These models are available in two different frame options. A carbon front end combined with a 6061 aluminium rear end, or a more budget-friendly all-aluminium chassis. These models are available in two different frame options. A carbon front end combined with a 6061 aluminium rear end, or a more budget-friendly all-aluminium chassis. These models are available in two different frame options. A carbon front end combined with a 6061 aluminium rear end, or a more budget-friendly all-aluminium chassis.