The weight weenie spirit is alive and well

By Simon von Bromley

Published: Tuesday, 20 June 2023 at 12:00 am

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Rotor has announced the 2INpower SL, a “superlight” version of its existing dual-sided crank-based power meter.

The Rotor 2INpower SL is built around a CNC-machined aluminium crankset, and weighs a claimed 530g in a 170mm length.

The 2INpower SL crankset can be paired with 1x or 2x direct-mount chainrings, or a 110mm x 4 BCD (Bolt Circle Diameter) chainring spider for use with standard chainrings.

The 2INpower SL power meter has a claimed accuracy rating of +/- 1.5 per cent, and is priced at £860/€999/$1,099 – £110/€50/$56 cheaper than the previous version.

Rotor says it offers a “best in class” option for dedicated cyclists, or for those who wish to improve their pedalling symmetry and efficiency.

The lightest dual-sided power meter

Rotor has produced a number of INpower cranksets in recent years, including single-sided options and an MTB-specific dual-sided version, the Rotor 2INpower MTB.

At a claimed 530g for a 170mm crankset, the new 2INpower SL appears to save 66g versus the existing 2INpower DM Road (claimed weight 596g), the standard dual-sided version for road and gravel bikes.

Rotor says this represents a 15 per cent weight saving (although by our calculations it’s more like 11 per cent).

Rotor

This weight accounts for each crank arm and the integrated 30mm aluminium axle.

With Rotor’s own 50/34t chainrings, the total system weight rises to a claimed 729g.

In comparison, a Shimano Dura-Ace Di2 R9200 power meter crankset (172.5mm cranks, with 52/36t chainrings) weighs 750g.

Independent left/right measurement

Rotor

As with other dual-sided power meter cranksets and pedal systems, such as the Stages LR, Verve InfoCrank Classic or Favero Assioma Duo, the Rotor 2INpower SL offers true (as opposed to estimated) left/right power measurement.

This is because each crank arm or pedal can measure the power produced by each leg independently.

Rotor

In contrast, spider-based power meters, such as the Quarq DFour DUB, Power2Max NG Road or Rotor’s own INspider, measure power between the chainrings and the cranks.

This means that while they measure total power (i.e. that produced by both legs), they can only provide an estimated left/right-leg split.

Though the usefulness of such data to the average rider is still contested by some, if you do want an accurate left/right split then a dual-sided power meter is the way to go.

Rotor

Rotor says its Rotor Power app (available for iOS and Android smart devices) can be used for in-depth pedalling analysis and to optimise the rotation of its Q-rings.

Q-rings are the Spanish brand’s ovalised chainrings, which are claimed to improve pedalling efficiency.

Rotor 2INpower SL pricing, details and specification

Rotor

The Rotor 2INpower SL power meter crankset costs £860/€999/$1,099 and is available in four crank lengths: 165mm, 170mm, 172.5mm and 175mm.

Despite the prices of many bikes and components rocketing in recent years, that’s cheaper than the standard version, which costs £970/€1,049/$1,155.

Perhaps our prediction that prices will fall in 2023 might be coming true after all?

Rotor

The crank arms are made from black anodised, CNC-machined aluminium. It uses a 30mm axle that can be adapted to most bikes using Rotor’s range of bottom brackets.

Rotor says the 2INpower SL uses active temperature compensation, enabling it to remain accurate in temperatures ranging from -20°C to 50°C.

Rotor

As with previous versions, cadence is measured using accelerometers, meaning no frame magnets are required.

The Rotor 2INpower SL can also broadcast advanced power meter metrics such as torque effectiveness and pedal smoothness, via ANT+ and Bluetooth, to compatible bike computers.

It uses a rechargeable Li-ion battery and has a claimed battery life of 250 hours. Rotor also claims the 2INpower SL can be fully recharged in just three hours.

Rotor 2INpower SL specification

• Price: £860/€999/$1,099
• Power meter type: Dual-sided crankset
• Available crank lengths: 165mm, 170mm, 172.5mm and 175mm
• Claimed weight: 530g (170mm cranks)
• Claimed accuracy: +/-1.5 per cent
• Battery type: Rechargeable Li-ion
• Claimed battery life: 250 hours
• Waterproof rating: IP67
• Connectivity: ANT+ and Bluetooth

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