# Carbon Drive Belt Tension Tool — user reviews > 63 indexed App Store user reviews of Carbon Drive Belt Tension Tool by Gates Corporation, rated 2.70/5 from 21 ratings. - Source: https://appshunter.io/ios/app/carbon-drive-belt-tension-tool/id438346486/reviews - App overview in markdown: https://appshunter.io/ios/app/carbon-drive-belt-tension-tool/id438346486.md - Rating breakdown: 5★ 6 · 4★ 1 · 3★ 2 · 2★ 4 · 1★ 8 ## Newest reviews (16 of 63) ### 2/5 — Mic simply doesn’t work. Very inaccurate. *2025-02-05, version 2.7.8* Perfectly silent room, completely usable iPhone 15 Pro, readings are all over the place. Strum it 10 times, I’ll get 4 readings from 20-28 hz, a few readings around 40-50 hz, and the rest above 75 hz. There is no way I could trust taking any of these as an indicator or whether I need to go looser or tighter on my belt. Luckily I have the Gates Krikit gauge. I can click that thing 50 times and get 36 lbs every single time. I was more or less just hoping this app would be a useful reference out and about if I’m without the Krikit. I give the app a couple stars for the calculator and suggested tension chart. But the microphone tool is no bueno and almost more of a liability in my mind. I’d be worried that someone is going to take their readings and go too loose and end up shredding their belt or worse they go too tight and cause the bearings on an IGH to explode. ### 2/5 — Too sensitive, also doesn’t work anyway *2025-02-02, version 2.7.8* First of all, I don’t do bike maintenance in an anechoic chamber. But even when I did get it as close to silent as possible in the real world (inside, heater off, no people or pets in the house, no moving my body except to pluck to belt, no breathing while the mic is on), I never could get four similar measurements with the crank in the same position (which seems like a prerequisite for trying it with the crank in different positions). A typical set of four would read something like 52 Hz, 98 Hz, 32 Hz, 87 Hz. Tried it on two different devices, so it’s not a mic issue. I give up. ### 3/5 — Could be better *2024-08-02, version 2.7.6* I wanted to check my bike’s belt tension. This app is a noble attempt at making that easy, but it falls a bit short. First, you *really* need to be somewhere very quiet otherwise your readings will be drowned out. Second, the app seems to have trouble with harmonics. I’d often get readings of 25hz then 50hz then 25hz again. To be honest a spectrograph might be more helpful than a single number. ### 3/5 — Barely good enough *2024-07-22, version 2.7.6* I have now used the app multiple times. I used it on my Priority 3 speed bicycle. I have gained some experience adjusting the belt and using the app. The app is very sensitive. Ignore the many false readings. I delete them so I know where I am. Things have to be completely quiet. This is essential. You will still get false readings. That was the only part of the app I used. I would also recommend that the average tension reading be ignored. I had an odd sensation when pedaling in second gear when my average was within range but there was a spot that was tighter and out of range. That’s not an issue with the app but a helpful tip. I also recommend squeezing the belt when tightening the axle nuts. Only measure the tension with the app when they’re tight. The Priority website is helpful, if brief. Having the bike upside down on the floor is better than in a stand. Finally, plucking the belt makes your fingers sore quickly. There are actual tools out there for measuring belt tension, but the app is free and good enough for doing it occasionally. ### 2/5 — Warum nichts auf deutsch? Funktion, naja… *2024-06-20* In einer stillen Umgebung mag es vielleicht funktionieren und mit einwenig Geduld, aber die kleinste Bewegung oder Atmung verfälscht das Ergebnis schon… Aber dafür, das es kostenlos ist, kann man nicht meckern. ### 3/5 — Tip for more consistent readings *2024-04-23, version 2.7.6* I have found that if you rest the smartphone firmly against the chainstay of the bike whilst taking the readings the results are better. My theory is that the bike frame helps to slightly amplify the sound of the belt. Ideally use a smartphone that has a soft case - eg leather or silicone so as not to introduce additional vibration noises. Be sure also to orient the phone so the microphone is still close to the belt as per existing guidelines. Further tip - when first open the app and go to the test mode - immediately mute the microphone using the on-screen microphone switch in the app until you are ready to proceed with the belt-plucking. Feel free to repeatedly mute whilst rotating the crank to different position as Shimano IGH hubs will make noise when back-pedaling in certain gears. ### 2/5 — No consistent reading *2024-03-11* Not getting a consistent reading, the measurements are all over the place, from 25 Hz until 90 Hz. ### 4/5 — This app does work surprisingly well but, it could be improved with a simple update. *2022-09-13, version 2.4* I own a priority 600, & this app does help with tensioning the belt when used correctly in a quiet room, but it could be much easier with a simple feature. Please add a “pause button” for in between “plucks” I can’t rotate the crank 1/4th turn without a bike stand else I get a false positive because of other small noises. ### 2/5 — Cool Idea *2022-08-16, version 2.4* Cool Idea, doesn’t work well. Spouts out random readings when I’m not plucking belt, then spouts out values from 20hz to 70hz when I’m plucking the belt. ### 2/5 — Nach update nicht mehr so gut *2021-06-09* Bis vor einem Update, bei dem die komplette UI umgestellt wurde, funktionierte das sehr gut! Ein befreundeter Radmechaniker wollte es mir nicht glauben und hat mit seiner Lehre nachgemessen und musste dann gestehen, dass ich als Laie das sehr gut gespannt habe. Leider ist jetzt nach dem Update sehr schwierig den Ton aufzunehmen. Es muss sehr oft gezupft werden, bis die App den Ton aufnimmt. Das war vor dem Update besser bzw. hat es immer direkt geklappt. ### 1/5 — The previous one was so much better *2021-04-28, version 2.1* The previous version of this app was amazing. I used it on car and motorcycle belts. This latest version is utter rubbish. The best of three system throws some amazingly wild results to the point you lose faith in this app and just go looking for another. I’m not risking my engine to this app. No way. Id say to anyone just avoid this app in its current guise, whereas a year ago id have recommended it to anyone. I’d really just stay clear and as said, no way I’d risk an engine rebuild because of this now currently substandard product. Gates- please look at what last years app was doing and try and analyse where you’ve gone so wrong. ### 1/5 — Doesn’t work, erratic measurements *2021-04-02, version 2.0* Plucking the belt I get anything between 39 and 87 at the same spot. Obviously not a reliable way to measure tension. ### 1/5 — Crashes on startup *2021-01-27, version 1.7.7* iOS 14.3. App needs updating. Useless now. ### 1/5 — Bug - App startet nicht mehr *2020-12-01* iOS 14.2 iPhone 11 Pro ### 1/5 — Crashes while using. *2020-11-15, version 1.7.7* App does the job well when running. Crashes in use though. Time for an update guys. Not a good reflection for Gates as a company. Update please to fix issues. ### 1/5 — Starter nicht *2020-09-27* Du App stürzt währen dem Startvorgang ab. ## Most critical reviews (10 lowest-rated) ### 1/5 — Useless *2026-08-05, version 2.7.11* Opens up on with the mic running and starts to register frequencies before the belt is plucked. Far too sensitive. Very inconsistent readings. No way to clear all frequencies already recorded. Total waste of time. ### 1/5 — Stürzt immer ab *2026-05-26* Stürzt ab bevor jemals irgendein Geräusch aufgenommen wurde. Konnte es noch nie starten. Wieder gelöscht ### 1/5 — Terribly unreliable *2026-05-03, version 2.7.11* I’m an audio engineer and I know for a fact that a carbon belt would not vibrate at 20,30,40,50,70,80 Hz with subsequent twangs. It must be reading the higher harmonics. ### 1/5 — Pretty much pointless. *2024-08-27, version 2.7.8* 4 plucks of the belt, 90hz,30hz,89hz and 45hz. Cant do anything with that data. ### 1/5 — Frustrating *2024-07-15* Had I know I would have to use this crappy appt app to adjust the belt, I would have stuck with chains. The love affair is over. My finger is sore from so much gd belt plucking and I’m a guitarist. Poor poor poor app. ### 1/5 — Sensitive *2022-08-24, version 2.4* Way to sensitive now for me,spoils a perfectly good app which worked really well 👎👎👎👎 ### 1/5 — Leaves much to be desired *2022-07-30, version 2.3* The app does not have a “record” or measure button. Thus it is unclear when no measurement is recorded whether I’m using the app wrong, if my belt is set wrong, or if there is too much background noise or other problems. I was able to get the app to work one time, but since then have never gotten any measurements recorded. ### 1/5 — stürzt laufend ab *2021-09-19* funktioniert leider nach dem update überhaupt nicht mehr / stürzt ab sobald man den ton mit dem mikro aufnehmen will ... ### 1/5 — Old version much better *2021-09-02, version 2.1* The new update off this app is utter crap they really need to update to older version ### 1/5 — Seit Update ist die App Müll *2021-06-16* Vor dem Update hatten die Messungen einwandfrei funktioniert. Mittlerweile ist die App Müll, funktioniert schlecht, man zupft sich die Finger wund bis ein paar Werte zustande kommen. Das löschen der gemessenen Werte geht nur einzeln und ist aufwändig. Wer bitte braucht den berechneten Mittelwert aus drei Werten ? Da hätten sich die Programmierer besser mal die Arbeit und das Update gespart, den Nutzern hätte das weit mehr genutzt als miserable Updates. Null Sterne wäre korrekt. ## Most praised reviews (10 highest-rated) ### 5/5 — Easy belt tension *2026-06-15, version 2.7.11* Thanks for the free app. Used on cvt v belt and timing belts. Clear instructions now ensure good measurements. ### 5/5 — Funktioniert problemlos mit IPhone 11 *2023-12-28* So einfach wie Gummiband zupfen. Vier Messungen zwischen 45 und 46 Hz. Eine Fehlmessung konnte durch anklicken sofort gelöscht werden. Ergebnis ist im grünen Bereich. ### 5/5 — Frequenz und gemessene Spannung stimmen *2022-03-17* Nachdem ich die Gates Riemen immer manuell gemessen habe, wollte ich nun mal das App ausprobieren und ich muss sagen, dass es besser klappt als erwartet. Sprich, den Riemen mit Spannungsmesser richtig gespannt und anschließend die Frequenz gemessen. Volltreffer: 5 Messungen die jeweils nur 1 Hz auseinander liegen und das natürlich im richtigen Frequenzbereich. Weiter so. Gemessen wurde mit iPhone 12 ### 5/5 — Iphone 7 IOS 14.4.2 *2021-04-05* Die App ist klasse funktioniert bestens. ### 5/5 — Does the job! *2020-06-04, version 1.7.7* This is a good tool if you don’t have access to Gates Krikit gauge or Eco Tension tester. Variations to a degree are to be expected. It is the nature of slight variations in cranks, bb’s, chainrings and sprockets. ### 5/5 — Sehr praktisch *2019-07-29* Top zum Einstellen des Zahnriemens. Genial einfach, hat zwar einen gewissen Spielraum zwischen mehreren Messungen, aber nach einigem Probieren klappt es sehr gut. Bezahlbare Hardware-Lösungen dürfen auch nicht viel genauer sein, deshalb klare Empfehlung! ### 5/5 — Funktioniert *2019-06-21* Keine Abstürze bis jetzt auf dem iPhone 7. Gut reproduzierbare Ergebnisse bei ruhigem Umfeld. Habe es mit dem Eco Tension Tester verglichen. Skala und Hz Werte stimmen gut überein. Der Tension Tester hat eine schief aufgeklebte Skala und wenn sie abfällt ist er wertlos. Der geht zurück, die App bleibt ### 5/5 — Perfect for engine timing belts etc *2018-08-21, version 1.7.3* I use this app regularly when setting tension on timing belts and other automotive drive belts. Very accurate more so than expensive belt frequency instruments. ### 5/5 — Works very well *2016-10-04, version 1.6.1* I have a Scott hybrid bike with a Gates CDN belt drive. This app makes it easy to check the belt tension, and includes guideline tension figures too in case you forget the settings. You "twang" the belt and the app uses the phone's microphone to display a vibrational frequency that corresponds to the tension. The readings are very consistent, and there's a clever auto-sampling function that means you don't have to keep pressing buttons to take repeat readings. Altogether a great app for a specific purpose. ### 5/5 — Great idea! *2016-01-13, version 1.6.1* Got this to check the drive belt tension on my wife's new Gtech bike, and it works well. Simple, quick and effective! --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-27.*