Biaggi, who was also learning the new revised track layout, ended the day 12th and Kagayama 17th after focussing on detail changes to their machinery, but both aim to be back amongst the top runners tomorrow.
Series leader James Toseland (Honda) posted the day's fastest time, just over a tenth-of-a-second ahead of his nearest rival Noriyuki Haga (Yamaha). Third quickest was Ruben Xaus (Ducati) with reigning champion Troy Bayliss (Ducati) fourth.
Max Biaggi - 12th, 1:40.804:
"This morning we had some settings problems, so we made quite a few changes to the bike for the qualifying session in the afternoon. Then we focussed on sorting out the engine braking and tomorrow we will try and find a good balance to the bike so that I can push hard. I have ridden this track many times in the past, but this is my first time riding the new layout, so there was that to learn as well today."
Yukio Kagayama - 17th, 1:41.273:
"Normally I like Assen and normally it likes me, but today was very strange. I did not find hardly any good grip at all today and I'm not sure exactly why. We made some suspension changes to the bike for the afternoon qualifying, but we had a little bit of a clutch problem and I couldn't push hard. Tomorrow we'll make some more changes to the suspension and see if we can get better grip. We need it!"
Friday WSB Qualifying: 1 Toseland (GB-Honda) 1:39.603, 2 Haga (J-Yamaha) 1:39.750, 3 Xaus (E-Ducati) 1:39.765, 4 Bayliss (Aus-Ducati) 1:39.806, 5 Corser (Aus-Yamaha) 1:39.938, 6 Muggeridge (Aus-Honda) 1:40.092, 7 Nieto (E-Kawasaki) 1:40.201, 8 Smrz (CZ-Ducati) 1:40.355, 9 Lanzi (I-Ducati) 1:40.445, 10 Brookes (Aus-Honda) 1:40.480. 12 Max Biaggi (I-Alstare Suzuki Corona Extra) 1:40.804. 17 Yukio Kagayama (J-Alstare Suzuki Corona Extra) 1:41.273.
Team Alstare Suzuki Corona Extra rider Xavi Simeon finished the first day of qualifying for the Superstock 1000 Championship with ninth place and a bruised right hand and foot - thanks to a crash in the afternoon session.
The Belgian rider crashed at the third turn when his bike spat him off and went to the Clinica Mobile for a check up and X-rays, but fortunately no bones were broken.
Xavier Simeon- 9th, 1: 44.873:
"I am battered and bruised after my crash but I'm strong and I'll be riding tomorrow for sure. I am not sure, but I think the reason for the crash maybe because of a problem with the clutch. In the afternoon I tried to go for a quick lap but I kept running into traffic and I never got a clear track. This is my first time here on a 1000 and it feels very different to what I've ridden before. I'm optimistic that we can improve a lot in tomorrow's sessions and be in good shape for the race on Sunday."
Friday Superstock 1000 Qualifying: 1 Badovini (I-MV) 1:43.192, 2 Corti (I-Yamaha) 1:43.865, 3 Van Keymeulen (B-Yamaha) 1:44.111, 4 Dionisi (I-Suzuki) 1:44.180, 5 Tode (D-Honda) 1:44.303, 6 Pirro (I-Yamaha) 1:44.445. 9 Xavier Simeon (B-Alstare Suzuki Corona Extra) 1:44.873.