In our earlier round of discussions many months ago, ACE, I raised the question (which I am tossing in to the ring again now) as to whether , once a production head has been hand ported, it could be translated into a CNC template to simplify future head work: Even if a rough gouge out could be done by robot it seems to me there may be economies possible by doing that and fine tuning by hand to smooth out surfaces and perhaps even some bench test refining of the partially CNC carved heads. I am not sure who owns the guinea pig bike and whether they see their's as a labour of love for the commuity. Maybe , they could receive a small "royalty" for subsequent buyers that benefit from their groundbreaking costs. Possibly even could be a head port option A and B : Hand ported vs Machine copy without further refinement offered as two different levels of cost. If you remember, we discussed the possibility of a head exchange program where you send in your stock head and receive in return a ported and revalved head. If the project flies, you would need an inventory of at least one head to get it rolling.
72 is short, but 75 doesn't sound like much more, yet all G5s I know of are rock solid. There's got to be more to it on the C5. Though if they're making the special it seems RE hasn't figured out exactly what the issue is. If they had I would have expected a more minor tweak to the existing bike. Scott
Scot :Sorry if this shows up twice: A post I just did seems to have vanished in cyperspace. This idea may be really stupid, but , if it were possible to spin the existing fork lowers on C5 to point the offsets backward instead of forward (KIDS DO NOT TRY THIS AT HOME WITHOUT THE ADVICE OF A QUALIFIED MECHANIC AND THIS AUTHOR DISCLAIMS ALL RESPONIBILITY FOR LOSS OR DAMMAGES RESULTING FROM ATTEMPTING THIS ) then that would increase the trail from 72 to 132 or 6.378 inches (since neutralizing the offset added 30 mm trail, reversing it should add 60 mm) which, if lack of trail were the problem, oughta fix the wobble. I have no idea if it is possible or safe to do this. Just thinking out loud and I mention it only because you were contemplating the feesibility of changing out your fork lowers for the new ones but concluded they were different diameter so couldn't..
I would think that unless the steering neck angle is changed, any offset change would not amount to anything. It is that angle that decides the rake, or so me thinks.