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Cog Display


This app calculates the gear ratio that you are currently using based on your cadence and your speed. Since it is impossible to determine what chain ring you are using, the app will display all the estimated cogs. For instance if you have a double chain ring 34/50, it will display the estimated cog for the 34 chain ring on the left and the estimated cog for the 50 chain ring on the right. It works for single and triple chain rings as well. </p>

What’s New

Bug fix (1.0.4): On Edge 520, the display was very small. I believe it is now fixed with this version, but it is hard for me to test it since this bug does not appear in the Garmin simulator.</p><p>(1.1.0): Added support for Fenix 3 watch

Additional Information

  • Edge® 1000 Edge® 1000
  • Edge® 520 Edge® 520
  • Edge® 520 Plus Edge® 520 Plus
  • Edge® 820 Edge® 820
  • Edge® Explore 1000 Edge® Explore 1000
  • Edge® Explore 820 Edge® Explore 820
  • fēnix® 3 fēnix® 3, quatix® 3, tactix® Bravo
  • fēnix® 3 HR fēnix® 3 HR
Average Rating: (44 Ratings)

Jose Gonzalez
January 7, 2021 | Version 1.1.0-upd1

la he usado en mi garmin y es fantastica.Estaria muy agradecido si pudiese instalarla en mi garmin 1030 plus.gracias!

Sergio Montoya
November 13, 2019 | Version 1.1.0-upd1

Works perfectly, very useful and it only takes a couple of seconds after changing the gear to show the current one

Maciek K
October 8, 2019 | Version 1.1.0-upd1

Thank you for this app. Very useful and worked perfect on my E1000. I do not know how I can do without it on my new E1030. Do you intend to upgrade for new Garmins?

Turbo Aspro
July 14, 2019 | Version 1.1.0-upd1

AN excellent little app that works very well for me - quite responsive - only one or two pedal turns and it s spotted the gear change. Merely a matter of personal preference but i would have preferred a cog number 1-10/11/12 rather than the number of teeth

paulo rogerio da silva
January 19, 2019 | Version 1.1.0-upd1

Not for 12 speed.

Peter Crosbie
December 5, 2018 | Version 1.1.0-upd1

Perfect on my 520. After only one ride, I wonder how I got by without it all these years! One star less for the image size. Using it in a 4-field display, and it's smaller - though not by much - than the other numbers.

November 29, 2018 | Version 1.1.0-upd1


Martin Littlewood
October 24, 2018 | Version 1.1.0-upd1

Please update for to enable a 12 cassette

Aurélien Dorgeret
October 3, 2018 | Version 1.1.0-upd1

C'est pour moi l'appli la plus utile installée sur mon 520. Elle permet d'éviter les croisements de chaine et de mieux gérer et rapidement ses rapports. Même en Mono-plateau elle reste utile car elle permet de vérifier quel pignon est utilisé sans regarder entre ses jambes ! C'est juste dommage qu'elle ne gère pas plusieurs profils quand on plusieurs velo avec des braquets différents et un seul compteur.

September 5, 2018 | Version 1.1.0-upd1

Fantastica, esperando la actualizacion para el 1030

Hans Lindskog
September 2, 2018 | Version 1.1.0-upd1

No support for 12 Cog systems, please add! First time using it today. The calculation does not work att all, it desplayed cog 12 almoust all my ride.

Andrew Phillips
August 1, 2018 | Version 1.1.0-upd1

Downloaded, installed, easy set up in Garmin express, went for ride tonight, works perfectly, Thank you, all those years of glancing down and back because not sure of what gear I was in (gone)

July 22, 2018 | Version 1.1.0-upd1

Fantástica, la uso en la bicicleta en la que no llevo el di2, funciona perfectamente si has introducido los parámetros correctos. Voy a cambiar mi Garmiin 1000 por el 1030, una pena que todavía no sea compatible con este último, ojalá actualicen pronto para hacerlo funcional con el 1030. Excelente trabajo.

June 22, 2018 | Version 1.1.0-upd1

Just downloaded this the other day and used it on my road bike (50-39-30; 11-34). What an excellent addition to my 1000. Is there an easy way to set up more than one profile—I have 2 wheelsets I use on my road bike, with different sized tires on each; and a wheelset on my MTB and one on my hybrid? Also—do you accept donations?

Developer Reply
June 27, 2018, Clement_Barthes

Hi mikennn, Thank you very much for your comments. It would be possible to have different settings if Garmin allowed us to install the app twice. Then you would use Cog_1 data field for your road bike and Cog_2 data field for your MTB. I sent them an email suggesting that, but they never replied. One option would be to publish the app twice, but what about people with 3 bikes etc... Thanks a lot for your generosity, but I do not have any donation platform.

June 18, 2018 | Version 1.1.0-upd1

Très pratique. Fonctionne super bien !!!

June 9, 2018 | Version 1.1.0-upd1

Very good. Can you update to Garmin 1030?

April 13, 2018 | Version 1.1.0

Great app, keep up the great work!!

Hybrid Noob
March 13, 2018 | Version 1.1.0

Stumbled upon this and gave it a try on the trainer at first - all good and impressive but surely it can't cope with the gradient changes outside? How wrong I was! I'm incredibly impressed with the accuracy, having just returned from a ride over very varied terrain. Within a second or two the display was consistently showing the correct cog, whether I was powering along the flat or out of the saddle while climbing a steep 15% incline. It now has me wondering quite how it calculates the ratio so accurately, in spite of all the gradient changes, using only cadence and wheel speed??? :/ The one exception is, understandably, when you are spinning out going down a downhill. Of course that's a total non issue given the second you are putting out any meaningful power the display corrects almost instantly. All in all a wonderful little app. For someone who occasionally loses track of the gears and glances down at their cassette this is a nice quality of life addition - if gear display is good enough for Di2 this app is good enough for everyone else!

Developer Reply
March 16, 2018, Clement_Barthes

Hey Hybrid Noob, thanks for the kudos! To answer your question, it calculates the ratio using error minimization. Instead of coding IF LESS THAN but MORE THAN etc... you can compute the error between the measured ratio and the ideal ratio of each cog/chainring pair. Once you've computed all the errors, you rank them and display the lowest one...Tada!!! This approach always give great results . You can check out my code if you click on the source code link, it's very simple if you code a little bit.

Álvaro Carreras
October 14, 2017 | Version 1.1.0

Una aplicación indispensable, me encanta ya que no tengo que mirar atrás para ver en qué corona voy. Gracias a esta aplicación me he aprendido de memoria los piñones que tengo.

Paumier Jean-Michel
October 6, 2017 | Version 1.1.0

Presque parfaite... manque juste deux petites choses : le 12ème pignon et pouvoir visualiser le graphique dans Garmin connect. Merci

October 3, 2017 | Version 1.1.0

Fantastic. It works perfectly. Simply and clear. Thank you so much.

Peter Schneiderhan
September 3, 2017 | Version 1.1.0

I miss the Setting for my 1x12 Speed Chainrings

Nico G
August 8, 2017 | Version 1.1.0

Super application ! Fonctionne vraiment bien et rapidement. Un plus serai de pouvoir avoir l'historique des valeurs / log dans l'activité Garmin Connect Merci !

August 2, 2017 | Version 1.1.0

Bravo et le fait de proposer le code source c'est un super exemple. Reste plus qu'à connecter ça avec un Di et on a une boite auto :)

July 25, 2017 | Version 1.1.0

de la balle , hyper réactif , que du bonheur plus besoin de regarder la roue arrière.....

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