Vintage Japanese Bicycle (Model Types) ①Heavy-duty Cargo Cycle

次回この記事の日本語版を投稿します。

As mentioned in the previous post, Vintage Japanese Bicycle (Model Types), we will begin to look at the six main single gear bicycles in order.
①Heavy-duty Cargo Cycle
②Light-duty Cargo Cycle
③Utility Cycle
④Ladies Cycle
⑤Gents Cycle
⑥Unisex Cycle

Heavy-duty Cargo Cycle
Also known as a heavy-duty cycle, these were human powered trucks on two wheels used to carry large heavy items as well as haul trailers.（←link Japanese only) 
(↓click on photo to enlarge ↓)

Specifications varied depending on the manufacturer and model; however, there are common characteristics.
Let's look at 10 common characteristics.  (↓click on photo to enlarge ↓)

①Extra heavy-duty frame with extra-long wheelbase
Frame designs varied but, since these bicycles would be carrying heavy loads, in order to increase stability many were designed to lower the rider's center of gravity.  Thus, the saddle position is often noticeably lower.  Tubing was thick-walled and some models even had double top tubes, double or reinforced seat tubes and triple frame stays to enhance strength.　

Typical diamond (double-triangle) bicycle frame design.
Note how the saddle is noticeably offset to lower the center of gravity; thereby providing greater stability.



Double top tube design with reinforced seat tube.
Notice the additional top tube and seat tube to provide greater strength for carrying very heavy loads.
Also, notice the foot pegs located at the end of the rear rack stays in the photo below which allowed a passenger to sit on the rack.

X-shaped frame design with triple stays.
Notice the X-shape and triple frame stays, all incorporated to provide greater strength.

②Saddle
The #750 saddle (shown below) was the most common; however, the #1300 was also used.

③Wide flat handlebars

④Extra-large rear rack with four stays

⑤Truss rods (Front fork stabilizers)
Truss rods helped to absorb shock while at the same time stiffen the fork.

⑥Half chaincase

⑦Drivetrain
Crankwheel (Chainwheel): 44 teeth or 48 teeth

Freewheel: 22 teeth
Chain: 116, 118 or 120 links

⑧Roller stand
The roller stand was the most common stand used on heavy-duty cargo cycles; however, the box stand was also used.

⑨Rear wheel
B/E (Beaded Edge) rim, tube and tire: 26" x 2" or 26" x 2" 1/2

#10, #12 or #13 gauge (black enamel) spokes
Heavy duty spindle 7/16" 
Large band brake

⑩Front wheel
B/E (Beaded Edge) rim, tube and tire: 26" x 1" 3/4

#12 or #13 gauge (black enamel) spokes
Rim brake (note the large brake shoes specifically for cargo cycles)

Left: Cargo cycle brake shoe
Right: Normal brake shoe

In the next English post, we will continue our look at the six main single gear models with the next model being the light-weight cargo cycle.