Rotor INPower 3D+ Review


Ease of Installation

Value for Money

Ease of Battery Change

Power Phase Analysis ​

Where To Get It

A Deep Dive Into ​Rotor INPower 3D+

​The Rotor INPower 3D+ power meter has been reviewed by Tristan Haskins for Rotor are a well established Spanish brand behind Q-Rings. An innovative chainring design that generate a more continuous power curve.

Producing a product that improves pedal efficiency lead Rotor to design and manufacture their INPower Power Meters.

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  • Who is it For?


  • ​Who is it NOT for?


  • Pros & Cons


If you already train with Q-Rings then it makes sense to use a power metering system developed by the company who made your chainring. This product is for the customer who currently rides with Q-Rings and Rotor crank arms seeking to add power metering by REPLACING the left side crank arm with this new one.

All the INPower products have been optimized for Q-Rings with the unique TORQUE 360 and OCA (Optimum Chainring Angle) features. Torque 360 and OCA help cyclists precisely and accurately analyze force variations in their pedal stroke (if supported by head unit). If you’re interested in the shape of your power curve and want to know if you’re achieving the perfect power peanut this could be the power meter for you.

​This power meter is NOT compatible with a Shimano, FSA or Campagnolo equipped drivetrain. It is intended to replace an EXISTING Rotor (non-power) left-side crank arm and axle. If you have Shimano, FSA or Campagnolo and do not want to switch to Rotor please consider something else, eg single sided power metering pedal like Vector 2S or PowerTap P1S or a simple left side only crank arm eg. 4iiii Precision.


  • All electronics housed inside spindle, safe from the elements
  • Accurate power metering with Rotor Q-Rings
  • Up to 300 hours battery life from a regular AA battery
  • 10 second battery change, no tools required
  • Provides 360 Power Phase Analysis via software
  • Broadcasts in both ANT+ and Bluetooth 4.0 (BTLE smart)
  • 100% CNC-machined, 7055 aluminum alloy


  • May require local bike shop fitting … but well worth £50/$60 fitting charge

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More Rotor Products

Rotor have designed their power meters for all cycling styles and disciplines. As such they have the INPower REX dedicated for MTB as well as their aerodynamic FLOW MAS (micro adjust spider) system for road racing and triathlon. Wiggle have the wide range of Rotor INPower power meters

Method of Installation

How hard is it to fit the INPower 3D left side power meter? That depends on your bike mechanic skills. Assuming you already have a Rotor (non-power) crankset installed it shouldn’t be too hard. If you’re running something else like Shimano, Campagnolo or FSA then STOP … this product MUST be fitted to a Rotor crankset system.

The drive side chainring and crank needs removing first. In the video section below the team at GCN show precisely how to do this in a very short video. Once the old left side crank has been separated from the drivetrain side the new power metering LEFT side crank arm and axle can be fitted in place of the original non-power variant.

In all honesty, as with all power meters with exception of pedals and crank arms, installing the INPower 3D is beyond my comfort zone / skill set. I’d look to my local bike shop for installation.

Tools Required to fit this Power Meter

  • 8mm allen key
  • A torque wrench with an 8mm fitting,
  • A Shimano cassette locking removal tool
  • Plastic mallet

Alternative Power Meters

These Rotor INPower power meters are quite unique measuring the power from the axle and NOT within the crank arm shaft. There are no direct alternatives that work in the same way as these axle power meters. If you have a Rotor crankset and want to add power metering then stick with this INPower system.

For those seeking a simple left side power measurement system wanting to keep their existing crankset, chainset etc. the simplest solution are the crank arm power meters from 4iiii, Precision and Pioneer.

​Technical Specification

  • Power metrics are easily sent to your ANT+ device (head unit) so you can see your results
  • Integrated electronics (and battery) housed within the axle making for cleaner data transfer
  • INpower uses a standard AA battery that typically lasts 300 hours when fully charged
  • INpower cranks use UBB (universal bottom bracket) and are compatible with almost every bike frame on the market
  • INpower software features different modules to optimise your cycling performance
  • INpower is compatible with all Rotor 30mm cranks
  • Weight: Approx. 325g
  • Strain gauges: 4
  • Battery: AA 1.5V (300 hours riding time)
  • Water resistance: IPX7
  • Wireless technology: ANT+ 2.4Ghz
  • Data transmitted: Power, Cadence, TORQUE 360, OCA, torque effectiveness (left) and pedal smoothness (left)
  • Analysis software: Trainingpeaks/ROTOR
  • Software: ROTOR INpower user software

​Photo Gallery

External Videos

1) Removing / Changing Rotor Cranks (GCN)

Rotor cranks are removed and changed in a very different fashion from Shimano cranks. This video we show you how to remove Rotor cranks. To fit the INPower power meter crank simply exhange the NEW crank arm for the original LEFT side no
n-power crank once seperated from the drivetrain.

2) Installing the Rotor Cranks

3) INPower Software for 360 degree power analysis

INpower features TORQUE 360 and Optimum Chainring Angle (OCA) pedal analysis, which help cyclists precisely and accurately assess force variations in their pedal stroke. TORQUE 360 and OCA values enable cyclists to orient their Q-Rings around their distinct pedaling characteristics in order to take advantage of their most productive zone. This short video shows the INPower software analysing the power phase of a rider.

External Resources

The purpose of product presentations is to give the visitor a summary overview of each power meter. They are NOT intended as an in-depth technical review, more a summary providing essential top level features, functions, pros and cons. Further information can be found at these links to other external reference sites.

Product Summary

A sophisticated power metering system with all the sensitive electronics housed inside the axle unit. The Rotor INPower 3D extracts power from the left leg only to give an estimated TOTAL power by doubling precise power from the left side. Fans of this power meter are attracted to it’s robust design and the 300 hour battery life from a single AA battery.

This model comes as LEFT crank only. For the complete crankset with both LEFT and RIGHT crank arms please consider the Rotor INPower 3D DOUBLE (note, it still only measures POWER from the LEFT leg)

INPower 3D30 versus 3D+? Rotor also produce an INPower 3D30 power meter product. The key difference between the 3D30 and this one is the 3D+ is 100% manufactured by an aluminum / CNC milling process making it 2-g lighter than the 3D30 left side power meter crank.

Read Other Review: Powertap C1 Chainring Review

Andrew Wyatt

Andrew Wyatt

Andrew Wyatt from Texas has been the best-selling author in 2014. He was the most appreciated writer in 2015. Different organizations have honored him with different awards and memberships as well. He is a tech shop owner and completed graduation in Electrical Engineering.

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