Author Topic: 79 CR250 Front End Conversion  (Read 72427 times)

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Offline FourstrokeForever

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Re: 79 CR250 Front End Conversion
« Reply #225 on: July 08, 2014, 12:22:17 pm »
They are tougher, offer more flex and are easier on your arms, or so the sales pitch says. Real or placebo, who knows? Almost everything is a performance gain if you apply the same reasoning as those who want the rules changed. I don't give one iota about that though, they just look wrong on a VMX bike as do black rims & gobs of CNC machined billet alloy. Just my opinion like the opinion that others hold as to the legality of CR480 forks (which by the way are & always have been legal). Anyone get it yet?
K

I agree Mick. Taper bars not only look totally out of place on an Evo machine, but they have been tested and proven by bike mags (I can't recall which one I read) do indeed offer less vibration because of the extra flex that is inherent to the style. Less vibration = less fatigue on the rider. Not that I really give a toss about the performance aspect, I just think they have no place on VMX bikes as they alter the "vintage" look of the bike.

Fair dinkum Ted....you'd point holes in a donut! And to all the others who have followed on with Ted and his ridiculous mindless arguments and interpretations, have you even read the proposed set of rules?

I went to the effort of attempting to have a set of rules without any ambiguity as to what is and what isn't allowed in Evolution class racing. I even asked for the discussion to remain positive and to ad suggestions. Seems there is no keeping some people happy even though they agree the rules are very open to various interpretations.

Here are the proposed rules again. Amendments are highlighted in RED

1) Frame must be of ORIGINAL Manufacture twin shock design. Yamaha non linkage "monoshock" design is allowed. After market twin shock Replica era frames are allowed.
1b) NO re-engineering of linkage design frames converted to twin rear shocks in an attempt to comply are allowed.

2) Any fork, to a maximum of 44mm stanchion is allowed.
2a) Forks must be of ORIGINAL manufacture drum brake design.
2b) NO re-engineering of disc brake design forks in an attempt to comply are allowed.
2c) All forks must be of conventional type. NO USD forks are allowed

3) Brakes must be drum type, front and rear. No disc brakes.

4) Any Engine MUST be Aircooled and be from an original twin shock motocross/enduro frame motor cycle. Engines from Yamaha non linkage "monoshock" motocross/enduro frame motorcycles are allowed.
4b) Engines can be of Four or Two stroke design.
4c) Carburetors must be round slide or period flat slide type.
4d) The use of aftermarket reed blocks is allowed.

4e) No hydraulic clutch mechanism can be used.

5) Replica after market swing arms are allowed.
 
6) Handle bars must be 7/8th cross bar design fitted with a protection pad.
6a) Any type of handle bar controls are allowed.
6b) NO fat bar design handle bar is allowed.

7) Footpegs must be of the folding type with a self returning mechanism.

8) A chain guide/guard must be utilised and cover the point of chain return onto the rear drive sprocket.

9) All motorcycles must have an effective muffler/silencer fitted.


This is NOT about the CR Honda's. This is about trying to make a clear and concise set of rules to STOP all the BS that goes on just before National events and letting all concerned know, in black and white, what is and what isn't allowed. Regardless of what has been accepted as kosher in the past, there are still those that get their collective noses out of joint and make the current rules into whatever they see them to be.
Mate I like your rules and it looks like we need some in depth rules such as these to stop punters finding loop holes..
   TBM, I like your take on a proposal for the rules as well. The only thing I can see after a quick look, is there is nothing that mentions what sort of carburettors or aftermarket reed blocks that are allowed.
   To be honest, although I am dead against Dutch twinshock style bikes, I have never really had a problem with the use of any air-cooled motor in a frame originally manufactured with twin shocks (such as a CR480 in a CR250RA frame). I think that the Phil Denton Engineering big bore Hondas built for the visiting USA riders at the Farleigh Castle VMXDN are awesome looking machines and are still in my opinion within the spirit of the sport. But I do accept that my viewpoint on this is probably not shared by the majority of Evo class riders in Australia. So yes, I think the the wording of the rules proposed by TBM, clears up most of the grey areas that I can see.   
I pretty much agree with you Mark and also like the Denton Hondas and it wouldn't bother me whether they were in or out..

I have made a few more amendments. See 4c, 4d and 4e which address carburetors, reeds and clutches.

I also like the big bore twin shock Honda's and I would love seeing them on startlines in Australia BUT, I think that would open up a whole new debate regarding what year cut off would be implemented for other brands of engine as well as the Honda.

Again, this is just a draft and any feedback will be taken into account before a submission is made. I think it's about time the rules were written for the majority of racers.....

 
Arrogance.....A way of life for the those that having nothing further to learn.

Offline flower pot racing

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Re: 79 CR250 Front End Conversion
« Reply #226 on: July 08, 2014, 09:48:47 pm »
mmm..

I have fox replica yokes that are for 43mm forks so you can stuff a bigger set of forks in your front end and use a better brake.

I now have alloy steering stems that press straight into the lower yoke and have been made for the CR250 78-79.

Absolute things of beauty, titanium fittings as standard.

I will ask a mate to post pics of them on a separate thread to keep out of this one.

Pretty sure they are £400 for the whole lot (plus postage)