Wrist Mounted Cycle Computer

Without handlebars, mounting a cycle computer in visible location on a uni just isn’t possible. Wrist mounting and a wireless sensor system is an alternative.

I bought a Sigma ROX 5 with wireless speed, cadence and heart rate sensors. It comes with a wrist mount but it is configured to automatically suppress the cycling functions when mounted this way. I contemplated rewiring wrist mount contacts to the cycling configuration but found a better solution.

In an “undocumented feature”, the back of the cycle mount happens to snap very securely inside the hole in the wrist mount. This not only solves the configuration issue but affords full 360 degree continuous rotation to the computer. The cycle mount is also far more sturdy than the wrist mount.

The back of the arrangement isn’t entirely smooth so would need some kind of a backing added if it were to be worn on a bare wrist. I wear wrist guards so it doesn’t matter because the reinforcement in the guard does the job.

However I found it quite difficult to put the supplied band on around the wrist guard. My solution to this was to strap the mount to the wrist guard with a short piece of hook-side velcro passing through the thumb hole and around the outside of the guard. It attached itself securely to the furry-side velcro on the guard and lining inside the guard.

Moreover with using the piggybacked mounts, the computer sat somewhat proud around the wrist. Where I mounted it, the computer sits lower in the bend of the guard.

The speed and cadence sensors are designed to project a beam towards the computer, so need to be directed appropriately. It also made sense to mount the computer on the hand that usually held the seat handle and aim the sensors toward it.

As mounted on the front of the right fork in the photo, the (upper) cadence sensor points considerably forwards of the seat while the (lower) speed sensor is almost at the maximum recommended distance from the computer. I wasn’t expecting them to work if I waved my arm about but testing from riding position I was not able to put my wrist anywhere that lost the signal from either sensor. Perhaps the signal is less attenuated in the absence of a big conducting handlebar right under the computer.

I found it easy to read the speed while rising but cadence and lap digits are a little small.

The ROX 5 has an extensive range of features including 100 lap timing and ten second interval recording that can be downloaded to a computer with an optional adaptor and software. Two cycles can be recorded independently. The cadence sensor has a setting which allows the computer to recognise the sensor and sync with the correct logging system.

The ROX 6 includes a barometric altimeter too. With a slightly larger screen the buttons below the screen have been moved onto the bottom edge and might be a prone to accidental operation in some positions. I will probably try one of these units some time rather than just buying a second set of sensors to use on another uni.

Those who require GPS functionality could consider a ROX 10. I didn’t look hard enough into its specs but I know some GPS enabled cycle computers rely on GPS for speed and distance rather than a wheel sensor. As such they can miss corners and are less accurate. Moreover it might start to become a bit large for wrist mounting.

I didn’t know that anyone made a wrist wearable cycle computer. I figured that i would have my phone with me anyway, so i bought a Pebble Time. It was $160, and uses the phones GPS to feed data to the cycle app. So a little bit more expensive, and even moreso if you want a hardware speed, cadence, and heart sensor. Sensor compatibility is based on your phone, so BT is likely, and Ant+ is possible. Anyway, it has been great as a cyclometer, and it does a lot more.

Had i bothered tomfind out if anyone made a wrist cyclometer i might have opted for the Sigma at the time. Now that I’ve been using the Pebble for a few months I don’t think that I would go back to a cyclometer. The Pebble just does so much more, and the cyclometer app (Ventoo) is quite good. This function was certainly a primary factor in my decision to get it.

That’s not a bad idea at all. I like how it looks like a cool cybernetic gauntlet when combined with a wristguard. :stuck_out_tongue:

I’ve always thought about the cycle computer “issue” on a unicycle although the only one I’ve ever used was on my road bike and all I used it for was my speedometer. And I also remember wiping out somebody’s mailbox when I spent too much time looking down trying to hit my maximum speed on that thing.

25.43mph, by the way. Plus the cost of a new mailbox. :roll_eyes:

It’s overkill for that purpose, but some people might also look at the Recon Jet as an alternative. It’s a glasses-based computer that can project a semi-transparent HUD into the bottom of the user’s view, and is designed for athletes, specifically cyclists. And it’s Android based so new apps can be written for it as needed by the userbase (or just you, if you’re crafty).

Basically, it’s Google Glass for athletes instead of sweaty neckbeards with social phobias.

That’s exactly what I thought! I love the look of it attached to the glove instead of on the wrist :smiley:

As for the device itself - cool idea, I like the idea of a cadence sensor too. Would love to see how much faster at spinning the uni I am than the bike :sunglasses:

I have one of these: Unisex GPS Watch - Aldi — Great Britain - Specials archive sorry for the crappy link, but the others all show the 2014 version which is a bit different - they’re supposed to be Aldi exclusives for their Tour de France sale, but I grabbed one on eBay for about half the price :roll_eyes: It’s decent, and spits out a .tcx file you can open in GoldenCheetah or Strava. My first one melted a bit - the charging contacts on the back aren’t quite flush with the back, and so the plastic casing got burnt by the heat I guess. Manufacturer replaced it no questions asked, and the new one’s been working since. It even comes with a little plastic mount to attach it to a handlebar if you really wanna use it that way.

I like your device though. Cadence sensor sounds fun :smiley:

Well it isn’t really since it normally suppresses the cycle functions when mounted on the wrist band. It was just that I was able to combine the two mounts to make it work as a wrist mounted cycle computer.

I have the USB cradle and software now. Was only about US$25 and included the software license but I couldn’t buy it in Australia. Had to order from Amazon. The postage to Australia was only $9 but it was slow.

It all works well. Importing data is very simple. The software is easy to use and has a field to write comments and automatically identifies the breaks (and UPDs).

Rox 6 with the altimeter would be much more informative.

The cadence is mostly too hard to read during the ride but nice when on the graph. Of course it is proportional to the speed anyway so I tend to set my goals as speed rather than cadence.

I like being able to keep track of how far I have ridden and the actual time spent riding. Time spend wheeling the uni as I walk can be easily seen but it counts as part of the ride statistics. I sometimes avoid this by carrying the uni when walking but alternatively, the software can be used to cut sections out.

The logging is at ten second intervals and it shows my speed is quite erratic which I expected. Could be a good tool to measure progress in cadence consistency. I would like to be able to adjust the interval to sacrifice the 20 something hour storage capacity with a two second recording interval.

I have UPD a few times trying to look at it but I am getting better.

The sensors have moved during UPDs a couple of times so should be checked for proximity to the magnets before remounting. Might be tighter with the zip ties. I have it mounted with the rubber rings because they are removable.

I would be curious of the ballpark numbers regarding cadence & speed with your wheel size & crank length as reference point.

I haven’t looked at cadence measurement devices much but I always wondered how fast I am pedaling (counting isn’t accurate and I haven’t tried math given a constant speed… :smiley: ).

Just me

I know myself. I would tumble and smash a wrist-mounted monitor on one of my first few rides.

I even take off my wristwatch when I ride. :slight_smile:

My first post… (Yea!)

I’m just learning to ride a unicycle, but have been bicycling for years and years. I use a Garmin Forerunner 310xt as my bike computer. I think it would be perfect for what you describe as it is really designed for triathletes.

It comes with a wrist mount (picture watch band) and bike mount. The speed/cadence sensor (wireless) is extra, along with the heart rate monitor strap, but it doesn’t “know” if it’s on your wrist or a bike. It also has 3 settings for different bikes, which could be set for different unicycles based on the wheel size. It will track speed and distance on its own, using satellite info. Since its been years since I purchased mine, I can’t speak accurately to price, but I’d imagine you could be set for around $200USD (mine actually did come with the heart rate strap), but it was new so cost more than it would now. Hopefully I can get the picture to show up…

Well, here’s a blog post (not mine) with a big write up on it, and lots of pics.