USB Adapter Support

CompuTrainer™ and Velotron™ are both “serial devices” designed to communicate to the computer via a serial port. CompuTrainer™ was originally released having a 25-pin serial port, and then later a 9-pin serial port.

As serial ports began disappearing from computers and USB became dominant, RacerMate began using USB to Serial adapters – retaining the 9-pin adapter as well. Initially Prolific-based USB adapters were used and a shift was made to FTDI-based adapters due to poor support (from Prolic) for Windows™ Vista. FTDI was then commissioned to design an adapter specifically for our needs – eliminating the 9-pin adapter. This adapter is still in production.

You can go here to see a visual history or click on links below to see pictures of the various adapters to figure out which adapter you may have.


Prolific-based USB adapters


The Bafo USB to Serial adapter was black and had a removable USB cable. It was in-use for only about 1 year and was replaced due to the product being discontinued by Bafo.


The Sewell USB to Serial Adapter was standard on CompuTrainer™ for about 4 years. It is recognized by the blue housing marked with the words SEWELL.


The Belkin USB to Serial Adapter was standard on Velotron™ for about 4 years until we moved to FTDI adapters. It is recognized by the hockey-puck shape and having detachable cables and power supply.

Prolific Drivers

The drivers shown below may NOT be the latest Sewell/Prolific. They are the drivers we have found to be the most stable when used with CompuTrainer or Velotron™.

If you have a computer running Windows™ Vista, Windows™ 7 (any version), or Windows™ 8, and you have a Prolific-based USB adapter, we highly recommend upgrading to the current FTDI-based adapters. No drivers have been found for the Prolific-based adapters that work correctly with CompuTrainer or Velotron.

If you have 32-bit Windows™ Vista and use the Sewell adapter, and have the operating system set to automatic updates, the operating system may update drivers without you knowing — thus replacing the working drivers with “newer” non-working drivers; in which case you must reinstall the older drivers again, by force.

Instructions: Unzip the files into a Sewell folder you create and using the driver update wizard in Device Manager, point the driver update to the location where these file reside.

Windows™ XP (zip file)

Windows™ Vista (zip file) (64-bit Vista, Windows™ 7, and Windows™ 8 users should NOT use the Prolific-based adapter)

FTDI-based USB adapters

An FTDI-based adapter has been standard with CompuTrainer beginning in December 2008, at which point all in-house support for the Sewell adapter was suspended – except as noted above. The first FTDI USB-to-Serial adapter is recognized by the tan and blue housing with blue lights flashing when in use. The custom FTDI-based adapter, which now ships with all new CompuTrainers began shipping as of January 2009. It is recommended when any upgrade is made to include the RacerMate One software.

This driver executable is the same for all operating systems and will correctly detect and install the driver for the operating system you have.

Approved FTDI-based USB Drivers

This driver is the same for all FTDI adapters

Approved Windows™ FTDI Driver

Note: Beginning with Windows™ 7, FTDI drivers are part of the drivers supplied with the Windows™ operating system and from Windows™ Update.


Have any questions?