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Brand: MEROCA
Model: RAO
Colour: Black
BCD: 104mm
Tooth pattern: BC1.37-24T
Material: 6061 aluminum alloy
Length: 170mm
Bottom bracket: threaded BB68/73mm
weight:
Crank about 700g
Bottom bracket about 100g
32T chain ring about 41g
34T chain ring about 52g
36T chain ring about 62g
38T chain ring about 81g


Crank The includes: left and right cranks + fixing screws (4 Pcs) + gifts (1 pair of crank silicone protective sleeves in red)
Crankset The includes: left and right cranks + chain rings + fixing screws (4 Pcs) +BB(68/73mm)+ gifts (1 pair of crank silicone protective sleeves in red)
Features:
1. High-strength aluminum alloy material, CNC forged, improves strength and reduces weight. The weight of the left and right cranks is about 700g.
2. Compatible with 8/9/10/11/12 speeds, the chain ring adopts a narrow and wide tooth shape design, and the chain will not fall off.
3. 104/64BCD is compatible with 1x 2x 3x speed.
4. If the bottom bracket of your frame is threaded and the width is 68-73mm, it can be used with your bicycle.

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Early Years (1817-1839)

• The first known prototype of a bicycle-like vehicle was invented by German inventor Karl von Drais in 1817. It had no pedals and was propelled by the rider's feet pushing against the ground.
• In the 1830s, French inventor Kirkpatrick MacMillan developed the first pedal-powered bicycle, which was made of wood and iron.

The "Penny Farthing" Era (1870s-1880s)

• In the late 19th century, the "penny farthing" bicycle became popular, characterized by its large front wheel and small rear wheel.
• This design was problematic, as it was prone to tipping over and was difficult to ride.

The "Safety Bicycle" Era (1880s-1890s)

• In the 1880s, John Kemp Starley, an English inventor, developed the "safety bicycle," which featured a chain-driven mechanism, pneumatic tires, and equal-sized wheels.
• This design became the standard for modern bicycles and remains largely unchanged today.

The "Golden Age" of Bicycles (1890s-1920s)

• During this period, bicycles became more accessible and affordable for the general public.
• The development of steel tubing allowed for lighter, stronger frames, and the introduction of derailleur gears made riding easier and more efficient.

Post-War Innovations (1940s-1980s)

• After World War II, bicycles became more popular as a means of transportation and recreation.
• Innovations such as the introduction of derailleur gears, disc brakes, and improved suspension systems made riding more comfortable and enjoyable.

Modern Era (1990s-Present)

• The rise of mountain biking in the 1990s led to the development of specialized frames, forks, and suspension systems.
• Advances in materials science have led to the creation of lighter, stronger, and more durable frames.
• Electric bicycles (e-bikes) have also become popular in recent years.

Of course, this is just a brief overview, and there are many more fascinating stories and innovations within the history of bicycles.