SYN. is good oil, but the problem I have found with it you have a wet clutch until the oil warms up. So I've gone back conv. oil & haven't had any more trouble. Haven't tried it in the CBR yet so I can't say anything on that. On my other bikes it did Shadow 1100, Gsx 450 & CRF150. So I just stick with conv. & as long as I change my oil regular intervals I don't have any problems. So on that note it's up to you or maybe some of these other guys will let ya know on the syn. for the CBR.