If you're new to sim racing and wondered what exactly a direct drive steering wheel is, then this article should help clear things up.
A real car typically has a physical connection between the steering wheel and the front wheels of the car. This means that there's some sort of mechanical system between the wheels and the steering wheel that allows the driver to control the car and as a result of this mechanical connection, feel all the forces transmitted from the front wheels through the steering.
These forces help the driver feel a loss of grip, driving over uneven surfaces, hitting an object etc. Force feedback in sim racing attempts to recreate these forces as close as possible to help the driver feel exactly what the car is doing.
Gear-driven steering wheels
This is normally an entry level type of force feedback steering. Force feedback is applied by using a powerful electric motor that connects to the steering wheel via mechanical gears. This is typical of the Logitech G series wheels like the G27 and G29. The forces are quite strong but there's some delay due to the use of mechanical gears and lots of finer detail isn't passed on to the driver. However, this type of wheel is still very good value and perfect for the beginner sim racer. A Logitech G29 system costs around $300-$400 including pedals.
Belt driven steering wheels
This is what we consider an intermediate type of steering wheel with forces being applied to the steering from a strong electrical motor via a belt. Some of the Thrustmaster wheels (T248) and entry level Fanatec wheel bases (CSL Elite Wheel Base) are belt driven and provide very high levels of force with relatively good fine detail.
These are ideal wheels for the experienced sim racer that wants a good all round wheel base that comes in at a relatively affordable price. The Thrustmaster T248 costs $400 including pedals.
Direct Drive steering wheels
Unlike the previous two systems, a direct drive system is normally sold as a separate wheel base with several steering wheel types that can be bought separately. The wheel base is a actually a very, very power motor that has the steering wheel connected directly to the center shaft of the motor. This direct connection is the reason for the name as well as what makes it so effective.
There's no delay with forces being transmitted to the driver since there's no belt or mechanical gears. Also, the forces are exceptionally powerful and can rival the forces felt in your real road car. Fine details as well as massive jolts are all transmitted instantaneously to give the driver an incredible sense of immersion and the allows for early detection of the car losing grip or sudden snaps of oversteer.
These type of wheelbases have normally been very expensive but have dropping in price recently due to the huge demand. Fanatec's CSL DD wheel base costs €350 excluding steering wheel and pedals. These systems are recommended for the serious sim racer that wants to compete at the highest level.
Conclusion
Direct drive steering wheel systems represent the pinnacle for sim racers. These systems give you the sensation of being in control of a real car and help you not only find that last bit of pace but can make you more consistent as well. If you can afford it, then we highly recommend that you consider upgrading to a direct drive steering wheel system.