Interbike 2010: SRM offer power meters for compact cranks

Plus PowerControl 7 computer and Mac compatibility

Matt Pacocha

Published: September 28, 2010 at 9:20 am

SRM have been making cycling power meters for 25 years, and they offer models to suit a wide variety of standard road cranksets. However, until now, if you wanted to use an SRM meter with compact cranks the only option was FSA.

In recent years, more and more sponsored riders have been asking the company for 110bcd models and then riding them under the public radar. Daniel Gillespie, SRM’s team liaison, says Liquigas, Garmin, Saxo Bank and RadioShack all had 10 or more compact cranks on the team trucks in 2010.

For 2011, SRM are responding to demand and adding Cannondale Hollowgram SI, SRAM S975 (GXP and BB30), Shimano Dura-Ace 7800 and Specialized S-Works compact options, alongside the existing FSA K-Force Light and Gossamer models. All will also be offered in standard configurations, and SRM will also offer two new models incorporated into Spanish company Rotor’s cranks.

A rotor crank arm option will be available late spring 2011.: a rotor crank arm option will be available late spring 2011. - Matt Pacocha

SRM power meters will be offered with Rotor crankarms and rings in 2011

Though still in prototype form, SRM are planning to offer a Shimano Dura-Ace 7900 compatible compact unit in 2011, too. The standard 7900 version costs $3,045 and weighs 820g. The main benefits of the new compact version over the 7800 equivalent are the 7900 chainrings and compatible spider, which are said to bolster stiffness by 20 percent. The crank arms will remain the same.

SRM's shimano 7900 compatible standard 130bcd crank: - Matt Pacocha

The 7900 compatible unit will offer a claimed 20 percent increase in chainring rigidity, but still sport 7800 crank arms

In addition to the new road models, SRM will offer 2x10 compatible mountain bike models with FSA K-Force ($2,299, 757g) and Cannondale Hollowgram SI ($1,799, 521g w/o BB spindle) arms from early 2011. A SRAM branded 2x10 model should be available in time for the Sea Otter Classic in April. The mountain models use SRAM/Truvativ’s 120mm/80mm X-Glide bolt circle diameter.

FSA's k-force 2x10 mountain crank with sram x-glide bcd: fsa's k-force 2x10 mountain crank with sram x-glide bcd - Matt Pacocha

SRM's FSA K-Force mountain bike crank with Truvativ X-Glide rings

Power Control 7

SRM's latest PowerControl 7 computer offers real-time data display and capture wirelessly via the ANT and ANT protocols. It's smaller than its PC 6 predecessor (18mm narrower and 18g lighter) and offers additional mounts for time trial bars.

The computer is housed in a new shock resistant plastic and is said to be the most durable unit SRM have ever produced. “SRM components are built for the best racers and the worst conditions,” said Mike Hall, while presenting for SRM at SRAM’s Interbike Power Seminar.

Colour options for the 2011 powercontrol 7: - Matt Pacocha

A dozen colour options are available for the PowerControl 7 computer in 2011

Possilbly the biggest improvements to the computer are its batteries, which can hold their charge for 130 hours, and its memory capacity – over 120 hours at a one second capture rate. According to SRM, the unit is built to last an entire grand tour on one charge and without the need to download data to free up memory space.

PC 7 offers data fields for power, cadence, speed, heartrate, energy, training zones, intervals, temperature, altitude, ride time and a time-of-day clock; each field offers three choices for viewing: real time, average and maximum. It's available in 12 colours, weighs 58g and costs $950.

Straight Mac compatibility for 2011

The final arrow in SRM’s 2011 quiver is their SRM Evaluation Mac V1.0 software which allows users to access training files from the PowerControl 6 and 7 units. The new software works in the native Mac OS environment, ending the need for virtual PC software.

The software offers control over all of the options on the PowerControl computer units. Users can read and write SRMWin compatible files as well as carry out basic graphical analysis. The system functions with Mac OS X 10.5 and newer operating systems. It'll be available as a free download on SRM’s website in November.