My Swing Arm DIY 2-Bike Carrier

Here's a bit of a write up of my bike carrier that I attach to my swing arm when I carry more than 1 bike.


Backstory:

My adventure Tacoma is designed to carry me and my Surly fat bike to fun explorations. Inside the Super Pacific X1 all the elements are designed around carrying my bike inside – out of the elements and greater, secure, piece of mind. This has been a perfect design.

On occasion I have transported an additional bike, or two. The extra bikes have required some tetris-like skills to get them tied down or put an additional bike inside. So, I came to the conclusion that I would love to have a way to more easily carry additional bikes, but not be overly complex nor spendy.

Note: The weight of the carrier, with all its trimmings, is 24lbs.

The Base Criteria

• Must be compatible with my swing arm – bikes must clear my 11lb propane tank.
• Should not make access to the camper more difficult nor awkward.
• Try to use any existing materials, if they are sufficient to keep costs low-ish.

What I Ruled Out

• Vertical carriers – would lose too much ground and/or height clearance.
• Roof-top carriers – too high, too difficult to get bikes up there.

Research
I looked at what was available commercially.

• Quite expensive for something that would see low, occasional use.
• Many hitch-mounted do not have enough extension to clear my swing arm items.
• Additional hitch mount racks would add another item to swing open to gain access to the back of the camper/truck.

My Solution
I decided that, for me, the ideal approach would be to build something myself. The carrier will attach directly to the swing arm, so accessing the camper would be no different than before.

Materials:

• 2 1-1/4” hitch receivers – to attach to bottom of swing arm
• 2 1-1/4” square tubing, 1/8” wall
• 2 Yakima round bars, 60” long
• 2 wheel trays – modified to accept 5” tire width
• 4 anti-vibration clamps 1-1/8” diameter
• Salvaged pieces from some Yakima trays
• 2, SS wire-lock clevis pins
• ½” diameter, 0.058” wall thickness tubing
• 2 tube-end weld nut, 5/16”-24 thread
• 5/16”-24 SS threaded rod
• Inline ball joint, 5/16”-24 thread
• Ball joint rod end, 7/16”-20
• A few hardware odds and ends

Fabrications
This carrier consisted of some new fabrication and modifying some existing elements to fit my criteria.

Base Support Arms
At the heart of this build are the square tubing that will be held to the swing arm by the hitch receivers. To start, I reached out to an online friend/fabricator to weld the hitch receivers to my swing arm. I figured MIG welding would be less destructive to my powder coat than if I attempted to gas weld myself. I determined where to locate the receivers, then ground the area in preparation for welding.



For the tubing, I wanted to cap the ends and drill to be able to pin the tubing into the receivers. To cap, I cut 3 sides off, then bent over the 4th side and welded. After drilling the pin holes, I then measured the location for the first bike, ensuring I had clearance for my propane tank. The Yakima round bars are held securely using vibration-damping, routing clamps (1-1/8” diameter, McMaster #11355T68). Attaching the clamps to the tubing, I drilled, counterbored holes to accept M6 threaded rivet-nuts. The counterbored holes place the top shoulder of the rivet-nuts flush with the top of the tubing.



The second bike placement is set at 10” center-to-center. With the round bar locations set, I then cut and capped the tubing ends.



Front Wheel Trays
Way back, when I owned a sub-compact car, I did some searching for a way to tote my fat bike on the roof top. I had ordered some wheel trays that were listed as fat bike, but were too narrow. Fast forward and I still had these trays and decided a bit of altering would make these work for my project.

I removed the bottom extensions to create a flat mounting surface. I then used heat and a couple of 4” PVC joiners to expand the tray width from 3” to just under 5”. After forming the wheel trays, I then fabricated the brackets that will adapt the trays to the Yakima round bars using the standard click-around clamps.





Rear Wheel Chocks
For the rear wheel I used sections of Yakima wheel trays that I flattened out some. One tray is used as a support to ease rear wheel locating. The other tray is used as an adjustable “chock” and aids in preventing fore-aft movement of the bike.

I am using Voile straps to secure front and rear wheels to the carrier.



Stabilizers
To keep the bikes vertical, I use 2 stabilizers – swing arm to bike 1, and bike 1 to bike 2. I do use a “security blanket” strap that runs from swing arm to bike 2. After a couple of prototype designs, I arrived at my final stabilizer solution.



Stabilizer 1 consists of:

• Bracket attached to the swing arm.
• Ball joint rod end that fits into the swing arm bracket, held with an adjustable clevis pin. (I have since replaced the clevis pin with a 3/8” bolt and nut to better pinch the brass sleeves against the inner ring of the ball joint. This eliminates looseness.)
• .500” round tube, tapped on one end to accept the ball joint, the other end has a threaded bung welded in.
• 5/16”-24 threaded rod that allows for length adjustments.
• Thumb wheel to lock the length adjustment.
• Inline ball joint to adapt to various top tube angles.
• Rubber-lined piece of track to securely attach to the top tube.

Stabilizer 2 consists of:

• Two rubber-lined pieces of track – connects the 2 bikes together.
• Round tube, 5/16” -24 threaded rod brazed to one end.
• 5/16”-24 internal threaded bung welded to other end.
• 5/16”-24 threaded rod.
• Thumb wheel to lock the length adjustment.

Here's the one stabilizer attached to swing arm and bike. The inline ball joint allows for slight tilt angle adjustments.


For near-home day rides, this has worked very well, easy on and easy off.

Thanks for reading.

 

Nice! Does the attatchment to the frame not scratch it? Also, where is the swing out?

 

Hey, thanks.

No scratching. The clamp is rubber lined.

The swing arm opened (note: this was an earlier version with my prototype stabilizer):