iPhone Screenshots


Pairing the smartphone with the "Forumslader", a bicycle dynamo charger.

Using a bluetooth connection, the Forumslader can be used as a speedometer as well as an altimeter to measure your speed and altitude. It has a high-quality power supply and an easy to use interface to access both operating and internal data.

You may connect additional sensors as well, such as an air pressure sensor (on the circuit) or a thermosensor (external or on the circuit).
The following data can be displayed, evaluated and saved with a connection to your smartphone:

- current speed
- current gradient
- current height
- kilometers travelled
- travel time
- time
- battery charge
- battery power
- used power
- dynamo power
- current
- max./min. gradient and speed (per day and tour)
- travelled height
- last battery capacity
- voltage of every battery cell with an accuracy of 5 mV

The app supports these languages: German, English and Dutch. Other languages can be made available upon request.

Capturing this data is done without a connection to the smartphone and is saved within the Forumslader itself. The Forumslader can store more data than any other device currently available and is built to last.

The radio range of the sender is up to 30 meters, or 1-5 meters when placed in the head tube or the recumbent bike frame tube. If an upgrade for the range is needed, you can add a wireless coupler set with a 25 centimeter cable allowing you to use an external BT-antenna.

The thermosensor is not needed because its usage is only for measuring temperature, but when used it has to be placed in the airstream. The inner temperature of the Forumslader will be measured as well.

For a correct distance computation you must have the correct pole number of the dynamo, as well as the correct tire circumference in millimeters (This may be set under “system”). To get an accurate tire circumference you can use the speedometer or check measured data from a previous ride. The most accurate data is obtainable by recording a long route and comparing your data in relation to the GPS-distance measurement.

Pedal frequency sensors can be integrated too using the “connect to FL” option. When connecting these, ensure your sensor has been turned on. The display must be adjusted to display the pedal frequency or the pulse rate within data fields.

For a unlimited time of using the Hardware, you have to connect the support.

What’s New

Version 2.2

Hey Guys! I'm happy to present you Version 2.2 of the Forumslader App. If you notice any issues or have an feature request, feel free to contact us :)

- New: Option to prevent FL from sleep on supported devices
- Change: iOS 9.3 support is back **UNTESTED**
- Fixed Automatic Daycounter reset
- Fixed some translations
- Fixed some small issues

Ratings and Reviews

5.0 out of 5
1 Rating

1 Rating

Another Ed ,

Excellent compliment to the Forumslader

This makes the already great Forumslader even better!


Sven During
18.7 MB

Requires iOS 9.3 or later. Compatible with iPhone, iPad, and iPod touch.


English, Dutch, German

Age Rating
Rated 4+
© 2019 Sven During


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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