Put 3 speed gear on push bike.
Notes
Bicycle Gears
Grandad noted that he put three speed gears onto his bicycle which he referred to as a “push bike“. This term is apparently a standard British English expression that emerged around the turn of the 20th century. It distinguished pedal-driven bicycles from motorbikes. This was relevant to grandad as he also owned a motorbike at that time, see Chapter 18. I am familiar with the term although it seems somewhat dated now.
Internal Hub Gear System
At that time, bicycle gears took the form of an internal hub gear system. While these are still included on some specialist city or e-bikes, they have largely been replaced by modern, external derailleur systems.
An internal gear hub relies on a “planetary” gear system hidden entirely inside a sealed metal casing. Inside the hub shell, smaller “planet” gears revolve around a central, locked “sun” gear, allowing the rider to shift between a low gear for climbing hills, a direct 1:1 gear for cruising, and a high gear for flat-out speed. Gears are operated via a handlebar-mounted lever which pulls a tiny indicator chain via a braided cable, shifting an internal sliding clutch to engage different gear ratios.
Advantages and Disadvantages
The main advantages of these systems were their resilience and the fact that gears could be changed while stationary. These advantages explain why some bikes still use that system. However, the modern derailleur system has many advantages including lighter weight; greater efficiency; wider gear range; easier maintenance; simple wheel removal and lower production cost. Because of these many advantages, external derailleur systems are now standard on almost all but the most specialised bikes.
Fitting Gears Was a Major Task
While fitting an internal hub gear system was a major task, it was something that was well within grandad’s capabilities and would have been something he enjoyed doing. It involved completely stripping down the rear half of the bike, removing the tire, and unlacing around 36 to 40 individual spokes to remove the old single-speed hub. Because a three-speed hub is wider and has larger metal flanges, it requires shorter steel spokes. Fitting these was a complex task. There would then have been need for final adjustments including widening the bike’s rigid steel frame arms to accept the wider axle; clamping manual routing clips and a shifter lever to the frame tubes; and micro-adjusting the internal cable tension to prevent the gears from slipping under the rider’s body weight. It would have taken several hours of work to complete the task.
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