no problem. the 10-15 minute warmup period is also essential in my book....
btw there is a teacher at yoga in the pearl who wrote a book on yoga for cyclists and she also teaches a cyclist-specific class (she is an avid rider herself). i'm sure there are other yoga-for-cyclist classes around town (yoga in the pearl is a little on the spendy side).
as for bike positioning, spending $100 or so on a professional bike fit is well worth the money. i went to dimitri at veloce on hawthorne and he did a great job - i was having some knee pain issues that dissolved after a few months of riding w/his setup. been comfortable ever since.