27mm Caliper Pistons RideCBR.com › Forums › General Tech Discussions › 27mm Caliper Pistons This topic contains 0 replies, has 1 voice, and was last updated by ysbytymike 3 years, 1 month ago. Viewing 1 post (of 1 total) Author Posts 12/25/15 at 11:43 am #71353 ysbytymikeRegistered Member Training WheelsPoints: 190 Hi guys / gals. Anybody know the model/s cbr600 that had the twin 27mm pistons? I think they were earlier than the twin 25mm but cannot find when they changed. Cheers Mike Author Posts Viewing 1 post (of 1 total) You must be logged in to reply to this topic.