road racing u can't go wrong with any bike as they all have something to offer, wether it be heavier for more reliablity or more power and lighter with less reliabilty.
now i raced mx for 9years and the thing i can tell u is stay away from heavy bikes, they just don't work on a mx track! especially cornering and jumping u will curse urself with the heavier bike. the 4stroke are imho a lot more noticbaly heavier on the top end and that effect ur cornering in the dirt. and the 2strokes are amazing bikes and offer the same power at a lower displacement but they take a little getting used to and some extra care and maintenance.
i would recommend (since ur coming off fast bikes already) that u go with a 250cc 2stroke or 4stroke if u going primary dirt rider. but if ur going to do more road racing then i say go 450cc 4stroke cause ur going to want more power on the road and u can use a 450cc 4stroke in the dirt pretty easy although it'll be rough the first couple times out.
my advice is when u go to the mx track, find out were all the riders take their little brakes as their cooling down before they back on the track and just talk to them about the track. also the first 3 laps just take it easy and cruise around the tack (i.e. walk the track first)
and if ur having trouble on a corner or u can't do a jump, sit next the the corner and watch how others go through the section (body position, were they brake, were they get back on the corner...ect)
and if u want to know how fast u have to do a jump, sit at the side and watch everyone jump, find someone who is constantly clearing the jump and get right on his ass and try to pass him as he's doing the jump, guaranteed to clear it!
i can't offer much advice on road racing a sm, but others can.
if u need any help with the mx part, send me a pm or post up questions ill help u out as best i can
1993 Cr500r
educatio est omnium efficacissima forma rebellionis!
levels of insaity:
1 - talks to self 2 - argues with self 3 - loses argument with self 4 - is no longer speaking to self