Teardown: ROTOR 2InPower Crankset 30mm

Posted on 6 Comments
Rotor 30mm crankset

Introduction

One viewer of the Hambini YouTube channel sent in a bike for service and a new bottom bracket. This bike was fitted with a Rotor power meter crankset. In the process of making a new BB for this bike, the rotor crankset was measured and checked. This post covers the engineering and a general opinion of the construction. If you want a review of the Power meter accuracy, this will not be covered in this guide.

A hot topic in many internet forums is which power meter to get. This situation is muddied because of the varying axle and bottom bracket combinations that exist.

Rotor 30mm crankset
Rotor 30mm Drive Side

Introduction: Rotor Bicycle Components

Rotor are a Spanish company that have long been associated with cranksets and more recently entire goupsets. Their offerings have not always gone well. Their UNO groupset came out when there was a paradigm shift from mechanical to electronic and finally wireless shifting. It was left languishing and very few have been spotted out in the field.

Mechanical Overview

Mechanically, this crankset represents a complete overhaul of the Rotor crankset system. Large elements have been copied from Shimano’s Hollowtech 2 system. Here are some of the mechanical bits in brief:

  1. 30mm Aluminum axle
  2. 90-92mm DBCA (Distance Between Crank Arms)
  3. Axial preload adjuster integrated into the non drive side crank arm.
  4. Single pinch bolt system for the non drive side crank arm
  5. Lightened aluminum alloy crank arms
  6. Accepts standard 130BCD rings and Q Rings
  7. This particular unit has an integrated power meter

This crankset is a different animal. From the outset it is well engineered

Geometrical Checks

Geometrical checks were carried out to establish the true quality of the manufacturing. The axle appears to be pre-machined before a final grinding process on the bearing landings.

The diagram below is an approximation of the measurements taken. A is the datum, P and Q are measures of roundness and indicate the bearing landings. X and Y are run outs and they indicate the amount of bend, strictly speaking the runout at X is the same as the out of roundness of P

Rotor 2InPower Geometrical Checks
Crankset Geometrical Checks Rotor 2InPower

For all practical purposes, the runouts and deviation were less than 0.01mm which can be considered to be zero and thus very good.

Improved Preloading system

A common theme across bike cranksets is poor preloading systems. The displacement type preloading systems such as those used by Shimano are the best. Wave washers are effective but adequate knowledge and use of shimming is required to obtain the best performance. This is often beyond the scope of expertise of most amateur mechanics and even some bike shops.

This rotor crankset has a preload system which is a larger version of that found on the Shimano Hollowtech cranks. A preload bolt on the end of the non drive side crank moves the crank arm in and out and provides displacement level preload adjustment. This is easy to use and mechanically effective.

Installation into a Cervelo Frame with a Hambini Bottom Bracket

This crankset was installed into a Cervelo bike frame with a Hambini Bottom bracket. The final fit and finish were very good. No shimming of the crankset was required

Conclusion

This is a well engineered product. Rotor have really made some vast improvements, the quality of the machining and geometrical accuracy are amongst the best out there. If you are in the market for a 30mm crankset, then this is recommended.

6 thoughts on “Teardown: ROTOR 2InPower Crankset 30mm

  1. Phew. I have two of these and when I see something show up on Hambini I brace for the inevitable news that I’ve bought something with great marketing and poor engineering!

    1. You have to give credit where it is due. This is a well engineered product

  2. Any thoughts on this catastrophic failure of an Aldhu 24? Includes pics.

    https://weightweenies.starbike.com/forum/viewtopic.php?f=3&t=151121&hilit=rotor+aldhu&start=75#p1668424

    Next but one post after that is also a bit concerning.

    Both relate to the steel 24mm system as opposed to their newer 30mm alu system as reviewed here.

    1. It looks like the drive non drive side bearing has been misaligned and fatigued the axle from the photographs. There are running tracks on that side.

  3. Reassuring to see…

    I have an older Rotor 3D24 which I got via P2M with a power meter spider several years ago – it’s fitted on a 2014 Cannondale Supersix hi-mod (one of the older CPC frames that got through the Hambini roast without too much of a kicking).

    I use an outboard bearing BB86 because it originally had a Shimano 6800 crank (BB30/PF30 narrow span also makes no sense to me).

    The rotor crank seemed nicely machined, particularly the idea of machining the NDS arm in it’s closed position then spreading it to fit the spindle.

    The bearing diameters seemed to be ok (not sure about axial alignment, concentric between sides or circularity etc as I only had calipers and buttered fingers to measure it with); plus I like the pre-loading method that’s similar to shimano as it’s easy to fine tune.

    Worth putting a dab of medium duty thread-lock on the alu. pre-load cap (Loctite 248 or similar); mine bounced out one day and it was a cock on + expense getting another from Rotor.

  4. […] whilst the industry typically quotes 2mm. 2mm is a range that the current crop of cranksets from Rotor, Shimano and SRAM can comfortably deal […]

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