Wahoo Case / NK Mount setup

I wanted to use the new Speed Coach Mobile app for rowing, but didn't want to take my phone out on the water unprotected. So far, the only solution is just using glorified ziplocks.

The decided factor for me was when Speed Coach Mobile started supporting getting heart rate with the . I use heart rate for most of my training. I've used SpeedCoach XL2 which has a heartrate pickup, but I found it to be really finicky in salt water, and it didn't record anything. For watches, I started with the Garmin Forerunner 305 and then moved on to Polar's RS800CX with the GPS pod, as I liked Polar's desktop software and having the GPS separate means the watch lasts for a few years, not a few hours. These worked, but I had more devices, and I still needed the SpeedCoach for actual speed and stroke rate, and I needed the propellor for speed, and couldn't see the heart rate constantly.

The other deciding factor was that Wahoo also makes a waterproof Bike Case. The challenge then was how to mount it to my boat.

I figured trying to use the NK T was the way to go. There are ways to do it that work if you have a wing rigger, but I row a fluid, so I have nothing except the foot plate in front of me. I asked the guys at NK to send me a back plate to the SpeedCoach XL. I figured I would combine it with the Wahoo Bike Mount, this way I could still pull it on and off with each row without resorting to Velcro or anything that would weaken over time (and I don't really trust it for this sort of stuff anyway). I took the bike part that attaches to the Wahoo case, and bolted it the NK back plate. Here's a few shots of what I came up with.

And a few with the case attached:

I had a spare harness, so I had that to make sure it fit, and the nut was clear.

Here are some shots in the boat, to show you the final setup:

So far, it's worked quite well. It stays in place, I can pull it in and out like a speed coach, and I know the phone is safe from water. I drilled out one of the small holes so I could put a lanyard on it, for kicks.

As far as tracking, I'm using Training Peaks. Speed Coach Mobile can export to TCX format, and Training Peaks can import those directly. Training Peaks can show graphs for speed, rate, and HR, and can show tracks on maps as well. I'm right now working on a script that will convert all my Polar data files to TCX format, so I can convert my full history to Training Peaks.

Going forward, there are a few options. NK makes a "T" that doesn't have any wires, that they use for the SurgeRate. Once I'm full confident in this setup, I'm considering removing the full SpeedCoach rig, including the wire harness, seat magnet, and (most importantly) the impellor. It's not frequent, but the impellor picks up stuff, and can be a hassle. I've had it happen at St. Catharine's, for example. Wahoo also just came out with an Aerobar Bike Mount that may be more stable with this setup. Additionally, if you don't ever need to slide a speed coach back in to the rig, you could just bolt the Wahoo bike mounts directly to the NK T.

This setup is obviously vulnerable to current and tide. I mostly row on tidal water, which was part of why I kept the SpeedCoach for speed, but being able to simplify my setup has finally changed my mind. I haven't had issue with battery life, yet. If you turn off Wifi and Bluetooth, it can last a while. (You can't do "airplane mode" cause you need the GPS.)


Wahoo came out with a mount for the Aero bars, so decided to use them to try to make a better mount:


I cut the tabs off the main part, and drilled holes through both it and the T and bolted with short bolts I had lying around. This makes for a more stable mount to the boat, and less "stuff". Only down side is I can't use a regular speed coach anymore. Only issue I had was the mount had a bit of a taper to it, which I had to cut down so it sat flat on the T. Otherwise, works really well.

Once I had this rig sorted out, though, I was able to remove the wires, impellor, and magnet. Nice having less stuff in the boat.