Author Topic: 79 CR250 Front End Conversion  (Read 72570 times)

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Offline Digga

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Re: 79 CR250 Front End Conversion
« Reply #45 on: July 02, 2014, 12:34:52 pm »
Surely 10 years ago the Author of the rules could have come out and quite simply said " hey guys, you don't have to just use EVO forks, you can also use Pre 85 forks , pre 85 air cooled motors etc" instead of making it public a couple of months ago, 10 years after the fact

Who was, or is, the Author & custodian of the EVO rules & where/when was this interpretation made public a couple of months ago? I would like to see the actual comments so I can read them first hand for myself please :)
1977 Yamaha YZ250D, 1977 Yamaha YZ400D, 1980 Yamaha YZ125G

Offline marshallmech

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Re: 79 CR250 Front End Conversion
« Reply #46 on: July 02, 2014, 10:07:04 pm »
Shane i do feel strongly about it that why i asked the question its not that hard really is it all that's needed is for it to be officially said they are or are not legal is that so hard.
And to Super this forum is a place for people to ask questions and to learn from others i asked a question because i read the rule one way others read it another way, I'm not saying anyone s cheating i simply wanted some clarification on the rule because as shown on here a rule should not be able to be interpreted  by the way it is read it needs to be plain and simple and understandable to one and all if it was all this discussion would not be here and we could do as the rule says.
As for people not attending the Evo class could be  because of  this reason so many believe you have to use forks from an evo bike and other say you don't and so wants to go to a title when unsure of how the way the rules read.
And just a footnote jim elis, tommy croft, marty smith all ran the production forks on there works bikes in the stadium races back in the day only jim pomeroy ran the works forks so could they be that bad when the best guys had access to works parts and for that matter the best parts money could by and they ran the production forks makes you wonder what all the fuss is about !!!!!
Andy Viper #70
Honda CR125 RB
Honda CR125RC
Honda CR125RA
Honda CR250RZ
Honda Z50A

Offline marshallmech

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Re: 79 CR250 Front End Conversion
« Reply #47 on: July 02, 2014, 10:36:59 pm »
Oh and one more thing a few years ago a guy riding in the pre78 125 class on a Suzuki he  was protested because he had the top triple clamp from a 1 year later bike i  gather it was from a evo class bike the protest was upheld and he lost his 3rd position if i recall all because the top[ triple had rubber bar mounts and wasn't from a pre 78 bike  where is the difference if i used pre 85 forks on my evo bike the triples are later stuff and going by the above example it would be illegal.
As i said it needs to be black and white not able to be read in different ways.
And this is IMO why people stay away its allot of time and expense to get to a title meeting and not knowing if your bike is right from a few peoples interpretation of the rules compared to some others  is a big deterrent. Just my thoughts now I,m off to get my bikes ready for a Viper meeting. Hopefully with this discussion some firm official judgment of the rule will come. 
 
Andy Viper #70
Honda CR125 RB
Honda CR125RC
Honda CR125RA
Honda CR250RZ
Honda Z50A

Offline William Doe

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Re: 79 CR250 Front End Conversion
« Reply #48 on: July 02, 2014, 11:28:27 pm »
Oh and one more thing a few years ago a guy riding in the pre78 125 class on a Suzuki he  was protested because he had the top triple clamp from a 1 year later bike i  gather it was from a evo class bike the protest was upheld and he lost his 3rd position if i recall all because the top[ triple had rubber bar mounts and wasn't from a pre 78 bike where is the difference if i used pre 85 forks on my evo bike the triples are later stuff and going by the above example it would be illegal.
As i said it needs to be black and white not able to be read in different ways.
And this is IMO why people stay away its allot of time and expense to get to a title meeting and not knowing if your bike is right from a few peoples interpretation of the rules compared to some others  is a big deterrent. Just my thoughts now I,m off to get my bikes ready for a Viper meeting. Hopefully with this discussion some firm official judgment of the rule will come. 
 

This old chestnut gets dragged up occasionally just like the CZ riveted hub scenario  ::) To clarify that protested bike was running 78 model forks with longer travel than the 77 forks not just a top clamp and a Thor arm with longer shocks there were also 2 C model 125s running in the class with alloy B tanks that were also protested. I raced that class at that Nats but withdrew to concentrate on other classes as I could see the shit was gonna hit the fan .
He had raced at previous nats I remember the bike at the Coffs nats where I raced against it . The owner is a nice bloke and it sucked what went down and the protester took no pleasure in protesting that and the other 2 thinly disguised 78 C models with alloy B tanks .
That should have all been cleared up years before as it had been pointed out to officials , but the std reply was if you think its wrong put up your money and protest it .

This is where the system falls down IMHO , some officials are happy to wear the big hat but don't want to tackle head on what can be an ugly situation when a bike is challenged. I think this is slowly improving but those 3 bikes had run at a number of events I had raced at in pre 78 without challenge so it becomes accepted that they are legal until someone puts up the money  ::)
Its only old bike racing FFS get over yourselves





The Artist formerly known as TM Bill

Offline FourstrokeForever

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Re: 79 CR250 Front End Conversion
« Reply #49 on: July 03, 2014, 11:11:19 am »
"This is where the system falls down IMHO , some officials are happy to wear the big hat but don't want to tackle head on what can be an ugly situation when a bike is challenged. I think this is slowly improving but those 3 bikes had run at a number of events I had raced at in pre 78 without challenge so it becomes accepted that they are legal until someone puts up the money  ::)"

Exactly Bill. It all comes down to who wants to pay the money to protest.

Just as a matter of course.....I have a CR250RZ with 43mm Showas on it. That is how I chose to build my interpretation of a RC replica. Does it make me any faster? I doubt it. Why did I do it? Because knowing the Yamaha TLS front end had been deemed legal and some CR guys run them, I wanted my Honda to be all Honda, even though the OEM Showa fork wasn't available in 1979. Neither was the TLS Yamaha fork. Nothing more, nothing less.

 As far as I see it, there is no technological advantage of the Showa fork over the Kayaba. I would of loved to afford a set of 40mm Fox Factory Forks (which are legal) but I had to draw the financial line somewhere.
Then knowing that my chosen front end was (is) illegal for the Evolution class, I chose not to A; alter my bike to be legal, And B; to leave my CR as a shed queen, start it up every now and then and just look at it.

Rules are rules and I do my best to abide by them when it comes to VMX. I had my say when Nathan S asked for help from those interested in proposing a set of rule "tweaks" for next year. What comes of the rule change proposal is anybodies guess but I say, if the Yamaha fork continues to be legal on CR's, then I see no reason why the Showa 43mm fork shouldn't be deemed legal. It is, afterall, only being deemed Illegal purely because of date of manufacture, not because of any technological advantage! 

Hopefully there will be some clarification with any rule change(s), but until then, my CR will stay unused. Shame really, because it is one very sweet looking ride.....
Arrogance.....A way of life for the those that having nothing further to learn.

Offline Digga

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Re: 79 CR250 Front End Conversion
« Reply #50 on: July 03, 2014, 11:54:24 am »
Doesnt really effect me as my only evo bike is 100% original but seems logical that if these changes are deemed incorrect (dont like the term illegal, sounds a bit too serious for old guys on old bikes), then there are 2 options:

1) replace the later model added component/s for racing at all levels with the original ones, or lower if unavailable (e.g. go back a year or more)

2) keep the modified bike as is with the later model added component/s if you so choose and race pre-85

seems to be a common theme that these modifications are not there to improve bike or rider performance etc etc so why do it?
1977 Yamaha YZ250D, 1977 Yamaha YZ400D, 1980 Yamaha YZ125G

Offline FourstrokeForever

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Re: 79 CR250 Front End Conversion
« Reply #51 on: July 03, 2014, 12:34:58 pm »
Doesnt really effect me as my only evo bike is 100% original but seems logical that if these changes are deemed incorrect (dont like the term illegal, sounds a bit too serious for old guys on old bikes), then there are 2 options:

1) replace the later model added component/s for racing at all levels with the original ones, or lower if unavailable (e.g. go back a year or more)

2) keep the modified bike as is with the later model added component/s if you so choose and race pre-85

seems to be a common theme that these modifications are not there to improve bike or rider performance etc etc so why do it?

I did it because that's how I wanted to build MY bike. I didn't build it with the intention of racing but then I started to get the itch to fire it in anger.....Yes, I could change the front end to meet the criteria for Evo BUT I chose not to as it is the only Post Classic bike I have at the moment and I can't see myself spending all the time, effort and money to get 6 races out of 1 bike for a "title" meeting. If my club lets me ride it as it is, I will get it dirty eventually  ;D
Arrogance.....A way of life for the those that having nothing further to learn.

Offline Shane W

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Re: 79 CR250 Front End Conversion
« Reply #52 on: July 03, 2014, 01:26:56 pm »
"This is where the system falls down IMHO , some officials are happy to wear the big hat but don't want to tackle head on what can be an ugly situation when a bike is challenged. I think this is slowly improving but those 3 bikes had run at a number of events I had raced at in pre 78 without challenge so it becomes accepted that they are legal until someone puts up the money  ::)"

Exactly Bill. It all comes down to who wants to pay the money to protest.

Just as a matter of course.....I have a CR250RZ with 43mm Showas on it. That is how I chose to build my interpretation of a RC replica. Does it make me any faster? I doubt it. Why did I do it? Because knowing the Yamaha TLS front end had been deemed legal and some CR guys run them, I wanted my Honda to be all Honda, even though the OEM Showa fork wasn't available in 1979. Neither was the TLS Yamaha fork. Nothing more, nothing less.

 As far as I see it, there is no technological advantage of the Showa fork over the Kayaba. I would of loved to afford a set of 40mm Fox Factory Forks (which are legal) but I had to draw the financial line somewhere.
Then knowing that my chosen front end was (is) illegal for the Evolution class, I chose not to A; alter my bike to be legal, And B; to leave my CR as a shed queen, start it up every now and then and just look at it.

Rules are rules and I do my best to abide by them when it comes to VMX. I had my say when Nathan S asked for help from those interested in proposing a set of rule "tweaks" for next year. What comes of the rule change proposal is anybodies guess but I say, if the Yamaha fork continues to be legal on CR's, then I see no reason why the Showa 43mm fork shouldn't be deemed legal. It is, afterall, only being deemed Illegal purely because of date of manufacture, not because of any technological advantage! 

Hopefully there will be some clarification with any rule change(s), but until then, my CR will stay unused. Shame really, because it is one very sweet looking ride.....

TBM old mate you will have to leave the forum as that is just way to logical thinking for one here.

Offline micks

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« Last Edit: July 03, 2014, 01:55:20 pm by micks »

Offline bishboy

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Re: 79 CR250 Front End Conversion
« Reply #54 on: July 03, 2014, 04:39:48 pm »
maybe next year`s rules http://www.ma.org.au/fileadmin/user_upload/Documents/MOMS/2014_MoMS_Files/Minutes_-_May/2015_Ch_16_CMX_CDT_proposed_changes_in_RED.pdf go to evolution class page 12

So reading that it would imply that any drum brake front end would be ok, on the basis that any disc brake front end would have to have the forks modified or any of those abhorrent twinshock conversions.  Any carby in ok?

And I sold my 82 YZ490 fork recently thinking they wouldn't be legal  >:(

Offline sleepy

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Re: 79 CR250 Front End Conversion
« Reply #55 on: July 03, 2014, 06:10:02 pm »
I read the proposed rule and I'm even more confused. Good to get rid of the OEM bit but still not clear. Does it mean that any drum brake, any air cooled engine and any twinshock frame. Sound like a bit of a free for all.
Had better sell my 81 Maico before it becomes obsolete with all it's stock parts.

Offline Ted

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Re: 79 CR250 Front End Conversion
« Reply #56 on: July 03, 2014, 06:26:36 pm »
Do you guys realise what can happen when the letters OEM are removed from the rule book?

Once it is removed who would bother with 43mm damper rod forks when you would be well within your rights to instruct your suspension supplier to supply you with a current 48mm upside down cartridge fork with fittings to adapt to your backing plate. And you wouldn't have to do that either. You could get a machinist to make you a new twin shoed brake hub to fit your new 48mm fork.

You are not converting anything to fit, you are making / buying new parts.

The author has stated Evo has no era or period ( even though when he wrote the rules he said period flat slide carburettors can be used ) so making / buying new parts has to be allowed.

As there is no era or period for Evo, once OEM is removed from the rules it is open slather to build bikes even the factories wouldn't / couldn't have built back when these bikes were new.

Hardly vintage moto cross.


81 YZ 465 H   77 RM 125 B

Offline sleepy

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Re: 79 CR250 Front End Conversion
« Reply #57 on: July 03, 2014, 08:17:59 pm »
An era or period is defined in this case by a technology piont. Which would be the H for Yamaha and whatever year the TS ended for others. It would be simple enough to say that all parts must have come from an EVO bike or been available for an EVO bike. That of course would kill off the J Yam forks and brake and anyother hybrid using parts from later technology bikes.

If the majority of EVO riders want a free for all (or the opposite) then the rules should reflect that but unfortunaley the wheels of power turn in a mysterious way.
Perhaps a genuine pole should be undertaken of all the EVO rider and not just the vocal minority.

Offline vandy010

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Re: 79 CR250 Front End Conversion
« Reply #58 on: July 03, 2014, 08:28:45 pm »
this is really interesting in that we hear it quite a lot that we're "over regulated"
yet here is a simple set of guidelines that allows us a few freedoms (in the shed and wallet to build something a bit out of the ordinary and then we get to go and have some fun with it) and there's still a few screams from the balcony "we want more regulation"
the rule books always change from time to time, some get it easier and some have to adjust.
evo is a pretty good thing i reckon
 
"flat bickie"

Offline Ted

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Re: 79 CR250 Front End Conversion
« Reply #59 on: July 03, 2014, 08:41:41 pm »
Evo is a great thing as we know it.

If you want to build a hot rod whatever I'm sure your local MX club will let you ride

Mick, using major components manufactured tomorrow is not vintage moto cross.
81 YZ 465 H   77 RM 125 B