I believe regular synthetics have some kind of friction modifier that will cause problems with the plates on your clutch since the R1's use a wet clutch. I could be wrong.

I'd just go with Yamalube 20-40 personally. I'm a pretty big fan of synthetics in cars but it just seems like a big waste of money on bikes. I'd rather change my oil more often and use cheap Yamalube than use synthetic and go for extended intervals. I've heard of guys on R1-forum using Rotella-T (Cheap ass diesel engine oil) and putting some huge amount of miles on their bike and not having problems.