Debuting the RS-GP in the USA after he left the Forward Racing Yamaha set-up during the summer break, Bradl put the machine through its paces in free practice on Friday and finished up 20th overall, two places ahead of new team-mate Alvaro Bautista.
"Pretty good overall," said Bradl when asked to describe his day. "I'm happy with the day we did. It's a new challenge for me. Basically I jump in the cold water because it's a completely new team, a completely new bike. Everything is new. We are starting here in the GP weekend which is obviously not the perfect start for this new project.
"Normally you start with the winter test and have time to work on the bike. We have to adjust everything in a really short time, like position on the bike, like tyres and chassis. This is a lot of work for us but obviously we did a good job today and I'm rea lly pleased with what we have done today.
"The bike is working but still it's a very young bike for MotoGP. There are a lot of things that we have to work on and try. The machine is working in a good way but we want to be faster and better. That will cost a lot of time and work and that's what we're going to do. Also I have to be realistic. We have to make it step by step and not go crazy. We have no pressure and have to work. That's the thing why we are here."
The one-time MotoGP podium man confirmed that he would use this weekend to accustomise himself to the new machine, rather than testing any new parts.
"I first need to get in touch with the bike. To know how it's working and how it reacts when we change something. This will take time. Of course after two or three races we will know more. We know lap-by-lap what we are doing and that's the thing. It's not normal to change team in the middle of the season. So we have to make the best out of it but it seem s we are starting in a good way."
After racing with Honda's seamless gearbox during his three-year stint with LCR Honda, Bradl was well placed to judge Aprilia's transmission, which debuted earlier in the year. The 25-year old confirmed it was one of the machine's stronger points.
"The transmission is working good. I'm really pleased with that. It's working really good, I was surprised. I didn't have the seamless in the previous six months so for me it's a big change in a positive way."
Bradl was forced to sit out his home grand prix in the middle of July after a crash in Assen fractured his right scaphoid. Although capable of riding around the Indianapolis Motor Speedway, the German admitted the injury is still causing some pain under heavy braking and in the quick changes of direction.
"Well, we have to also see my wrist. It's not working one hundred percent. We have to take care to not stress it too much. I have some pain but I think I have it unde r control at the moment. For the race we will see.
"I don't know the bike after some laps. After the half distance I have no idea what is going on. I will just try my best and see where we end up. [In the] Change of direction and basically the hard braking is quite demanding for the wrist."
