I think you may end up getting a late night visit from some of Firko's "associates"...
that's ok, a couple of slaps and then we would be talking bikes and drinking margaritas
Lets take a hypothetical sale of a frame that I sell to you. I say it is a YZ360B frame but the serial number is unreadable but in fact the frame is a MX-B with a MX-A cradle welded in. Now I may not have known that this was the case but in all practical purposes the frame looked and measured identical to my YZ360B so that's why I sell it to you. With your love of Yamaha hybrid bikes and having a SC500 motor spare you decide to combine to two together (and why wouldn't you, it would be a very cool bike) with all other parts being from the pre75 era. I ask you now, as it stand now and to you knowledge (or lack of information about the frame) would this hypothetical bike be legal for pre75?
Using your word that the frame is from a YZ-B I'd have to say yes, but before I stuck the OK sticker, I'd be giving this bike a good old once over because I'd read on the OZVMX forum that the MX-B and YZ-B frames were very similar and that some people had decided to deliberately deceive by disguising the latter frame to look like the former. At the slightest hint that the owner had deliberately set out to deceive by disguising the frame, I'd be forced to send him home without any opportunity to race the bike. Cheating is an offence not taken lightly by this scrutineer.
Now.....methinks you blokes are looking too closely at the what if's rather than building to the rules as they stand. I build extremely trick bikes that verge on the inner edge of the rules but they're %100 legal* because I respect the reasons we have a rulebook in the first place. Rather than building bikes that test the rulebook, why not just build the bike within the available rule constraints. If you look at our rulebook laterally you can build extremely trick bikes without having to verge over to the outer side of the legality edge.
*With the exception of the hubs on my pre 70 Maico which is being addressed.
I think at times we all push the boundaries Firko and cheating is not taken lightly by myself either. As you know I made a bike that was my impression of the Yamaha OW11 (1973) It had mostly 1975/76 parts but the tank was 74 which is a non-performance part. The frame had been modified, as to had the suspension (made to be less than a 1975 model). This made the bike the worse bike in its class but that didn't stop me from butchering a few parts I had to make something that I could still race. That bike complied with all the rules of pre78 and that's where it raced so you won't have any argument from me about cheating.
I think Iain should make this hypothetical bike and he should still turn up to race it at local low key fun meetings in the pre75 class but maybe he should ask his follow races on the line if they are happy with that since they are the ones he is riding against. As he has already said that he doesn't want to race it at national level because he already has fully compliant bikes for both pre75 and pre78.
Which is the worse of many evils? A one year to newer frame that's been altered back a year to become a replica frame or a bike that the only thing that complies to the rules is the frame and the rest is illegal or totally legal but utterly out classed and looking completely different to its competitors and racing in Evo?
Brad, that's a bit rich since I could say the same for you
and it was me who said that it is an Evo bike at the start although if it raced against me in pre75 or pre78 I wouldnt care one way or the other but as eras go it is not an Evo bike but that's where your rules put it not me! Oh and don't forget I did say I wasnt here to try to change the rules but the question was asked if he built the bike would it be legal. You don't want it in pre75 because it isn't legal but you are fine with it in pre78 but those rules state that it isn't legal there either. I know you and I will probably never see eye to eye on this one but please read my last part of the above paragraph (many evils) and sometimes it's not always black and white as I can definitely see your case in point that it is a perfectly fine bike (not legal though) for pre78.