OzVMX Forum
Clubroom => Tech Talk => Topic started by: 090 on January 15, 2010, 09:42:04 pm
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The old boy is hell bent on making a down pipe for the cz360. It has a well functioning GMC side pipe work of art on it now. He just likes the look of a low pipe and wants the challenge of making one . ::) Any hoo... is it legal to put one on?
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NO, it is not legal to put a down pipe on the cz, but it will change the look and the originality.
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I can't see any reason why it would be illegal.
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They put up pipes on cr's in the early days. Most other bikes run the down pipe as well. Dave is there a rule behind your post? As I am after more fact than a personal opinion is all.
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NO, it is not legal to put a down pipe on the cz, but it will change the look and the originality.
Why not, which rule in the GCR's are you refering to ?
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Of course it's legal but please, please try a little harder to talk him out of it Brad. It's not called the sidepiper for nothing.
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2010 manual of motor sport
18.3.0.4
Exhaust
a) May be modified but must generally follow original lines.
b) must be fitted with a silencer.
But I think I have seen pictures of Joel Roberts riding pre 70 CZ's with Down pipes,
and captions indicating he felt the side pipe got in the way of right leg???
picture's of bikes being used in the day should be enough for eligibility
but don't take my word on it
cheers
Noel
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Of course it's legal but please, please try a little harder to talk him out of it Brad. It's not called the sidepiper for nothing.
You are right Firko. I will try and bluff him a bit. I am all for the side pipe bit. I quite like the quirkiness of the whole thing.
Thanks for your input too Noel.
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Of course, the rulebook! We argued this out a few months ago over BigKs Husky pipe. The rule is there for sure but in my 22 years in vintage it's never been seriously enforced. If it had been enforced, 50% of the bikes racing would have had reason to be disqualified. In my opinion rule 18.3.0.4 needs an overhaul. The exhaust rules need to be there to prevent modern fatty pipes and such but to prevent changing a pipe with another period piece is silly.
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downpipes are period.
having seen the bike in question in the flesh,
your old man would want to do a bloody good job... :o
CZ + Downpipe = VMX 8)
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Think back, they ran down pipes on dirt track bikes of all era's and all models so there is no way a downpipe could classed as a non period item. A technical loophole, regardless of whether it follows the original lines or not, it has to be legal ;) I reckon so long as nothing altered beyond repair/restoration then good on your Dad for wanting to have the bike how he reckons it should be..it's all in the eyes of the beholder ;)
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Hallelujah Brother Doc ;D
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brad, as far as pipes there is no rules, there are fellow in usa that put late model pipes on bikes and they look stupid, you will need to curve the way your father is thinking.
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You're a hard man to work out with the way you type things Dave. I can't understand why you make reference to people in the USA putting modern looking pipes on and associating that with me or my father. My father simply wants to put a period looking down pipe on his bike. About the only real argument against it is that it won't be a side pipe any more ( by look ) . I love it the way it is but in the end it's HIS bike so he will do what he wants to do. It seems that there is no real eligibility issue though.
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Brad, no problem at all when you consider the pre'70 TS250 I have has a down pipe instead of an up pipe and it exits stage left instead of stage right..can't be anymore different from the original design but it's perfectly legal due to the fact it's era just like the CZ would be ;)
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My sidepipe fitted with a Bassani down pipe To each his own everybody has their own idea ;D
(http://i48.tinypic.com/15dbwj.jpg)
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Nice! What brand of tank is on it?
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The tank is Alloy Husky 125cc most models had the same tank in the late 70s
My take on what my CZ race bike should look like.
Have seen the Photos of the factory sidepipe CZ runnng down pipes in about 1967
Cheers
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I have been asked a few things like this over the years, I always describe them as "Grey area's"
Depends how anal people want to be on the day.
One thing about doing this with the CZ's though is that the frames are different.
The early frame has the front downtube bend and go underneath the motor where the side cradle tubes bend and join into it.
The later frame has the front down tube straight and finishes just before the bottom of the engine whereby the side cradle tubes go further forward and bend upwards at an angle to meet the donwtube.
What this means is the downpipes on the later frames can fit nicely between the side cradle tubes and so it can tuck up nicely.
On the early frames however that front down tube that bends underneath the engine gets in the way forcing the pipe lower to the ground.
It can be done, I made a pipe like this about 11 years ago but the front section sits about 40 -50mm lower on the sidepipe frames.
I have blown up some of VMX60 photo's to help explain my words.
Early Sidepipe frame
(http://i15.photobucket.com/albums/a393/gmcloa/CZvmx60-1.jpg)
Later 72? onwards frame
(http://i15.photobucket.com/albums/a393/gmcloa/CZvmx60-2.jpg)
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That's interesting Geoff. My thoughts on fitting a downpipe to a 69 360 are purely based on the general perception of what the bike is. The major identifying point of a '69 CZ is its pipe location, hence its "Sidepiper" moniker. It's what defines the bike. While I accept and respect Brads dads right to do whatever he likes with his bike, I'll still take the devils advocate role and argue against it purely on aesthetic grounds.
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Yes Mark, I agree.
That is what defines the model
Funny how everyone want something different to what they have.
I often get calls from guys that want to change their down pipe to an up pipe or change their up pipe to a down pipe.
Even guys with moderns, post 2000 ask me for downpipes :o