Rearward sensors for road bikes are important accessories that increase safety when cycling. The following is a summary of their advantages and disadvantages and a comparison of specifications of major products.
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Shimano Power Meter Features
Crank Type Power Meter
Currently, the mainstream power meters are pedal type and crank type, but Shimano’s power meters are crank type. DURA-ACE and ULTEGRA grade cranks for road bikes are lined up with models equipped with power meters (with “P” at the end of the model number).
Shimano’s power meters first appeared surprisingly recently in 2016 and started to be distributed in Japan in 2017, with the then latest R9100 series of the top-of-the-line DURA-ACE grade road bikes.
It was then upgraded to the latest DURA-ACE R9200 series released in 2021, and with the simultaneous release of the ULTEGRA R8100 series, the first cranks with a power meter were added to the ULTEGRA lineup.
Shimano Power Meter Lineup
The latest DURA-ACE crank with power meter, just released in 2021. Power measurement is by dual sensors on the left and right sides, and power accuracy has been improved from the previous model, FC-R9100, to ±1.5%. As with the previous model, the built-in battery system allows up to 300 hours of continuous operation.
The unified design is also a good feature if it is a genuine Shimano product.
The FC-R8100-P is ULTEGRA’s first crank equipped with a power meter, as the previous series, the R8000 series, did not have a model equipped with a power meter.
Power accuracy is ±2.0%. It is slightly lower than the higher grade FC-R9200-P, but it is the same in that it has dual sensors on both legs and a built-in battery system for up to 300 hours of continuous operation.
In terms of power meter specifications, it is similar to DURA-ACE’s previous model FC-R9100-P.
Shimano’s first power meter crank was the FC-R9100-P. With dual sensors capable of measuring both legs and a built-in battery for 300 hours of continuous operation, the FC-R9100-P was a revolutionary spec at the time of its release and is still a viable power meter today.
However, in terms of power meter performance, it is equivalent to the FC-R8100-P, which will be released in 2021, so the FC-R8100-P should be considered for future support.
Differences between Shimano’s Power Meters
First, let’s look at the differences between Shimano’s power meters.
|Year of release||2021年||2021年||2017年|
|Power||Built-in Battery||Built-in Battery||Built-in Battery|
|Battery life||more than 300 hours||more than 300 hours|
The major differences are power accuracy and crank length: the FC-R9200-P has a higher power system, while the older model, FC-R9100-P, does not have a 165 mm crank lineup.
Other than that, all models are generally the same, but the older model, FC-R9100-P, weighs about 60g less.
This will be important for those who are concerned with weight reduction.
How to choose a Shimano power meter
Shimano’s power meter is exactly the same as the company’s Hollowtech II crank, a model with a power meter on it, and the performance is almost the same side by side, so choosing a power meter is based on the crank. In terms of price, the Power Meter model is based on the same type of crank, plus 90,000-100,000.
For hobby use, it would be cosmetic to look for an ULTEGRA FC-R8100-P or a used FC-R9100-P.
Serious users with DURA-ACE components would want to use the FC-R9200-P, but considering that the price is almost 180,000, it may be more cost-effective to use another pedal-powered power meter.