Direct-drive sim racing wheel

The first commercially broadly available direct-drive wheel base was released in 2013 by the UK-based Leo Bodnar Electronics, after having been retailing to racing teams and professional centers since 2008.

[7] It was followed in 2015 by the US-based SimXperience AccuForce V1, and by the first do-it-yourself open-source hardware OpenSimwheel or "OSW" kits for users with good technical knowledge.

[8] Simucube was one of the manufacturers who previously provided Open Sim Wheel kits, and is a brand name owned by the Finnish manufacturer Granite Devices, which also supplies driver electronics for controlling servomotors and stepper motors, both for sim racing and industrial use.

Granite Devices started as a hobby project by the Finn Kontkanen Tero when he was building a CNC milling machine, and realised that there was many alternating current servomotors of high quality on the market, but that driver electronics for controlling such motors was expensive or hard to come by.

[9] Issues, quality, and performance indicators of direct-drive wheels, and of sim racing wheels in general, include detail and fidelity of force feedback, smooth torque transmission, nearly-zero backlash, rotary encoder resolution, clipping, dynamic range, torque ripple,[2] cogging torque,[10] drivers and digital signal processing with control electronics,[2][11] signal filtering,[8] backdrive friction,[10][12] low inertia,[12] damping,[12] fast response, precise positioning, electromagnetic interference,[13] and latency.

[23] The static force reduction filter introduced with Simucube 2 wheelbase allowed to address this issue while keeping a fully linear signal.

A side-effect of this filter however is that while turning the wheel one feels a weakening of the FFB signal, which some drivers might dislike.

[23][27] Similarly, the slew rate reduction filter reduces or dampens sudden acceleration spikes in FFB torque, due for example to hitting kerbs or bumps.

However, the stronger motors will often have a faster slew rate (the time an amplifier takes to respond to a signal) which gives better steering response and more realism.

Some quick releases have (often proprietary) integrated contact pins for transferring power and data to buttons and displays on the wheel, but these usually do not work across manufacturers.

A de facto industry standard among sim wheels, which again stems from a widely used mechanical industry standard, is a front mount with a bolt circle measuring 4×130 mm diameter and metric M8 screws, which means that four screws are evenly placed along a circle measuring 130 mm in diameter.