Article snapshot taken from Wikipedia with creative commons attribution-sharealike license.
Give it a read and then ask your questions in the chat.
We can research this topic together.
The stadium has hosted the final of both the Speedway World Team Cup in 1995 and the Speedway World Cup in 2014. It has also hosted 16 Speedway Grand Prix events including the final of the 2008 season which was actually run as the FIM Final Speedway Grand Prix. The final was to be the Speedway Grand Prix of Germany and held at the Veltins-Arena in Gelsenkirchen, however the FIM deemed that track to be unsafe due to the inclement weather (despite the Veltins-Arena sporting a retractable roof which was closed at the time the track was laid) and the GP was re-staged a week later in Bydgoszcz.
The speedway track at the stadium is 348 metres (381 yards) in length. Tomasz Gollob is the track record holder with 60.11 seconds for a 4 lap race with a clutch start. Gollob set his time on 20 June 1999.
* Event re-staged in Bydgoszcz due to FIM ruling the track at the Veltins-Arena in Gelsenkirchen, Germany was unsafe due to bad weather. As it was run in Poland it was renamed the "FIM Final Speedway Grand Prix".