The Pedicab Trailer

The Pedicab Trailer was my biggest build to date.  More planning, design and build time went into this build than anything thus far.  I built the pedicab trailer for the purpose gifting rides to citizens of Black Rock City during Burning Man 2014.

The pedicab trailer build was started in April 2014 and completed in June 2014.  After completing the project I immediately began work on a tow bike in order to pull the pedicab trailer.  You can view the tow bike build here: Gitche Gumee Tadpole.

pedi 1

pedi 3

pedi 2

rig 1

Raw materials

Raw materials. Bed frames are a good inexpensive source of metal for various projects. The angle iron used on most bed frames is typically 1/8″ thick steel. I pick up used bed frames from thrift shops and Craigslist. I’ve found them ranging in price from $10 – $20. I even found one for free on Craigslist’s “Free” section. [Hint: keep a magnet handy in your vehicle so that you can ensure the metal you are acquiring is made of steel. You want it to be steel so that you can weld it.]

1947ef022a233417f78580ac044ce72c

Prep the raw materials

Prepare the metal. Remove the bed frame wheels, corner braces, clamps and brackets. Whether you cut them off or grind them off, try to salvage as much of the angle iron as possible. Throw the wheels, brackets and braces in your scrap bin. These may be used later for other projects.

a8be636b2c728ca48a08eb13cd9296d3

Plan and design

Before making a single cut plan and design your build to as much detail as possible. I start with an idea. I then sketch rough drawings where I play with the design and modify the measurements as needed. Then I place my final draft and measurements into a design tool in order to render a scale drawing. [Note: I use Google’s free design tool, called SketchUp.]

 

296b81ce0b762e5d706e18781cc6d8a5

Laying out the bottom frame

This pedicab bottom frame measures 40″ wide by 45-1/2″ long. I mitred the corners with 45° cuts. [Hint: I read a tip on the internet that recommended cutting the miters at 46°, rather than 45°, in order to leave a small gap for welding purposes.]

9dd8acd3e3beed2540eee14e4fff553e

Tack weld

Tack weld the outside corner. The will allow you to make adjustments to square each corner as you move from corner to corner.

142c1acc3ffd7ae571c1e8e37d15a3a4

Visualize along the way

I frequently lay out pieces and props during the build process to help visualize the end product. Doing this also allows me to catch (and rectify) problems that might arise further down the line.

3bc978634b3fef61011f0e3f1221da1e

Prototype

Laying out pieces and props throughout the build helps to ensure that your paper design is actually going to work and that your dimensions are workable.

64ac201726eb5197d45d35d8ec66f5fe

Keep the workplace clean

At the end of each day’s or evening’s build session get in the habit of cleaning up your work area. In that way you are able to start fresh and clean for the next session. I always pick-up, sweep, vacuum metal filings and weld splatter, and even put back my tools at the end of a day’s build. Depending on the size of the project and your available time, it may take days (or even weeks) to complete. A clean workspace is a happy workspace. 🙂

904140d7619edf1f6e9596db2ee252dd

Sourcing dropouts

Wheel dropouts for builds can come from a variety of sources. Often the dropouts are hacked from the frame of donor bike from whence the wheels came. However, as can be seen in the photos of the forks, those dropouts are offset in an angle. I need straight dropouts for the pedicab, so those wouldn’t do. Next I looked through my stockpile of donor bikes for two identical sets of dropouts (the pedicab has two wheels after all).

16dc0eab7cc362d9544ba400e54948a4

When you can’t source the part, make the part

I happen to find a couple bikes with identical dropouts (pictured), but then I decided not to destroy the two frames. I also considered using a couple of the braces that came off of the salvaged bed frames. Ultimately, I decided to make (rather than hack) my own dropouts for the pedicab wheel. [More details on these to follow.] By making my own, I can ensure they would fit the frame and wheels perfectly.

153ebe6dd397b60f3b5c44daf340ff30

Fabricating the dropouts

I fabricated the dropouts for the pedicab’s wheels from the same angle iron from which the frame was built. I drilled and cut holes to match those that were in the stock forks from which the wheels came. The dropouts were then welded to the underside of the pedicab’s frame.

75f3e606898cc50365422645a12e0975

Ensuring alignment

When welding the dropouts alignment is crucial. [You want your pedicab to roll straight and have no wheel scrub.] Use the wheel or a spare axel to ensure alignment between the two drop outs. Note also the use of a square to ensure alignment of the axel to the frame.

b4cdbead98c0a4a03ce78659aae718e2

Seat bottom

Building the seat. The pedicab’s seat was built in the same manner as its bottom frame. The four sides were cut and mitered at 45°; clamped and squared; tack welded at each outside edge; checked for squareness again; and then welded completely.

60219001b0ed0f70f76e0bae99bb2690

Setting up the weld

Setting up the seat legs for welding. C clamps at each top corner are used to hold the legs in place in setting up the weld. The piece of angle iron on the floor is being used to spread the seat legs the appropriate distance to insure the legs are perpendicular to the seat bottom. With the legs perpendicular (both in the left-to-right direction as well as the front-to-back direction, the seat bottom should be level.

72a26fc8f0dd1eeaac033efe160e305b

Taking shape

This is the partially completed [no seat back yet] seat resting on the pedicab’s bottom frame. [Props are no longer needed to visualize the end product. Yay!] Notice the rear legs are very tall. That is because they will also hold the cross supports that create the seat’s back. I wanted the entire back of the chair from top to bottom to be one piece for simplicity.

910e3f007c67d601da6a4127caff95c3

Keep extra supplies on hand

Also ran out of welding wire. Off to Harbor Freight Tools for more. FYI, I use a 90-amp flux wire welder for my bicycle-related projects. I run 0.035″ flux core wire through the welder. [Hint: Perhaps it’s good idea to have an extra spool of welding wire (or rods) on hand prior to starting your project.]

a7bbc5404112800865b5cb5c268aa6ac

Making the seat removable

Attaching the completed seat to the bottom frame. There are a few ways to attach the seat to the frame. I could have welded it directly to the frame. However, at that point, it would have been fixed (i.e. non removable). For portability purposes I wanted to be able to remove the seat from the frame, if needed. To achieve this functionality, I would need to bolt the seat to the frame. Here you can see some trusses I built and welded to the frame on which to bolt the seat.

b7bcd3e40ac4aa9259bd3ed9f4505f7c

Seat attachments and trusses

Upper right: The pieces to make the seat-to-frame attachments and trusses. Upper left: seat attachments bolted to the seat legs. No better way to ensure proper placement of the attachment for welding. Lower left and right: Attachments in position on frame. Ready to weld. (Hint: tack weld each attachment (4) on the inside edge prior to fully welding.

4276c403b32e904aecfeda72ac7e7e90

Seat attachments and trusses

Because the seat attachments were welded to the frame only on their inside edges [so that the seat legs could slide all the way down to the frame on the outside of the attachments], I added trusses (in blue) for strength.

14f3d003067103317fb75d2c9df20613

Strengthening the frame

Before attaching the floorboards I stood on them and noticed some flex when stepping onto the pedicab’s platform. I decided to add a cross support to provide some additional strength and stability to the floor.

ced58193d8b4f5c9eb49d6f9d180d9e4

Hitch attachment

To connect the pedcab to tow bike’s hitch I created a simple coupler using a 1-1/4” EMT 90° elbow. I purchased a pre-bent 90° elbow because I did not have the means to manually bend 1-1/4” EMT tubing. [My pipe bender will bend only 1” EMT.] Also, as you will see later, the OD of 1-1/4” EMT slides nicely into the inside of a 1-1/2” EMT tube. In this way the pedicab is detachable from the hitch — for portability purposes.

ce17f3579430e00637325ce88e191547

Attaching the hitch attachment

I made a couple cuts into the coupler in order to have it slide over the frame and cross support. These two cuts were made long enough to provide enough weld inches for strength. Because the trailer is detachable from the hitch, a 5/16″ pin with a wire lock mechanism was used to secure the coupler type to the hitch tube.

6b1090d9b9dede199ec5f84d64aa5032

The helm joint

Google “pedicab trailer hitch” and you will get thousands of results. I discovered a variety of homemade designs. The one I decided upon is pictured here. The key component of this design is the “spherical” joint, also known as a him joint or rod end bearing. The ball joint is essential for providing movement on X, Y, and Z axes. Trust me on this, the hitch needs to allow the trailer to move left and right (X axis); up and down (Y axis); and to tilt when the tow bike leans in to a turn (Z axis).

 

120dbed39c7a84ee14d25fdeee5a1aa7

Homemade square steel tubing

Seat post sleeve. I fabricated the square tubing by welding together two pieces of angle iron. Make sure the sleeve slides easily over the seat post of the tow bike. A piece of appropriately-sized pipe, EMT, or a bushing can all work for this purpose. I set the seat post sleeve at an angle that matched that of the tow bike’s seat post.

b124955a7207bf12d79c1c56edbc712d

Homemade rod-end bearing

Weld the spherical joint to a bolt. This bolt will be used to connect to the top tube of the of the hitch arm. As noted previously, this ball joint is key to providing X-, Y- and Z-axis movement. My first hitch design allowed for only X- and Y-axis movement. The entire rig was very difficult to turn. Because the tow bike could not be leaned independently of the trailer, the trailer had a tendency to steer the tow bike.

19c072c53a60fa37b53ad0c72686a72a

More hitch fabrication

Creating the end cap of the hitch’s top tube. Weld a steel nut into the center of a steel washer that is at least the size of the OD of your hitch’s top tube. Note: I sanded the corners of the nut slightly in order to have it fit inside the center hole of the washer. Then weld the washer onto the end of the top tube.

6b55067203b902307d6053cba822b008

Putting together the hitch

Putting it all together. I welded flanges to the top and bottom of the seat post sleeve. The spherical joint is slid between these pieces. Holes have drilled in the flanges for the hitch pin to be inserted. Note the use of a nut to lock down the spherical joint bolt to the top tub. Hint: loosen this nut when installing the trailer to the tow bike. Then, when in position, tighten the nut.

c396678e17e08dc613b02ea8222890eb

Floorboards

I discovered a few pieces of pre-finished engineered hardwood flooring sitting in the back of my garage. W00t! Recycle, Reuse, Repurpose. These salvage pieces work great for the pedicab’s floorboards. Pros: strong, durable, and look good. Con: Very heavy. If they didn’t weigh so much, I would have considered using them for the seat bottom and back as well…a la picnic table style.

6c3b5ddc58e1836c4cc0995734f53752

Carriage bolts looks nice

I used carriage bolts to attach the floorboards to the pedicab’s frame. Carriage bolts have a rounded smooth top that are perfectly suited for the pedicab’s floor. Plus they give it a good look. Note, carriage bolts will require a square hole. [Hint: drill a hole and then use a square file to reshape.]

78f646f988bc11ff827c6f632f833387

Beginning the seat

For the seat bottom and back I’m starting with a sheet of ply wood. I will pad and upholster these pieces to make custom seat cushions. Like the floorboards, these plywood sheets are attached to the frame using carriage bolts. Under the seat bottom I welded a cross support to add strength and rigidity to the seat.

88a6b05284524fba8ffb37c1dd107710

Making armrests

Making armrests. The armrests for the seat were made from 1″ EMT. I was able to use my pipe bender on the 1″ size, so no need to buy 90° elbows. These were clamped into place; positioned appropriately and then welded onto the frame.

b57e42ff78fb8da29a67902fcb9a74d8

Preparing to paint

With the pedicab build essentially complete it is now time to add the icing (i.e. paint). Break down the build to its separate components in order to prep for painting; clean up welds; remove weld splatter; sand rough areas; etc. etc. The more pre-painting prep work you do, the better the result of painting. I intend to prime, paint and let cure over the course of a few days. While I’m waiting for the paint to cure, I’ll upholster the seat bottom and back.

ce4abe3ce27f19d1f05827e28700aab8

Top bar

Prior to painting I added a top bar bar to the frame. This piece will ultimately support hooks, lights and other accoutrements.

32f36eb4eb707214127f589f0cc58ea6

Making the seat cushions

Making the seat cushions. I sanded the edges of the plywood seat back and bottom so that they would not tear the fabric. Note: if the plywood fits snugly into the frame, then you may need to trim the size slightly in order for the plywood to be able to fit again after the fabric is attached.

de86f135d538fc1c39a1fd7be5490f46

Upholstering the seat

There is no shortage of how-to videos and online resources that provide instructions on upholstering a bench. [Google “upholster a bench” to see what I mean.] Just remember to cut the fabric large enough to wrap around the foam padding and plywood back while leaving ample fabric to which to staple. You can always trim off the excess later. Also, don’t forget to place your bolts in the seat back prior to upholstering.

ec69a98948f29dab7ac4d424cdd7c248