Is the gear cycle a sham? [closed]

Question

Why do I think (and based on my personal observation) that gears in cycles are no better? It just slows down the cycle speed. The effort needed to push the cycle is more in a gear cycle. Considering everything else equal.

Answer 1

If I am understanding the question correctly, the OP is asking what benefit there is to a multi-speed bike compared to a single-speed bike.

The human body acts as a high-torque, low-power engine. Torque is a measure of work. Power is work per unit time. A strong cyclist may have as much torque as a small car engine, but less power than a chainsaw engine.

There's also a narrow range of cadences (pedal speeds) at which we can pedal efficiently—for a trained cyclist, this would be roughly 60–120 rpm—the maximum cadence is only 2× the minimum. Compare that to a car engine that might have a useful power band of 1000–6000 rpm.

In order to use our limited power efficiently and keep our cadence in a useful range, we need to be able to vary our mechanical advantage, which is what gears do.

For me, on a single-speed bike with 42×17 gearing, I'd be traveling at about 19 km/h at a cadence of 60 rpm. But on a 5% grade, I would need to put out about 270 W of power to maintain 19 km/h. I can do that, but it's hard—I can't do it for long. To get my speed down to a power level I can comfortably sustain, my cadence would need to be about 35 rpm—uncomfortably slow.

Conversely, when riding with a tailwind or down a hill, bigger gears let you ride faster than your maximum cadence would otherwise allow.

You can play around with power calculations here, and gearing calculations here.

Answer 2

I think the question is asking if derailleurs and multiple cogs/chainrings are not worth the cost and complexity compared to fixed gear or single-speed bikes.

Track cycling only uses fixed gear bikes. There are some substantive reasons for this, in addition to tradition. Fixed gear bikes (fixies) or single-speed bikes were once fashionable for some casual cyclists in urban environments. They seem to have declined in popularity in the US for now, but they might yet come back. Single-speed has niches in some MTB and cyclocross races.

In general, if derailleur bikes were not a cost-effective improvement over single-speed bikes, you would expect the technology would not have been adopted. Indeed, Henri Desgranges would have preferred the entire world to remain single-speed (or more likely with two cogs on a flippable rear hub):

... I still feel that variable gears are only for people over 45. Isn’t it better to triumph by the strength of your muscles than by the artifice of a derailleur? We are getting soft. Come on fellows. Let’s say that the test was a fine demonstration – for our grandparents! As for me, give me a fixed gear!”

• Desgranges interview with L'Equipe, translated, date uncertain. Test refers to a test of a 3s derailleur bike vs a fixie.

The fact is that derailleurs let average users traverse a wider range of terrain. Even relatively fit amateurs have benefitted from the increase in range as we hit 11s drivetrains.

There is a learning curve with derailleurs. That is, you have to learn things like downshifting (easier gear) before you come to a stop, how to choose a gear for your terrain, how to use the front derailleur if you have one, cable maintenance, etc. If you feel that your derailleur performs poorly, you can perform some basic adjustments to the cable tension or the travel limits. Or the cable and housing may need replacement. If you have well-maintained derailleurs, cables, and housing, most cyclists will feel that the setup is better than a fixie or single-speed. In particular, it sounds like the OP might have not been in the right gear - if you are starting from a stop, you want to be in an easier gear, and you have to shift before you stop.