The composite frame, which turned heads with a pair of four places on its public debut in the hands of wild-card Dani Pedrosa at Misano earlier this month, was first tried by Binder and Red Bull KTM team-mate Jack Miller at the Monday test.
Although tight-lipped afterwards, Miller indicated it had improved grip and, with one eye already on next season, KTM delivered the composite design for Binder and Miller to try in Friday practice.
Binder’s 1m 43.489s not only topped the timesheets but finally broke Jorge Lorenzo’s 2015 lap record, set during the Bridgestone tyre era.
“We used the new chassis today, I was really happy with it,” Binder told MotoGP.com. “I really liked it.
“It definitely helped me on the exit of the corners a little bit. So that was a real positive point that we've been working on to try and solve, and it's one step in the right direction.”
The South African added: “We made some small changes, small updates and each time we went out was better.
“Really happy to finish the day on top, but of course the most important is to go straight through to the Q2 and try and do a good job tomorrow.”
“My team did a great job to give me confidence when pulling the front brake and really trying to stop at the last moment, which was great. And now I have that little bit more hook-up [from the carbon fibre chassis] that I've been looking for.
“Still, we need a little bit more, but I think it's a really good start.”
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Team-mate Miller also felt good on the new frame although he claimed direct Qualifying 2 access with tenth place (+0.7s), after being forced to switch over to his ‘old’ bike (using the steel trellis frame) after a fall.
Red Bull KTM team manager Francesco Guidotti said: “Jack made a comparison this morning, first run with old [chassis] and then the new bike. He felt immediately something better on rear grip. In general, he felt more comfortable.
“We brought this new chassis just to have more feedback for the last part of the season, [to prepare] for next year. At the moment there’s a big chance of racing with it. Let’s wait for this practice and then make a decision.
“Our main target now is next year’s championship of course. We are working hard for it. We are trying to get as much as [development as] possible from the last part of this season. Because the Valencia test is weird, only one day, low temperatures.”
Binder is fourth in the world championship and the top non-Ducati rider, but 100 points behind Francesco Bagnaia.