OzVMX Forum

Marque Remarks => Honda => Topic started by: Josha on April 29, 2017, 09:29:41 pm

Title: Info on Gary Jones' 73 RC250
Post by: Josha on April 29, 2017, 09:29:41 pm
Hi Guys,

I picked up a 1973 CR250M frame with some crazy mods done to it with the rear shock mounts. After doing some research it looks a lot like the 73 RC250. I think this is what someone was trying to do. I am thinking about continuing with it and make a RC250 replica. Any info would be appreciated. I know the barrel was modified to accommodate reeds. The swingarm looks like box section as well. And the tank has totally mounting too.

(http://i1144.photobucket.com/albums/o494/joshacool2/1975%20Honda%20MT%20250/76541973HondaRC250WorksBike_zps4qhozzzo.jpg) (http://s1144.photobucket.com/user/joshacool2/media/1975%20Honda%20MT%20250/76541973HondaRC250WorksBike_zps4qhozzzo.jpg.html)

Title: Re: Info on Gary Jones' 73 RC250
Post by: Rossvickicampbell on April 30, 2017, 06:47:34 am
I can't access FB from here at work to give you the link but a photo of the RC you are talking about floating on the Honda or OZVMX pages currently.
Title: Re: Info on Gary Jones' 73 RC250
Post by: Rossvickicampbell on April 30, 2017, 09:32:24 am
Honda Elsinore and CR - but it might be your photo Josh?
Title: Re: Info on Gary Jones' 73 RC250
Post by: BSA-B5 on April 30, 2017, 09:09:49 pm
It would be only eligible to run in pre 78 classes, i hope you will realize that, if you where to enter the bike when finished at the Australia Vintage titles as a pre 75 bike, you will be knocked back in those classes.
Title: Re: Info on Gary Jones' 73 RC250
Post by: jimg1au on May 01, 2017, 07:59:43 am
i have a replica barrel for that bike Yamaha reed welded into inlet port
Title: Re: Info on Gary Jones' 73 RC250
Post by: skypig on May 01, 2017, 09:17:01 am
Not sure if this link will work as intended.
http://advrider.com/index.php?threads/building-a-1981-yamaha-yz465-factory-replica.772033/page-27

Go to page 27 and check out the info that used to be in bike magazines. :)
(These days it would be: "we sent the bike away, it came back with some anodized bling, and better suspension and power") :o
Title: Re: Info on Gary Jones' 73 RC250
Post by: skypig on May 01, 2017, 09:22:32 am
It would be only eligible to run in pre 78 classes, i hope you will realize that, if you where to enter the bike when finished at the Australia Vintage titles as a pre 75 bike, you will be knocked back in those classes.

Why is that?
The bike was raced in '73, but not eligible for pre 75?
(Not arguing, just interested. I'm guessing it's related to suspension travel.)
Title: Re: Info on Gary Jones' 73 RC250
Post by: Rossvickicampbell on May 01, 2017, 09:53:17 am
slightly off topic as I know we are talking a replica rather than the real thing - but works bikes apparently are a big grey area for MA - have seen people knocked back with works parts - because they weren't available to the public even though period correct.
Title: Re: Info on Gary Jones' 73 RC250
Post by: Oldfart on May 01, 2017, 11:39:42 am
skypig ....think they are relating to rear suspension travel. pre 75 is 7 inches  front and front 4 at the rear.
Title: Re: Info on Gary Jones' 73 RC250
Post by: Momus on May 01, 2017, 01:50:44 pm
It would be only eligible to run in pre 78 classes, i hope you will realize that, if you where to enter the bike when finished at the Australia Vintage titles as a pre 75 bike, you will be knocked back in those classes.

Why is that?
The bike was raced in '73, but not eligible for pre 75?
(Not arguing, just interested. I'm guessing it's related to suspension travel.)

My take is that it would not be Pre 78 legal either. Pre 78 is specifically for '75, '76 and '77  machimes. It is not a 'ride up'  or opt in category.
Title: Re: Info on Gary Jones' 73 RC250
Post by: skypig on May 01, 2017, 02:16:43 pm
It would be only eligible to run in pre 78 classes, i hope you will realize that, if you where to enter the bike when finished at the Australia Vintage titles as a pre 75 bike, you will be knocked back in those classes.

Why is that?
The bike was raced in '73, but not eligible for pre 75?
(Not arguing, just interested. I'm guessing it's related to suspension travel.)my take is that it wouldtnot be  Pre 78 legal. Pre 78 is specifically for '75, '76 and '77  machimes. It is not a ride I p  or opt in category.

I don't understand the comment. Looks like a little "spell check" intervention there?
This is a '73 model, with '73 period mods, as raced in 1973, by Gary Jones.
But the answer seems to be the rear travel exceeds the modern rules for pre '75.
Title: Re: Info on Gary Jones' 73 RC250
Post by: Iain Cameron on May 01, 2017, 06:48:07 pm
Skypig there are a number of bikes in pre75 and pre 78 that exceed the suspension travel limits so to be able to race in the class they need to be backward engineered to limit to the class . In pre 75 the YZb's and in pre 78 the YZd's .
Title: Re: Info on Gary Jones' 73 RC250
Post by: bigk on May 01, 2017, 07:34:36 pm
The frame came from me, the mods are fairly extreme. There's no way on earth it will qualify for Australian pre'75 class rules in it's current form. I don't know but I'd imagine the mods were made way back in the day in an attempt to compete with RM A's/B's etc, long before a pre'75 class existed.
K
Title: Re: Info on Gary Jones' 73 RC250
Post by: LWC82PE on May 01, 2017, 08:46:29 pm
This might be good for some info although its a 125
https://www.mxworksbike.com/index.php/1972-honda-rc125m

Rick Gill @ Rick Gill Honda in WA was doing these sort of mods to Hondas back in the 70’s This one is a modded 1975 CR250
As soon as BigK said that above I immediately thought of this. They were doing it to use up surplus/over supply of the 75 models and make them competitive against new/more advanced bikes so maybe even could have been doing it to 73/74’s at a later date too. Maybe a customer wanted his older model updated?
This scan is from a 1978 published magazine article on converting the 75 CR250 to MR enduro specs. They mentioned that Rick Gill Honda was doing these frame mods to get 250mm+ travel from the 75 and maybe earlier? for the WA team Honda bikes in motocross. He was putting Marzocchi leading axle forks on them too so this was around 76-78 for sure.

(http://i1105.photobucket.com/albums/h357/30782/75mod_zpsryvgxnub.jpg~original)

(http://i1105.photobucket.com/albums/h357/30782/honda2_zpsqnynhjon.jpg~original)