Sigma ROX 4.0 GPS Cycling Computer: At The Finish

Sigma ROX 4.0 GPS Cycling Computer: At The Finish – by Guitar Ted

The Sigma ROX 4.0 GPS unit has been run enough now, and it has been long enough now since the introduction post, that I am skipping to the final verdict here. Part of that is due to weather, scheduling, and my having had a wicked head cold which put me off the bike for a few weeks. But enough about that!

The Sigma ROX 4.0 computer head on a mount integrated with a bag.
The Sigma ROX 4.0 GPS computer.

To briefly recap where I was at with the ROX 4.0, I had a good user experience with set up, and basic functions of the GPS unit were all favorable at first. I had to find out about navigation, data acquisition and review, and just see how this computer was to use on the bike out on the local gravel roads here. Following are my thoughts and opinions on those things and then a final verdict on the ROX 4.0 from Sigma will follow that.

Screen shot of the Sigam ROX 4.0 Ride App on a smart phone.
An example of the sort of data generated by the Sigma Ride App

Sensors & Data: The ROX 4.0 can be paired with a cadence sensor, a heart rate monitor, and a speed sensor, although you can also rely just on the GPS signal for speed if you want to. It seems to track alright, if you decide to just go with the head unit for speed data, but I did note that the signal can drop out under heavy tree cover. A dedicated speed sensor, which you have the option of getting and using with the ROX 4.0, will – potentially – alleviate that issue.

What I noted with this first head unit, (yes, there was more than one, read on…) was that the sensors had a hard time staying paired up and would drop out and come back on randomly. This was a bit disconcerting, as you get an alert on the screen if the sensors drop out and when they come back on again. This did not occur all the time, but enough so that I did not trust any of the sensor connections. In terms or recorded data, I did not note “gaps”, so was the sensor still working, or not? Did the Ride app just fill in the gaps? Who knows?

Speaking of the Sigma Ride App page, it does do an okay job on your smart phone of showing you general data. Don’t expect impressive, fine grained data charts or overlays of different data to peruse here. This computer/phone app is a good guide, but if you are looking to drill down at a granular level, this app isn’t for you.

Navigation: Here I was hoping that I did not have to have a smart phone tethered to the GPS head via Bluetooth to obtain turn-by-turn directions, but alas, the 4.0 model does not seem to do that. The more robustly featured ROX 11.0 may do that, but not this unit. And honestly, at the price that the ROX 4.0 sells for, it would have been an expectation too high for such a price-point item to have that feature, perhaps. Oh well…

So, I downloaded a route to the Ride App, opened it up on my phone, and started the ROX 4.0 and off I went. The unit did let me know I was off route and an arrow on the screen pointed in the direction I needed to head for to get back on track. That was a bit vague, but intuitively I figured it out. Turns are alerted by a beeping notification, and are indicated on the screen with plenty of notice. All well and good so far. However, things did not end well.

Remember how I had trouble with the sensors staying tethered to the head unit? Well, the signal dropped from my phone, which was three inches from the GPS unit at all times, by the way, and it would not re-pair unless I started all over again. Obviously that is not a desirable or workable situation for turn-by-turn navigation. Are all ROX 4.0 units like this, or was this just a glitch with the one I have here? Did I have a defective unit?

Due to inconsistent Bluetooth and sensor connections, I reached out and got a replacement GPS head.

Hitting The Rest Button: I contacted my person with whom I had arranged to do this review through and they indicated that it sure sounded like a bad head unit. This person indicated also that this experience I had was rare, and I should hold out on the review until I had some time with this new ROX 4.0. I should also mention that the first head unit was a salesman’s sample, and that it had been handled quite a lot before I had gotten a hold of it, so there is a possibility that it was damaged before I tried it out. But either way, now I was on to another, brand new ROX 4.0

Navigation 2.0: Okay, so what did I have for performance now? I had to wait until the weather cooperated to be able to try this out, but recently I did get a window to go ride with the Sigma unit and things were a lot different this time.

If you get off route the upper right arrow guides you back to the route. The circled bread crumb trail is for normal navigation.

The turn-by-turn was accurate this time with no dropping of the signal. However; I noted an oddity this time that was new, perhaps, and a thing I would want to see Sigma change in the future. It has to do with the small circular indicator in the upper right corner of the unit.

Detail image of the Sigma computer
During typical navigation the upper right arrow ceases to be a guide.. The breadcrumb trail is your friend then.

When you get off-route, the unit beeps a warning, flashes a message on the screen, and the upper right hand circle will display an arrow as to which way you are to turn to get back on route, a useful feature.

However; if you stop, that arrow turns into a pause signal, which is a bit annoying if you want to stop for any other reason. Once you start rolling again, the arrow comes back. The unit then will alert you to when you are back on route. Then the arrow points at the 12:00 o’clock position and a little chequered flag appears. At this point, the arrow is not your friend when it comes to turns. That job then transfers to the bread crumb trail on the lower part of the screen.

At The Finish: In the end, I could use the ROX 4.0 pretty much as I would with a wireless computer – That being for simple tracking of speed, distance, and a few other features of my ride. The Ride App was okay, but compared to a Lezyne GPS ROOT data set which a Lezyne GPS computer uses and would be competitive with this Sigma, you have no comparison. The Lezyne set up is far more impressive.

The navigation is “okay“, but it is a bit strange with that upper right hand arrow being used for off-route navigation, then not being used at all for typical route navigation. I’d prefer that the arrow be used at all times, since it is easily seen at a glance and the bread crumb trail is a bit less obvious. Tethering to your phone for the route turn-by-turn feature is, again, okay. It works, but that’s one more device you have to rely on for your route navigation, and if you ride long, that may not be a great solution. Dang batteries….

The ROX 4.0 showing navigation features.
Note that the upper right arrow points straight ahead but the bread crumb trail veers left. Follow the bread crumbs!

The Sigma ROX 4.0 has an attractive price and feature set. The navigation set is a bit kludgy, and it is not as slick and easy as some other units, but at the price, this is typical. Sensors were picked up and information was easy to draw out afterward. I had no complaints after the first unit was replaced. If turn-by-turn navigation is not at the top of your priority list, I could recommend this for those looking for a entry level GPS computer. It’s got great battery life, it is fairly accurate, and it will do basic things well enough. It’s no GPS unit with “bells and whistles” that you hear about from the typical GPS cycling computer makers, but it does a lot for the price and is easy to navigate and use.

Note: SIGMA sent over this ROX 4.0 GPS Cycling Computer for test and review to Riding Gravel at no charge. We were not paid, nor bribed, for this review and we will always strive to give our honest thoughts and views throughout.


Author: Guitar Ted

Guitar Ted hails from Iowa. Home of over 70,000 miles of gravel and back roads. An inaugural member of the Gravel Cycling Hall of Fame and Co-creator of Trans Iowa in late 2004- Guitar Ted has been at the forefront of the growth of gravel events and riding since then. Creator of Gravel Grinder News in 2008, he produced the premier calendar of gravel and back road events. GT joined forces with Riding Gravel in late 2014.

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7 thoughts on “Sigma ROX 4.0 GPS Cycling Computer: At The Finish

  1. Hi,

    I wonder about navigation part of Your review. It looks like You did not update ROX. Your experience looks like it was before update that was made around Nov.22
    That is what SIGMA is advertising after an update:
    The track navigation allows you to precisely ride a planned route. To do this, create a track in the SIGMA DATA CENTER or with a tour portal of your choice (komoot, Strava, etc.) and import it into the SIGMA RIDE app. You can then start your tour in the app and ride it right away or save it and start it later on your bike computer. This allows you to navigate your tour without a connection to your smart phone.”
    During navigation, the track and turn-by-turn directions are shown on the ROX 4.0 display. A turn arrow and an acoustic signal tell you when to turn next. To make absolutely sure that you don’t miss any path, the red circle shows the distance to the next turn-off as coloured bars that get shorter as the turn-off gets nearer. The ROX 4.0 also shows the street name. If you leave the track, the ROX 4.0 sends you a notification and displays the shortest route back to it. The track view zooms automatically with your speed so that you are never surprised by a curve. If you leave the track, the zoom level is increased automatically so that you can always see the track and find your way back to it quickly.”

    Is it possible for You to check?

    1. @Wojtek – Okay, I double checked the unit, trying to see if I could download the latest update, and I experienced a lot of trouble.

      Initially the unit was not discoverable by the Ride App. So, I checked the settings, which were correct. I checked my iPhone’s Bluetooth settings. It was correct- the unit was displayed as being a device I could connect to. So, still no good on the Ride App. I decided to try and unpair everything and start from scratch. The ROX 4.0 then would not connect to my phone at all.

      Stuck in limbo for now……

      If I get it to pair up and IF the device will connect to the Ride App, we will have answers. but until then? Stay tuned…..

      Considering how much time I have consumed in trying the navigation feature, I could have easily written cues and had a hard copy to navigate from. Something to think about….

      1. Hi,

        did You see Jans post?

        Looks like for him it works as advertised!
        Good news, as I really wanted to like (and buy) this ROX, but the navigation part kept me away.
        It was a bit pointless if I should drain my phone battery anyway – than I’d just rather buy a nice phone mount – it could be luxurious and I would still have some change left…

        Now I’m all in!

  2. Hi gut the sigma Rox 4 for the sole purpose of showing me the distance, time and maybe the speed during my training, without the need to connect a speed sensor to the wheel. I tried different”cheap” GPS speedometer until I found this one.
    When I got it about a year ago, it was good at showing the speed and distance. Enough for me. I was very happy. Navigation worked when it was connected to the phone, by means of arrows either in the circle or in the lower section of the display. It was okay, but for the rides I preferred strapping my phone to the handlebar and use komoot in full screen.
    Then in autumn I got an update and things changed. Heart rate sensor works reliable now. And offline navigation on the device paired with the possibility to show a small outline of the track to follow really changed the device. I am able to set up different screens for the ROX in the app, which I can change during my ride on the device. And there, I can change whether I want to have the navigation in the circle or at the bottom or both.
    In my opinion, this device is all a hobby biker needs. Of course Garmin’s are better but they cost almost 10* more.
    Unfortunately bloggers tend to try out the expensive stuff as they get it for free. And so, the average Joe thinks that biking without a 10k+ setup is worthless.
    That said, I’m always thankful, to read tests for good, fairly priced stuff. Thanks Ted

  3. I’m tempted by this. Presumably it has the usual distance travelled, time, max speed, temperature etc.? I’m not one to follow routes so that isn’t an issue for me but I like to upload routes to Komoot afterwards so I can share with others. I gather this is all available on this unit? Thanks.

    1. @Steve – No temperature read out. Yes, you can upload routes from Komoot. The recently announced ROX range-topping GPS computer probably would be a better deal than the 4.0; however. Check that one out if you are set on running a Sigma.

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