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Wahoo Kickr

I sold my Computrainer having got in on the first shipment of the Wahoo Kickr, with which I'm very happy. Much has been written about the Kickr, here I share my thoughts and describe how I configure and use the device.
Full disclosure: I'm a listed coaching dealer with Wahoo (contact me for info), but that's not the reason I advocate the Kickr over rivals such as the Computrainer, Lemond, and Cyclops.

Here's my setup, complete with Powercranks (click to enlarge):
                        


Erg Mode:

Like the Computrainer, the Kickr can be used in Erg mode, where the rider selects a power at which they want to ride, and the Kickr maintains this required power regardless of cadence. This is how I do most of my training.

Communications:

The Kickr transmits and receives data wirelessly over 2 protocols:
    • ANT+
    • Bluetooth 4 (also called BT4, BT smart or BT low-energy) and ANT+
Since May 6th 2013 Erg Mode is now supported by both ANT+ and BT4. However firmware updates to the device can only be performed via BT4, using either the Wahoo app or TrainerRoad.
BT4 is not yet fully supported Android devices with Android 4.3 higher, and I've had my Droid Razr with 4.4 work successfully with the Wahoo Fitness App, which is still in beta. 

Software:

Windows tools such as the free Golden Cheetah (GC) can still communicate via ANT+, so GC or TrainerRoad ($10/mo) plus an ANT+ dongle will be a good option if you have occasional access to an iDevice to perform firmware updates to the Kickr (the addition of cadence directly from the Kickr, calculated by software, was promised but it seems this will not be delivered, so a BlueSC or RPM sensor is necessary for cadence).
Another PC option is PerfPro Studio, which supports Erg Mode, course upload etc, for $100.

I have successfully used my Android phone to obtain Power and HR data using an OTG cable, an ANT+ dongle, and the ipBike app. It worked well, albeit without Erg-power-control so far.

For now, an Apple iDevice that supports BT4 is the simplest option. I'm using an iPad Mini, though a 5th Gen' iPod Touch would suffice.

Here's a quick summary of software available to work with your kickr:
  • The Wahoo Fitness App is free, it has some trivial shortcomings which I and others have reported to Wahoo, but is a good solution which will only improve. During cool-down you can upload your workout data to strava. Available for IOS and Android. This is the App I use the most, including for Treadmill runs.
  • TrainerRoad at $10/mo fully supports the Kickr, including firmware updates. Works on a PC, Mac, iPhone or iPad (not Android). Integrated FTP tests and workout suggestions etc.
  •  Golden Cheetah communicates via ANT+, is free, and has several power analysis tools. Needs a PC with IOS, Windows or Linux.
  • Segments is a Wahoo App that allows you to ride any Strava segment in the world. I haven't yet tried this, and don't feel the urge to since without accurately matching several parameters, you won't be comparing your effort with an effort on the road.
  • www.bulltrainer.com is the most pointless app. This one allows you to ride any Company's Historical Stock data graph. Declining stocks obviously make for easier rides.
  • imobileintervals.com. is my favoured app for interval workouts. This is a $5.99 (one-time-payment) app which integrates with the website, where you can design or import workouts, and can also share workouts with others. It has a lot of Kickr-specific features. For interval rides in Erg mode it's the perfect tol, no more adjusting up and down on the icons at the start and end of every interval, and it has override capabilty for days when you're just not feeling it, half way through a workout. There are numerous features and development is still on going at a great rate.
  • VirtualTraining provide a subscription option with Mac, IOS and Windows support with ANT+ and BT4. It's subscription-based, $10-$15/mo.
  • Hurts Development has an iPad/iPhone option made specifically for doing intervals in Erg mode, it's free but requires an in-app purchase of $2-3.
  • BKOOL have an IOS and an Android (possibly only ANT+) app..
  • VeloReality have PC software which controls the Kickr, and integrates with their videos.  The software is free, they sell the videos.

Calibration and accuracy:

Like the Computrainer, minimizing wheel speed can ensure more accurate power data. Thus ride a relatively low gear (not as per the photos above).
This minimizes flywheel speed, so allows the device to better calculate the exact power being dissipated.

Reports suggest that calibration after warm up is optimal, as was the case with the Computrainer.

The image below shows the ANT+ Quarq output from my race bike, passed to my Garmin 500, and displaying the 30s average power. The iPad shows that the Kickr is in Erg mode at 340W. I kept the cadence as constant as possible so as not to affect the 30s average. The instantaneous power from the Kickr is 341W, but the long term Kickr average is 340W. Both the Quarq and the Kickr were calibrated twice preceding this test. The Quarq typically reported 341 to 344, however when cooling down at 240W the Kickr reported about 1% lower than the Quarq. All of these results are within the margin of error on either device, let alone the compounded error of using them simultaneously. Also, we'd expect the Kickr result to perhaps be marginally lower do to chain transmission losses.
The test was done at low effective wheel speed (approx 17mph), in a 42X17 gear, so as to minimize transmission losses by having a straight chain and low flywheel speed.
What it doesn't do
  • Cadence (A firmware update to provide this was promised, but now will not be delivered, the reliability of cadence via software being too poor). You can simply use the BlueSC sensor or RPM Sensor to get cadence data.
Future Options:

Several other apps are also available which support the Kickr to some extent, and more are in development.

One could also use Golden Cheetah in Erg mode with a PC. Additionally, it would be nice to have a trackball and/or keypad at the bike for control, and then use GC's google-street-map based options to ride any road in the world that the google car has traveled:


Another good option is the subscription-based Kinomap, which supports the Kickr and allows real course video with power-replication to reflect the terrain. There are rumours of open-source (and thus free) alternatives.

My configuration

  • I have a dedicated trainer bike, so can strap a big fan to the bars and jury-rig an Akron tablet holder to hold my iPad Mini. 
  • That's a paper-towel holder fitted to the treadmill next to the bike.
  • There are two cut-off water bottles for holding remote controls.
  • Rather than having wires running on the ground, one power strip drops down from the ceiling, and the Kickr, iPad, fan and headphone-charger all connect to it behind the fan.
  • I have a Blackburn sweat catcher, and two water bottle cages (one on the head tube).
  • The fan has a remote and also an electronic switch at the front, no more reaching around the back to turn up the breeze.
  • There's no need for a front wheel support since the Kickr's height is configurable for different size wheels.
  • Any Bluetooth-4 HR strap should work, I'm using the Wahoo BlueHR, with which I've had no problems.
  •  use the BlueSC sensor to get cadence data, but all you need is the Cadence Sensor.

What the heck's with those handlebars?

My saddle is a long way back, so very high pads and upturned bars allow me to watch TV without straining my neck, while still somewhat replicating the hip angle of my race bike. I flipped a pair of old tri bars upwards, chopped the ends, and inserted expander bolts for the pads, it's a hack that works very nicely. This bike is never going on the road.


Entertainment on the cheap
  • The headphone charger cable is affixed to the fan. 
  • My TV is hot-wired to the upstairs DVR, and I use a $6 hard-wired remote control transmitter plus an active-HDMI-splitter so I don't need another set-top box, while still being able to watch recorded shows.
  • I also have a $35 Raspberry Pi running XBMC. That enables full media access from the internet and to movies and music stored on my PC, and uses the TV's own remote control, via HDMI-CEC.

Speed data on indoor trainers

Here's a recent ride I did on the Kickr, which the Wahoo app automatically uploaded to strava.com:

Note that since I'm using a low gear in Erg mode (in order to increase accuracy), the "virtual wheel" is turning slowly, and 340W at 90 rpm only gets me about 17mph. At the same power, I could ride a higher gear or spin at a higher cadence and record a much higher speed. However speed is irrelevant on an indoor trainer.
I'll repeat that...
S p e e d   i s   i r r e l e v a n t   o n   a n   i n d o o r   t r a i n e r.
This is especially so in Erg mode, and obviously applies to distance too.
Even when not in erg mode, and even if the program tries to allow for your age, gender, body weight etc, it can only approximate your cross sectional area and rolling resistance, while it doesn't know what position you're in at any given time. 
For most of my workouts I record the power and time information, and in my log I make an educated guess at the effective distance I would have recorded. Don't be like a certain coach I know who spins a giant gear on his Computrainer in Erg mode for an hour at sub 300W, then records 30 miles in his workout log...
You'll get better accuracy and quieter operation riding a low gear in Erg mode. I use 42x17. This means that at 350W and 90rpm I'm only recording 18mph, so the data uploaded to strava looks somewhat short. One option to slightly reduce that effect is to adjust the virtual wheel size to use MTB 29-er wheels, which are 2.3m in circumference.



Please let me know what else you might like me to write about regarding the Kickr.

Pics: All locally hosted images are Copyright of Doug Clark