SRM Power Meter with accessories

Above are all of the parts that I am selling with my SRM device.  This device fits on any bike with a BB30 bottom bracket.  All of the devices data signaling and receiving devices are wireless.  I forgot to add the spoke sensor magnet (no biggie, I'll send that with the device when I mail it to the new owner).   The red items are the threaded bolts that attack the crank arms to the spindle (the spindle is not included, but I have two that I can sell if requested.  They are available on ebay or your local bike shop).  The top right black item is the cadence magnet.  It is required for the SRM to turn on when pedaling.  It's super easy to install.  It goes under the cable guides located under the bottom bracket..  The other black item just below the cadence magnet is the handlebar mount for the SRM control.   It is notable that I am including a Cyclops heartrate strap instead of the Suunto heartrate strap.  This is because the The Cyclops device works much better.  Because it's a "wireless ANT + sport" device it is easily synced with the powercontrol device. 

Above is my receipt for the standard annual battery replacement and calibration (or every 700 hours of use).  I didn't expect it to cost so much, but I also didn't expect them to install new firmware, so that's a bonus. 

Keep in mind that this is professional and even scientific grade equipment.  It's pretty advanced and accurate stuff.  It's the best you can buy....... well you can buy a new one for a little over 3 grand (SRM sells their device for 3 grand without the chain rings and crank arms...... I'm selling mine with them).

 The above image is the SRM  control charger and the USB cable that connects the SRM control (display device and recording unit) to your computer for downloading data.  I am selling this with my SRM.  I meant to include it in my top photo, but forgot.  This is an important item.  Small, but important.  I won't forget to ship it. 

Also pictured is a magnet sensor.  It is designed to fit on bladed spokes. (yes, it comes with the SRM).

Pictured above is the spindle that fits inside  any bike frame with a BB30 bottom bracket.  This spindle is 30mm diameter (all BB30 openings are 42mm).  I am planning on selling this item separately, but you will need it if you don't already have one (with two .5mm spacers).  On the left is a wave washer.  It must be slightly compressed once the cranks are bolted on.    The silver ring (bearing shield) has a slight grove and it slides onto the spindle so that the grove fits neatly with the flange of the spindle. This is so that the spindle has a stop and will not drive/tap through upon insertion into the bearings (not pictured) which are already pressed into the BB30 shell.  The spindle is tapped with a rubber mallet, through the already pressed in bearings from the non-drive side.  Then the red bearing shield goes on followed by the wave washer (brass colored), followed by 2-3 plastic spacers, followed by the crank, followed by the crank bolts (pictured in the SRM photo.  they are red)  Note that these bolts have very thin metal washers (these are important for proper tightening and removing).  The bolts are tightened with a torque wrench to exactly 25 foot pounds.  Tada!  Done.  See my video below.  It's actually easy, once you've been shown how and have done it once.  



Hi this is David Henderson from My World From A Bicycle.  In this following video I'm swapping out my SRM crank between my Cannondale Slice Time Trial Bicycle and my Cannondale Supersix Road Bicycle.

 First let me tell you a little about this SRM device that I have just mentioned.  It's an amazing technological device that records true power output in the form of wattage which is calculated from multiple strain gauges built into the crank.  These gauge strips deflect when force is applied to the pedals.  The material deflection registers the force thus created (also known as torque) as well as cadence (also known as angular velocity).  These parameters are converted into a digital electrical signal which is wirelessly sent out to the SRM control device that's mounted onto the handlebars.  The control device can also record heart rate data, speed, temperature, time and altitude data every single second.  This data is easily downloaded to a computer for analysis.

For the techie's out there this SRM crank weighs 721 grams with crank, chain rings and bottom bracket.  The bottom bracket is a BB30 SI-Hollogram and weighs 128 grams.  My complete race ready Supersix bike weighed in at 15.4 pounds on my bathroom scale and my Slice bicycle weighed in at 17.6 pounds.

Wattage or energy output data is extremely valuable for a serious cyclist.  It provides a true measurement for how hard a cyclist is working.  This data can be used to determine power thresholds for racing and training.  Additionally it can help determine if an athlete is improving over time or not.

Old school training data included speed and heart rate measurements.   Unfortunately the measurements don't tell the full story of training.  Speed is highly subjective to wind resistance and road grade or pitch, etcetera.  Heart rate, on the other hand, is subject to conditions such as temperature, hydration levels, conditioning, diet, etcetera.

 The SRM device combines all of these data fields previously mentioned for a more complete picture of performance. 

The only draw back of the SRM watt meter is the cost.  The one that I am switching between bicycles costs $3,000, which is why I only own one and transfer between bicycles.

 Now let me tell you a little about the bicycles in this video.  Both are top of the line professional level race bicycles.  The first is a Cannondale Slice Time Trial Bicycle with a Zipp Sub-9 Rear Disc wheel, and a Zipp 1080 front wheel.  Both wheels have dimpled surfaces to increase aerodynamics, and both wheels are very expensive.  The sub-9 retails for about $2,000, and the 1080 for about $1,400.  I run Zipp 404 tubulars which retails for about $2,000 on my Supersix Road Bicycle, which has a Dur-Ace groupo and an upgraded Specialized Barmac Wedge carbon stem/handlebar combination.  Both bicycles with SRM devices and race wheels retail for about $20,000 combined.  Basically, damn expensive.

Oh, I almost forgot.  The tires which are about $100 apiece are extra.

 In conclusion, high end race bikes are stocked full of engineering and technology.  As a result they are lighter, more aerodynamic, stiffer, handle better, and are just plain fun to ride.

To learn about the best video camera in the world for videoing cycling (which is the cameras that I use for my videos) click here.