Complex sentence: Suzuki produced the RE5 between 1974 to 1976, but a few years earlier in Birmingham, BSA's research engineer, David Garside, was developing a twin-rotor Wankel motorcycle.
Split into simpler sentences: Suzuki produced the RE5 between 1974 to 1976. A little earlier, BSA's research engineer, David Garside, was developing a twin-rotor Wankel motorcycle.