Aston Martin chief technical officer Andrew Green has explained the team would have needed to "define a chassis" quicker than Mercedes if it had wanted to take more transferable components for Mercedes for the coming season.
The components of an F1 car are divided into three categories; listed team components [LTC], transferable components [TRC] and standard supply components [SSC].
Listed team components are “components whose design, manufacture and intellectual property is owned and/or controlled by a single competitor or its agents on an exclusive basis”.
In the case of transferable components, as the name may suggest, these are parts that teams can sell to other teams.
Such components include the gearbox, front and rear suspension, the electrical loom, exhaust system and many other items.
For the coming season, Aston Martin has taken the gearbox and rear suspension from Mercedes.
Explaining why the team did not acquire further components, Green explained: "The reason for the effective rear-end from Mercedes, it comes in a nice neat package, it is aligned.
"We have been through just buying the gearbox and putting our own suspension on it and the two fighting each other for too long, it seemed the right thing to do was to have the suspension on the gearbox that the gearbox has been designed for. It really was as simple as that.
"We tried to have as much freedom everywhere else.
"If we looked at the other areas, the front suspension is one, we could have gone front suspension but then you are into trying to align the chassis into a suspension system that you get late, you have to wait for the suspension to be defined before defining your own chassis and that just wasn't something we could really consider, especially with the timeframes we have.
"We would then be looking at we would have to define a chassis quicker than Mercedes because we would get the information later than them and we are not in a position to do that so that is the reason."