Wheel tension app
- A wheel tension balance web tool for master wheel builders -

Wheel truing is an art in its form. Achieving a perfect trueness is satisfying in itself, but after you include recording spoke tension measurements in a wheel building process, a whole new universe opens to a wheel builder. And the very best wheel builders tend to be highly organised and methodical, keeping detailed notes on every wheel they build. That includes measurements for the final spoke tension, which is perhaps the most general measure of any build’s quality. In this regard, a wheel tension app becomes an invaluable tool for a pro wheel builder. This will be an overview article of a newly released tension App, a new total wheel building web app, and an example of how such spoke tension tool can help a wheel builder get better.

What is a wheel tension app?

A wheel tension app basically transforms your spoke tension meter readings into meaningful, useful format of data. Essentially, it provides a wheel builder an easy and fast way to convert your wheel’s spoke tension meter readings into the actual spoke tension (kgF or N). And thus, it gives you a better understanding of what is actually going on tension wise in your wheel. Studying the actual tightness of your spokes will tell you a lot about the quality of the wheel as it may help you diagnose its potential, many times hidden problems.

As such, a spoke tension app is invaluable to many builders, as it provides a quick and easy way to record, present and archive spoke tension measurements.

wheel tension app
App SpokeCalc, a total wheel building web based tool that includes also a wheel tension app.

Compared to WTA, Park Tool’s wheel tension app, SpokeCalc’s Tension App was designed to be used universally and by no means is it spoke tension meter brand specific. To use this total wheel building tool to its full potential, please read my comprehensive article on why spoke tension is so important – Spoke tension - The definitive guide to spoke tensioning. A more detailed instructions manual for the app itself can by logging into the app and navigating to the “Manual” page.

Note: In this article, I am focusing solely on using the app for spoke tension related purposes. An actual scope of the App SpokeCalc, a total wheel building app is actually wider, since it includes also spoke calculator, components editor, storing files and printing summary pages.

Add a spoke tension meter

Let’s start at the beginning. Probably the best thing about this tension app in my opinion is that you can use it with various spoke tension meters.

Before you start using this wheel building app in its full potential, you should add at least one spoke tension meter. Adding a tension meter is easy, just navigate to USER page and click on MY TOOLS tab thereafter. If you haven’t added a tool yet, you should see a button ADD NEW. Enter the tool’s name and that’s it, for now at least.

Note: You can still edit the spoke tension meter’s name later on. Or even erase a tool if you wish so.

add a spoke tension meter to a wheel tension app
Add a tool. Add your tension meter before you start wheelbuilding.

Now that we have a device added, we can move on to creating online spoke tension reference tables for your spoke tension meter.

Spoke tension charts

Many spoke tension meters have detailed tension charts for various spokes already prepared. See for example the notorious Park Tool’s TM-1 scale readings chart. To use it, just navigate through table defining appropriate spoke material, dimension and desired spoke tension in the process.

spoke tension conversion table
A spoke tension chart / tension conversion table for the famous Park Tool's TM1 tension meter.

This document, also called spoke conversion table, contains tension meter readings for reference spoke tensions. Simply said, if your tension meter scale shows you value of 14 once the spoke you are measuring deflects, to which actual spoke tension in kgF does it translate? Does this mean 120kgF or just 80kgF in the actual spoke tension perhaps? Knowing how your tension meter scale correlates with the real tension in kgF will give you an insight to what really is going on with the wheel itself.

And since every spoke deflects differently when you insert it in your spoke tension meter, your scale readings will be different with every spoke dimension and shape. In App SpokeCalc, a total wheel building tool, a user can create and store spoke tension conversion charts for multiple spokes and across multiple tension meters. Write down tension meter readings for reference tension values and periodically check if your tension meter is still precise. Round, bladed, classic or straight pull spokes supported.

In that way, all your spoke tension charts are always available to you online and ready to be modified in the process of spoke tension meter calibration.

save your tension charts
Save all your tension meter conversion tables and use them with the new Tension App!

Make a new spoke tension chart

Creating a new spoke tension table is a straightforward process. If you have a spoke tension chart table available, just like Park Tool’s TM-1 reference table above, just start entering details about the spoke (name and dimension inputs), then select a spoke tension meter for which you will be writing down your spoke tension readings and proceed to “Conversion table” tab.

park tool spoke tension conversion table
Comprehensive tension meter conversion table will help you easily turn readings into real numbers.

To create a spoke tension conversion table, copy your tension meter readings for each reference spoke tension in kgF from the conversion table that was supplied with your tension meter. You don’t have to necessarily fill all the fields; however, the tension app will work at it’s best if it has a complete scale readings data. Now you have your spoke tension conversion table available online and ready for use with the tension app.

park tool spoke tension conversion table
Entering spoke tension meter scale readings for actual reference tension values.

When you are done, just press Save & Preview button, which should store your spoke tension chart in My Files page and redirect you to a summary page (figure below). Since spoke tension charts are supposed to be dynamic files, as spoke tension meter wears down with time, you will also be able to update spoke tension readings on this page at any time. You will find this option invaluable for the process of spoke tension meter calibration which should be done periodically.

spoke tension chart summary page
A summary page – the spoke tension chart that translates how your spoke tension meter scale corresponds to actual spoke tension.

Ok, but what if you don’t have a spoke tension chart already available for your spoke?

Note: At this point, please abandon the idea of searching online for similar tension meter charts and copying the data.

Then, it becomes a little bit complicated as you have to perform a spoke tension meter calibration on its own for which you need a high quality spoke tension calibrating device. Read more about creating spoke tension charts from scratch and spoke tension meter calibration process in my other article, Tension meter calibration - How to calibrate a spoke tension meter and make your own spoke tension chart.

So, now that you have a custom spoke tension chart, it is the right time to finally proceed to the tension app.

Wheel spoke tension app

Once you select your spoke tension meter and the spoke you will be using for taking tension measurements, a corresponding spoke tension chart will be imported to your right side of a screen. Start taking spoke tension readings of your wheel and navigate through your spoke tension chart table, which was previously imported, to see where your spoke tension measurements fall.

tension app import spoke tension chart
A specific spoke tension chart is imported in the sidebar after a desired spoke and a tension meter has been selected.

If you have defined a target spoke tension in the Wheel tab, the tension app will calculate a target tension meter reading for spokes on each side of your wheel based on the spoke tension chart imported. This will be the reference number you are aiming for on your tension meter scale. Target spoke tension of your wheel will also be used to calculate the deviation of a single spoke tension from your target value (for example +11%). With time and practice, you will define more strict maximum positive and negative tolerances for such deviations. And that will surely raise your standards and with it improve the quality of your builds. Smaller the tolerances, the more gouped will be your spoke tension measurements around the average and the more uniform relative spoke tension.

target tension app
A specific spoke tension chart is imported in the sidebar after a desired spoke and a tension meter has been selected.

If you defined your spoke count for each side of a wheel, you should see input fields open up for each spoke in the app section. Once you start entering spoke tension readings of a single spoke, you should see live calculations of an actual single spoke tension, its deviation from your specified target tension and an average tension of all the spokes on one side of a wheel.

tension app calculations
Live calculations of actual spoke tension based on your spoke tension meter readings.

The choice when to start filling spoke tension readings of a single spoke of a wheel into a table below is yours. During the mid-phase of a build it is normal to just use the imported tension chart and calculated target tension meter reading for a reference. I usually start entering values into tension app and take notes almost at the end of the wheel project, to check the quality of a build and archive spoke tension measurements.

On the other hand, a tension app can be very useful for diagnosing existing rim and wheel problems. Sometimes you may want to run numbers in the tension app before starting the wheel truing and tensioning process and inspect the correlation with the overall picture you get compared to how a wheel behaves on your truing stand. On a basis of countless experiences and unexplainable intuition most seasoned wheel builders have a wisdom to quickly notice irregularities in spoke tension across spokes in the wheel. Some builds, may they be reasonably true, are just not worth servicing.

So, you have entered your first data into the tension app, and what now? How to in inspect the wheel tension wise and get a clear picture of actually what’s going on with the wheel?

Analysing and diagnosing the wheel

Look closely to the data and calculations you get by running your spoke tension measurements into the tension app and you will get a clearer picture about spoke tightness and wheel condition. On the summary page you will find a comprehensive statistical analysis of your spoke tension measurements.

diagnosing the wheel tension problems with tension app
A summary page with detailed view of spoke tension on each side of a bike wheel, including line charts.

Instead of comparing left and right side spoke tension measurements, focus only on one side of a wheel at a time. It is a term we call a relative spoke tension. Tightness uniformity of the spokes on one side of the wheel will be measured with the average spoke tension. Get that as close to your specified target spoke tension for that particular side of your wheel. However, you should also aim for a minimum deviation of a single spoke tension from that same target spoke tension value.

Note: try to get every spoke on each side as close to your specified target spoke tension value.

The relative spoke tension will also be noticeable from the smoothness of your line in the visual diagram. The line chart tool, this tension app includes, is also a good base for analysing and diagnosing the spoke tension state of a wheel.

You will quickly notice a problem when a moderately true wheel has one or more spokes deviating significantly from the average tension. Be careful of such spikes in your line chart as they may indicate you be dealing with deformed rim. Moreover, spokes that are relatively loose in regard to the average spoke tension on that side of the wheel tend to be the weakest link as they deflect significantly more during wheel rotation and under load and as such are more prone to breaking.

Unfortunately, in this moment, the tension app’s summary page of spoke tension measurements doesn’t include so called radar chart visual diagrams, which can be a bit easier to interpret, if you follow Park Tool's article about diagnosing the wheel condition.

Final thoughts

Striving to be more methodical and organized as a wheel builder, there are many tools and techniques that will help you make better wheels. Using tension app to record and archive spoke tension measurements in a useful format definitely is a way to improve an overall quality of your builds. Just take time run the numbers in the app and observe spoke tension patterns that may arise in your wheel. It may open your eyes as a wheel builder.

If you are interested in trying the tension app and all its features it encompasses, you can get it now via the link below. Happy wheel building!

Get the tension app

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NEW!!! We've just released a total wheelbuilding tool. Calculate spoke length, save components, calibrate tension meter and use tension app.