The advantages and disadvantages of the 10-tooth first sprocket
The efficiency of a drivetrain with smaller sprockets is often challenged due to the increased friction between the chain and the sprocket itself, and the more rotation required of each link in the chain.
It is important to clarify that this concern mainly concerns the efficiency of the transmission when every other component of the system is identical. However, in actual comparisons between two groupsets with different sprockets, it is essential to consider any differences in components, such as the chain, the number of teeth on the derailleur pulley, the shape and thickness of the sprocket teeth, and the construction of the chainring.
To get an accurate comparison, consider evaluating the sprockets on an identical 12-speed drivetrain. Additionally, SRAM testing has shown that the efficiency variation between 11 and 10-tooth sprockets is 1%, while between 12- and 11-tooth sprockets is 0.87%. These numbers are extremely small and practically theoretical outside the laboratory, as on the road other factors have a greater influence on the efficiency of the transmission, such as lubrication and cleanliness of the chain.
Another element to consider is the speed at which the 10-tooth sprocket is used. At these high speeds, drag makes up the majority of the total drag, while the efficiency differences between the sprockets are insignificant in practical terms. Also, few riders use the smaller sprocket for extended periods, making the advantage of the 11-tooth less relevant.
However, there are advantages to using smaller sprockets, such as the ability to use smaller chainrings to achieve the same top speed and a reduction in front shifting required. This allows for a smoother ride and less disruption to your rhythm while pedaling.
In conclusion, while the efficiency between 11 and 10 tooth sprockets can be a topic of discussion, all the variables involved and the practical use of the bicycle must be carefully considered. Innovation and technological evolution lead to specific developments for different needs, and 10-tooth sprockets have demonstrated significant advantages for some professional level cyclists.