24 inch outside diameter) trailer wheel.  The axle of the side wheels will actually always be 12” above grade as the wheels will always touch the ground.  Only the pre-load distribution between the motorcycle and the outrigger changes.

The lowest point for the outrigger wheels relative to the motorcycle would correspond to no load on the bike’s rear tire (bike’s swing arm drooping fully extended below fender) and the total rear end weight resting on the outrigger wheels only.    This would be analogous to jacking up the bike’s rear end by using the outrigger wheels.  Call this Condition A.  In this extreme condition, the front end would be heavily loaded resulting in solid steering and front braking.  However, the motorcycle’s rear wheel would have no traction whatsoever.  This also results in the stiffest ride.

The outrigger wheels will be at their maximum height relative to the bike when the bike’s own suspension is fully loaded and compressed (bike’s swing arm pushed high into the bike’s fender) and the outrigger wheels are not carrying their own weight.  The outrigger assembly’s total weight(including wheels)  is 164 lbs.  The bike’s rear end is essentially carrying the entire weight of the outrigger assembly and the overall center of gravity correspondently moves aft.  All normal riding conditions require the outrigger wheels to be lower than this position.  Call this Condition B.  In such an extreme situation with most of the weight on the motorcycle’s rear wheel, the front end would be comparatively lightly loaded and the steering would be soft and unresponsive.  However, the rear wheel would have maximum traction and braking ability...  This configuration results in the softest ride.  (My final setting was biased in this direction).

Suspension Swing Arm Assembly

Over-extension Stop

Height Adjustment Link

Swivel Rod End

All possible outrigger wheel adjustments will fall between these two extremes of condition A and condition B.  This establishes the absolute maximum usable adjustment range.   For my heavy Road Star, 3 inches of adjustment proved adequate to cover the useful range.  You may wish to consider a larger range to cover other contingencies unique to your design.  If you feel you need more adjustment range, you can always fabricate longer or shorter height adjustments links.

Although I like to think of adjusting the outrigger wheel’s height, in actuality what is being adjusted is the at-rest suspension unit’s torque.  The wheel height above the ground remains unchanged but the outrigger torque suspension is pre-loaded to transfer weight to or from the outrigger tires.

The mechanical principle of this “Suspension Torque Adjustment system” is quite simple.  The suspension unit has a strong base plate angled at 45 degrees from horizontal.  I built a swing arm with a mating plate welded to it to allow this entire unit to swing in an arc from a 3/8” pivot bolt on the outer frame element B.  Note the added reinforcing plates to be welded to the upper end of the swing arm and the frame at the pivot bolt bracket.  It is crucial that this assembly be “square” from the beginning!

At the lower end of this “swing arm”, I attached an height adjustment link leading to a swivel rod-end which is interior to frame element B.  As illustrated in the adjacent sketch, one can raise or lower the outrigger’s wheel axle position relative to the frame (preload the suspension torque) by lengthening or shortening this adjustment link.  Shortening the adjuster preloads the outrigger wheels, placing less weight on the bikes own rear suspension.   About 3 inches of adjustment covers the range of interest for my situation.  If you feel the need for a greater range, change the dimension of the adjustment link to suit you.

You’ll notice that an “overextension stop” has been welded to the bottom of frame element B to arrest the suspension axle arm before the wheel would hit the top of the fender when the rig was under extreme load.  For my particular application, a 1‑½” square steel tube yielded the correct overextension stop position.  Other designs may require different stop dimensions.

Complete your wheel height (pre-load) adjustments before taking the next step of wheel alignment.

Wheel Alignment:

The next task is to insure that the outrigger wheels will run true.  To accomplish this, I provided two other adjustments that allow the suspension unit to be aligned vertically (cant … lean in or out) and horizontally (track … right or left).  This results in three

Alignment Bolt Tabs

Alignment Bolt Assembly

dimensional alignment control … height, cant and track.  I fabricated a series of bolt brackets that are bolted at their lower end to the innermost lowest corner of the “suspension base plate”.  The upper end of the first bolt bracket leads to a welded bolt tab under the frame at the main passenger footrest attachment bolt of frame element A.  The second bolt bracket leads to a bolt tab under the frame at the bolt location for the foremost rear fender mount support strap on frame element A.  By adjusting these two bolts, one can change the cant and track of the wheel.

Because of the three dimensional aspect of this assembly, it is difficult to clearly illustrate.  The bolt tabs at the upper end are welded to the underside of the inner frame element A while the lower end brackets are bolted to the most outboard lower corner of the suspension base plate.  In forming these brackets and tabs and welding them in place on frame element A, one must make careful note of the three dimensional alignments required.  The bolt tabs are welded in place in order that the frame may be temporarily removed from the bike without effecting the wheel alignment.  Welding of these tabs would not be necessary if the outrigger frame was to be permanently attached to only a single bike.

The wheel cant is changed by shortening or lengthening both adjusting bolts.  The wheel track is changed by shortening one bolt and lengthening the other.  Wheel height is adjusted as previously described and should be done prior to any other adjustments.  When making these adjustments, other bolts (such as the swing arm pivot bolts) should first be slackened to allow the entire assembly to relax and easily adjust to the new settings.  Jumping up and down on the platform and rolling the bike back and forth during the process helps the adjustments settle in as you work.  When everything is true, lock down all of the bolts.

The detailed procedure for checking the alignment is discussed in a later section relating to the bike’s dynamic performance and potential shimmy problems (Section 7.1).

Fender Bolt Brackets:

Face Plate

Fender Bolt Tabs

Cap

The base of each plastic fender is secured by using three fender bolt tabs welded to the frame.  Stainless steel ¼ “ bolts and lock washers with backup stand-off nuts secure each end of the fenders.  A narrow steel face plate distributes the bolt load least the plastic become overstressed and crack.  I took care to angle the bolt tabs about 10 degrees so that the bolts would squarely meet the slightly curved fenders.  Have these tabs ready for the welder when the frame is to be assembled.

Fender Tail Light Wiring:

Once the frame is assembled and welded, it would be extremely difficult, if not impossible, to fish wires from the bike’s tail light area to lights on the fenders.  Most of the commercial designs simply secure exposed wires to the underside of the frame.  To facilitate cleaner internal wiring, I made sure a hole was drilled in those frames where the wires must pass through before assembling and welding the frame elements together.  This means a hole must be drilled in frame member A where it meets member E and a hole must be provide in frame member H near the bikes tail light assuming this is where the wires will enter.

I fished a messenger wire through the frame elements from the center hole near the tail light to each of the fender locations as the frame was being welded together.  After the frame had been welded and powder coated, I simply joined the messenger wire to the electrical wires and pulled them through, saving a lot of grief.   In the photo, you can see the finished wires extending from a hole I drilled in the plastic cap at the end of the fender support frame E.  If you are planning additional lights and would like internal frame wiring, you should include additional messenger wires and passage holes in the frame at the appropriate junctions.

After endlessly shopping for suitable tail lights, I decided to save some money at bought a pair at Big Lot discount store for $18 compared to the $100 each deluxe versions on line.  They are “good enough” as I am interested in Go, not SHOW!  While I was at it, I took another builder’s idea and installed yellow LED running lights from Pep Boys auto store on the front of each fender (another $16).  The running lights were an unanticipated addition hence I had to run the wiring externally beneath the edge of the platform to reach the front of the fenders.  Ah yes, plan ahead!  I do have blue LED engine illumination lights on the Yamaha Roadstar but decided against putting one or two under the fenders of the outrigger … just “too much trouble now”!

You will note that I applied 3M reflective tape to the rear of the outrigger frame to maximize night visibility.  I subsequently pinstriped the tape and the fenders as well.  It may not be the “coolest” thing to do but after 50 years of riding experience, I’ve had enough rear end close calls as to be very conservative.  Fortunately, the quad presents a much larger image to the point that even cell phone/texting distracted drivers just might be more likely to notice me.

The Final Touch:

After six weeks of part time work and the total investment of approximately $1500, I proudly applied my name plate to my Trike+Plus!

The Finished Product First Ride:

Yamaha Road Star Trike+Plus

I completed the final assembly and carefully rolled out of my driveway for the first test ride of this new creation … quite an experience.  When I say “rolled”, I mean it.  With no kickstand, the quad easily rolls away on even the slightest incline.  I quickly learned to leave it in gear when

parked.  I fired up the bike, slipped into gear, let out the clutch and almost ran into the home across the street!  Wow!  The handling is totally different from a motorcycle!  I was accustomed to the feather touch of a motorcycle and push-to-steer.  I’ve said it elsewhere in this narrative but I’ll say it again … riding a trike is so different that it is like starting all over again.  The street smarts carry over but the handling is completely new.

Honda Shadow

I had initially set the wheel height (torque preload) adjustment to maximize the load carried by the outrigger wheels.  My first test rides exhibited an overly stiff feeling at low speed.  I eventually solved this problem shifting more load to the bike’s suspension and by truncating the torsion suspension system which significantly softened the ride (See Section 9).

I also encountered a slight low speed front wheel shimmy at exactly 22 mph. when I hit a bump or encountered rough pavement.  I progressively unloaded the outrigger wheels thereby placing more load on the bike’s rear wheel.  By doing this, I smoothed out the ride somewhat but was unable to totally eliminate the low speed notch shimmy.  I discuss this in a separate section entitled “Shimmy Problems (Section 7.1)”  I finally did mitigate the low speed notch shimmy but it required very careful alignment and the addition of a front fork damper.

Camp Ready

True to plan, it took me about 15 minutes to install or remove the outrigger frame from either of the bikes (Yamaha or Honda).  This is a major motivation and essential feature for doing a Trike+Plus conversion.

The real test and my principal reason for undertaking this whole project, was to achieve a satisfactory stable camping vehicle.  This is the reason that I favor the wider platform even though it could have been made narrower.  I have full saddlebag compatibility and I was delighted with my new found flexibility and bulk storage capacity.  No need to tow a trailer and no reason for a skimpy sleeping bag and mat.  At last, luxury was ours!

Remember, added volume capacity is great but to