# Forumslader

> Bicycle dynamo charger companion app for speed, altitude, and battery monitoring. (iPhone/iPad app by Sven During.)

- Source: https://appshunter.io/ios/app/forumslader/id1231736542 (this page in markdown: same URL + `.md`)
- Developer: [Sven During](https://appshunter.io/developer/1231736541)
- Category: Sports
- Price: Free
- Rating: 5.00/5 from 1 App Store ratings · 2 written reviews indexed
- Age rating: 4+
- Requires: iOS 12.0 · 12 MB
- Languages: American English, Dutch, German (Germany)
- Released: 2017-05-07
- Data updated: 2026-06-25
- Monetization: free
- User reviews in markdown: https://appshunter.io/ios/app/forumslader/id1231736542/reviews.md

## What is Forumslader?

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.

## Key features

- Bluetooth connectivity
- Speedometer and altimeter
- Battery data monitoring
- Support for additional sensors
- Ride data logging and evaluation
- Adjustable display fields

## Recent user reviews (2 of 2)

All indexed reviews: https://appshunter.io/ios/app/forumslader/id1231736542/reviews.md

### 5/5 — Startet nicht mehr... aber sofortiges Folgeupdate half

*2020-11-20, version 3.0.1*

Ursprünglich mit dem ersten Update seit langem (15.11.20) komplett kaputt gemacht. Startete nicht mal. iOS 14.2, iPhone 12 Pro.

Das Tags drauf sofortig erhältiche Reparatur-Update behob das Problem.

### 5/5 — Endlich auch für iOS!

*2020-11-14, version 3.0*

Bin schon länger glücklicher Forumslader Nutzer und sehr froh darüber, daß ich nun alle Vorteile der Bluetooth Variante endlich auch mit meinem iPhone nutzen kann. Danke, daß Ihr die "Schmerzen" der IOS Entwicklung auf Euch genommen habt, um die Schranken des Bergwerks zu überschreiten 😜
Nach wie vor ist der Forumslader die effektivste Methode, um die Energie beim Radfahren in Strom für die elektronischen Begleiter zu verwandeln und damit auch auf längeren Touren energieautark unterwegs sein zu können. Als nettes Schmankerl kann man mit Hilfe dieser App einen Fahrradcomputer ersetzen und hat damit immer den vollen Überblick über die gesammelten Kilometer und die dabei gewonnene Energie. Ein tolles Gesamtpaket, das ich nicht mehr missen mag!

## Frequently asked questions about Forumslader

### What does Forumslader do?

Forumslader pairs with a bicycle dynamo charger via Bluetooth to function as a speedometer and altimeter. It displays and saves data like speed, altitude, distance, and battery status.

### Can Forumslader connect to other sensors?

Yes, Forumslader supports connecting additional sensors such as an air pressure sensor and a thermosensor for more comprehensive data collection.

### What languages does Forumslader support?

Forumslader currently supports German, English, and Dutch. Other languages can be made available upon request.

### How accurate is the data in Forumslader?

For accurate distance computation, you need to set the correct dynamo pole number and tire circumference. The app suggests recording a long route and comparing data with GPS measurements for the most accurate results.

### Does Forumslader have ads?

No, Forumslader does not contain advertisements.

### What devices is Forumslader compatible with?

Forumslader is available for iPhone and iPod devices.

### How often is Forumslader updated?

The latest version, 3.0.5, was released on November 7, 2023. Updates are released periodically to improve functionality and add features.

### What is the user rating for Forumslader?

Forumslader has a high user rating of 5.0 stars based on 1 rating, indicating positive user sentiment.

## Version history (last 5 releases)

### 3.0.5 — 2023-11-07

small bugfixes

### 3.0.4 — 2023-10-20

- Updated for iOS 17

### 3.0.2 — 2021-03-15

Fixed an issue where the FLV6 could not be found.

### 3.0.1 — 2020-11-16

- Fixed a bug which causes the Forumslader 3.0 App to crash, when updating from an older version

### 3.0 — 2020-11-14

I'm happy to present to you the new Version 3.0 of the Forumslader App. This Version includes support for the upcoming Forumslader V6, new functions for Forumslader V5 and much more. If you notice any errors or bugs, feel free to send me an E-Mail :)

New:
- Support for Forumslader V6
- Complete Settings Overhaul
- Added Option to change Dynamo Mode (FLV6)
- Added Option to install Firmware Updates (FLV6)
- Added Option to change shut-down current
- Added improved support for iOS 13+

Improvements:
- Darkmode integration for iOS 13+
- Updated LaunchScreen

Fixes:
- Fixed problems with the layout
- Fixed StatusbarColor
- Fixed some translation

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*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 2026-06-25.*