Garmin Magnetless Speed Sensor Review

Garmin Magnetless Speed Sensor Review

As reported a few months back, Garmin have released some new ANT+ sensors to provide alternatives to the traditional crank and spoke magnet systems. Previously I thought I’d probably only need the Magnetless Cadence Sensor, but with an increasing amount of turbo sessions this winter I decided to also invest in the new hub mounted sensor to see how it performed against the magnets.

It’s basically a one piece rubberised pod with a stretchy loop to help fit to most conventional rear hubs. So simple in fact, you can be up and running in seconds.

Opening the Box – Garmin Magnetless Speed Sensor

The box matches the current Garmin trend of black and white with a glossy finish to display the item inside.

Garmin Magnetless Speed Sensor Review

In the box it’s simply the sensor unit and a brief instruction manual. It comes protected in a little black bubble wrap pouch. It’s a very similar design to the new Magnetless Cadence Sensor save for the outer housing which also incorporates the universal fixing loop.

Garmin Magnetless Speed Sensor Review

The sensor contains its own in-built accelerometer to count wheel revolutions via motion rather than magnets.

Fitting

Easy! You just reach between the spokes hold in place with one hand and stretch the loop with the other. Once you’ve stretched the loop over the plastic hook you can let go and spin the wheel.

 Garmin Magnetless Speed Sensor Review

Here’s mine on what you can see is a kinda cone-shaped hub. I read the instructions and Garmin state that the sensor will work equally well on standard or asymmetrical shaped hubs. So long as you have enough stretch in the band, it will work.

Garmin Magnetless Speed Sensor Review

There are no moving parts whatsoever and mounting system is both reliable and robust. The hub position is probably one of the few areas on a bike where nothing else really reaches.

Operation & Compatibility

This image gives some further perspective on the unit itself. On the underside you’ll find a battery compartment which will remain protected being the piece nearest to the hub (when fitted). The only time the compartment is exposed is when off the bike and/or when changing between bikes (which can be done in seconds).

Garmin Magnetless Speed Sensor Review

Pairing is in accordance with your particular Garmin device. I’ve had no difficulties pairing with FR920XT, FR620 & Edge 810.

The Garmin Website lists the following devices as compatible: Fenix 2, Fenix 3, Edge 500, Edge 510, Edge 800, Edge 810, Edge 1000, Edge 500, FR310XT , FR620, FR910XT, FR920XT & the Garmin Epix.

Accuracy

I got hold of sensor at the very beginning of 2015 and have performed multiple rides both indoor and out on the road with the magnetless option pitted against traditional combination sensors.

Garmin magnetless cadence sensor review

In fact, I’ve tested against both the previous Garmin GSC 10 Speed/Cadence Sensor and the Wahoo Blue SC just to double-check against two different magnet based units.

Here’s a little comparison over a 1 hour turbo session. This Garmin chart shows the performance of the Garmin Magnetless Speed Sensor.

Garmin Magnetless Speed Sensor Review

Garmin Magnetless Speed Sensor Review

The second chart shows the same session recorded with the Polar V800 and the Wahoo Blue SC.

Garmin Magnetless Speed Sensor Review

Garmin Magnetless Speed Sensor Review

You can see the results aren’t just near identical, they are identical. I’ve not included any other charts in this review for the simple reason that every single comparison has been the same. Identical!

The point is… the both magnets and the magnetless sensor do a great job at tracking speed. What’s great about this new sensor, however, is the convenience and total ease of operation.

Summary

The ease of use and convenience factor is on a par with the magnetless cadence device Garmin released at the same time. As with that sensor, speed is detected and sent to your paired device without any fuss whatsoever. Once installed, you’ll forget even there as it’s highly unlikely to require repositioning until you either need to replace the battery or swap to an alternative bike/wheel.

To compare with the GSC 10 Combi Sensor you can read the review here. You also complete the set by reading the magnetless cadence sensor review here.

Pros/Cons

Pros

  • Magnet-less
  • Easy installation & mounting
  • Universal application
  • Compact
  • No moving parts
  • Accuracy

Cons

  • No combo option
  • More expensive than the GSC-10

Conclusion – Garmin Magnetless Speed Sensor Review

I really can’t fault this little sensor and I have to say that it makes sense over the previous magnet-based GSC 10. The only slight downside is a small additional cost, however, this is far outweighed by the convenience factor of having no moving parts and the ability to mount and remount on multiple bikes within minutes. The speed sensor can be purchased separately or as a pair (with the magnetless cadence sensor). If you already have GSC 10 on a single bike it’s probably not worth the upgrade just yet, but for anybody using multiple bikes or not yet tracking speed/cadence these newer sensors are the perfect solution.

Buying Options

I want my reviews to be as independent as possible. On that basis, I thought a link to Amazon would provide the most impartial method of you looking at other user comments should you be considering a purchase.

Garmin Magnetless Speed Sensor Review

5 Comments

  1. I have Edge 810. Now I want to buy cadence sensor but I’m thinking also about buying sensor bundle. Is there any added value of measuring speed by sensor instead of a GPS? Is it REALLY more accurate? I’m not professional rider.

    • If you get the measurement of your wheel set accurately the speed sensor will give you true representation of distance. That said, I only rely on the speed sensor when using my bike for indoor training.

  2. I found your article very helpful regarding the fitting of the garmin speed / cadence sensor, the technical info
    and charts were beyond me but interesting.
    I have since followed your instructions and fitted the sensors as shown.
    On my road bike the sensor works well, when I transfer it to my Spinning bike, the speed is shown very
    exaggerated.
    The only difference I can see between the two is that the hub of the spinning bike is larger than the hub of the road bike.
    Can you explain why this is.
    Thank PW.

  3. Frederick Woods
    14/01/2017 at 12:07 pm Reply
    I found your article very helpful regarding the fitting of the garmin speed / cadence sensor, the technical info
    and charts were beyond me but interesting.
    I have since followed your instructions and fitted the sensors as shown.
    On my road bike the sensor works well, when I transfer it to my Spinning bike, the speed is shown very
    exaggerated.
    The only difference I can see between the two is that the hub of the spinning bike is larger than the hub of the road bike.
    Can you explain why this is.
    Thank PW.

  4. Pingback: How to count the bicycle wheel revolutions by accelerometer | Physics Forums - The Fusion of Science and Community

Leave a Reply