Tall Front Loader Cargo Bike
The Concept
I wanted to build another cargo bike, this time with an extra large cargo hold. Of course, I couldn't go for something that's been done before, so instead I chose to put my own spin on the Frances Cycles Mixte Haul. It's taller for extra cargo space and weird factor. Using a 240mm dropper allows the rider to still touch the ground at red lights, but elevate themselves above the masses when riding.
Front Half
The nonstandard front cargo area required a custom jig for fitup and welding. I used a mixture of 3D printed blocks, Aluminum extrusion, and aluminum locating bosses on an optical table in order to somewhat accurately locate all of the tubes.
Tube mitering was accomplished via a mixture of hand filing with 3d printed guides and using a hole saw on a mill.
Bottom of the cargo cage tube mitered using a hole saw on the mill
Clocking jig for the front angled tubes on the cargo cage
Partially miter-by-file tube using the 3D print as a guide
Front cargo cage angled tubes with fully fitted compound miters
Rear head tube locating bosses were turned from aluminum on the lathe
All front cargo tubes tack welded in the jig!
The bike was built in two parts for ease of welding, and then welded together at the end. The front part was tacked in the jig, and then removed for full welding. Welding an assembly this large was extremely challenging, and required a ton of out of position welding in tight crevices.
So many joints to weld...
Some late additions to the front cargo area included cargo spars and front plate, as well as some badges for extra style points.
Cargo spar with the welded in nuts
Fusion welds always look so nice...
Spars welded to the cargo area!
Front mounting plate
Silver brazed stainless badge. I felt like a whale is a pretty good mascot for this bike...
Rear Half
Luckily the rear triangle could be built almost entirely in the standard Anvil jig. I started with the seat tube assembly, which included the upper bottom bracket shell, a seat collar, and a brazed in dropper routing tube.
Seat collar butt weld
Slotted seat collar attached to seat tube
3D printed jig for mitering bottom brackets
Seat tube to bottom bracket weld
Full Seat Tube assembly
Silver brazed brass dropper routing tube
I needed some custom rear dropouts to account for my extra large chainstays. I machined these from mild steel on the Haas VF4.
First operation on the drive side dropout.
Drive side and non drive side dropouts after the first operation
Softjaws for holding the drive side second operation
Drive side loaded in soft jaws for second operation
Finished Drive Side!
Finished non drive side!
Fitting up the chainstays to the dropouts and bottom bracket in the Anvil Jig
Mitering the seatstays was extra challenging due to their off angle miters and bend. I ended up bending the stays and then measuring the center of the bend using a bunch of 123 blocks and a little guesswork. This was then used to locate and clock 3D printed miter guides. The tubes were filed to fit, and the seatstays were welded on. The filing method was mostly successful, however the seatstays are not quite perfectly symmetrical to one another. Just adds a little bit more character...
Fully welded rear triangle!
Rear disk brake tab
Both halves on the optical table. Right about here is when I started realizing just how big this thing is...
Two halves are now one!
Originally I had planned to make a fork myself for this bike, but in the interest of time I instead bought the same fork I had used on my mini cargo bike and extended the steerer.
This bike remote steers via a linkage. I machined a set of aluminum clamping linkages, and then welded a tie rod to create the linkage mechanism.
First operation on the linkages
Using softjaws to hold the parts for the second op
Linkages after first and second op
Third(?) Op, adding the clamp bolt hole and slot. I did this part just by hand jogging, no programming required.
The tie rod used two stainless coupling nuts on which I turned a shoulder to fit the ID of a steel tube.
Just enough clearance for the reamer/facer.
Linkage steering system in action.
Chainline is something like a high pivot... but not really :)
Overall, super happy with the way this turned out. It took a VERY long time to go from concept to reality. The result is surprisingly very functional, and not altogether too heavy. The dropper post makes getting on and off a breeze, and the tall factor adds an amazing amount of fun to riding it around. Plus the cargo area is super functional, and more than double that of my previous mini cargo bike.
A full load of bikes back from powder coating!
I also machined a little kickstand mounting plate to lock the rotation of the kickstand. This keeps it from shifting when kicked, which would scratch the paint.