New Sigma Rox Shows Gear Inches, Altitude & Incline, Ghost Races & Measures Power Just for Fun

Sigma’s latest version of the Rox mountain bike computer tracks all the essentials -41 to be exact- with some interesting new features that make the $229.99 price not so much of a shocker.

All the expected speed, distance, maxes and whatnot are there. What sets the Rox 9.1 apart is its ability to measure gear inches, which they call “expansion” by comparing speed and cadence to determine the gear ratio. For a racer, this lets them compare various perceived exertions with actual heart race, cadence and gear ratios to determine the range where they perform best. It also helps identify duplicate gear ratios between chainring/cog combos.

On top of that, it measures power. Yes, for under $250, you get a computer that measures power, but here’s the catch: It’s most accurate when climbing and it’s really an estimate based on rider/bike weights, body size, gender and a few other factors that you input. Even Sigma’s marketing director Gindi Orloff admits it’s more of a “just for fun” feature, but combined with the HR, cadence and other features, it helps paint a broader picture without dropping four figures to get into the power game.

Lastly, the Rox 9.1 can record your rides (distance and speed, not GPS info), which is uploaded into their Data Center program along with all the other info. From there, you can create a logged ride and reupload that info to create a ghost race. Once loaded, simply start the virtual race at your usual starting point for that particular ride and it’ll tell you if your ahead, behind or on pace compared to your prior ride.

The 9.1 comes with both cadence and speed sensors, HR chest strap monitor and docking station and Mac/PC software. The 8.1 loses a few of the features, in particular the ghost race, and doesn’t include the docking station.

Comments

cat 1 doper - 04/16/12 - 11:09pm

sigma makes nice bike computers. decent prices too.

craigsj - 04/17/12 - 5:27am

“On top of that, it measures power. Yes, for under $250, you get a computer that measures power, but here’s the catch: It’s most accurate when climbing and it’s really an estimate based on rider/bike weights, body size, gender and a few other factors that you input.”

In other words, it doesn’t measure power. It speculates and is useless.

Collin - 04/17/12 - 7:48am

@craigsj, agreed. At least something like the iBike factored in windspeed, so if you were drafting someone, it would show a lower output. For this thing, the displayed units would be higher if you were drafting off someone, or had a tail wind. Worthless.

NotJensVoigt - 04/17/12 - 10:27am

@Craigsj, @Collin, It’s a mountain bike computer. Not too many people are going to be slapping $2000 Quarqs on their trail rigs, and drafting at 10 miles an hour doesn’t make a difference when you have knobbies rolling over dirt, roots, and rocks. Plus, it’s probably useful to measure relative power and exertion, even if the total power measurement is off.

Michael - 04/17/12 - 9:28pm

@haters. Any power meter that is consistent in it’s ‘speculations’ is useful, even if it completely inaccurate.
If it gets it wrong by the same amount each time, then you can gauge your progress from that. Oh, I’m sorry, I was talking training methodoloy, but you guys obviously just like to chase leaderboards on strava…

Pancakes - 04/19/12 - 6:52pm

@michael You’re missing a big part here, this ain’t a power meter. A power meter that reads consistently low or high does have training value, but this thing throwing out numbers that don’t account for climbing v. descending, coasting v. pedalling, wind, health…..

Not valuable.

Also, the leaderboards on Strava are based on time to cover a segment based on GPS, not wattage. That’s something this $230 device can’t do, but a $250 Garmin Edge 500 (or a $150 Edge 200) can.

And why do I like Garmin on my MTB? No speed sensors required, and a secure mount. I can’t speak for the latter in this case (though I’ve never been fond of Sigma mounts), but I know it can’t do the former.

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