Carbon Drive Belt Tension Tool

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.

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.

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.

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.

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.

Plucking the belt I get anything between 39 and 87 at the same spot. Obviously not a reliable way to measure tension.

iOS 14.3. App needs updating. Useless now.

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.

Please update to cover the 174T belt with smaller 4bolt pulleys now being put on tandems. Thx

Dark blue text on a dark background is really hard to read. Should have clear images or short video showing exactly where to hold and how to pluck belt. Feels like it was designed by engineers and for people who already know what they are doing, not for the first time user.