RoadCar wrote:Well a 400 is more expensive to run than a 200/250 plus I am still restricted to 33bhp.
Honda claimed around 37 PS for the CB400/4 and the twin's about the same, maybe a tad less. Those figures at the crank on a brand new bike, carefully set-up and with new chains etc etc.
The 33 bhp limit does not say where it is taken from so can quite reliably be assumed to be power as it reaches the ground.
Having seen other bikes on dyno's I'd be very surprised if any 70's 400 cc bike made as much as a genuine 33 BHP at the wheel. more like 30 bhp...
To put that into some perspective, the 12,000 rpm CB125T was claimed to make 17 BHP. A carefully tuned race bike based on that engine made 13 BHP at 13,000 rpm. If a 17 bhp 125 can lose 4 bhp between honda's 'P'S' at the flywheel' and BHP at the dyno's roller, I very much doubt a 37 p.s. bike will lose LESS than the same 4 BHP.
Another example...a late model XR250 was reckoned by Honda to be good for 30 BHP. On a rolling road, they typically make around 21 BHP.