Vintage Dirt Bike Q & A

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PostPosted: Sun Nov 13, 2011 8:37 am 
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Joined: Wed Jun 22, 2011 10:50 pm
Posts: 16
Howdy guy's,After looking at Whymee's post about 1979 CR250R suspension questions.I don't want to hi-jack his thread so I will start my own.Am in the process of re-doing (istead of restoring :lol: )a '79 250.I am basicly going with a semi MOTO X FOX theme.Have the swingarm , a set of fox factory shox.Made the engine stays and air box ring.Now comes the front end.I will be racing the bike or should I say attempting to race .At 60 years old might not be the smartest thing ..LOL anyway,Was thinking about the '83 480 front setup to try to keep some of the cost down. Simons anywhere from $1500 to $2000 if you can get a set.Have heard that you need a set of trees made for the 480 front end to get the correct frame geometry.I talked to the guy's at AMS racing ( Tim and Dave) and was told that the 480 front end has the wrong offset and can actually hurt the handling of the bike.What do you guy's think is the best way to go.Bite the bullet and go with a set of Simons? FOXX FORX ?(have been told that they are really not the greatest).Try the 480 setup anyway? Try to improve the factory forks (drilling the holes in the dampner,air caps,springs,fork kit) I know I wont be able to get the full potential out of any of them because of age ,ability, talent,etc..............LOL. But I do want to try to have really good equipment. Back in the day I raced on a shoestring budget was lucky to have enough money for gas and oil.Hell I was lucky if I could get to the track.I actually have two '79 250R's .One is an all original very low hr.like new bike and the other is the one I am talking about. I have done engine mods and lots of other stuff and plan on really "tricking" it out.Sorry to be so long winded and thanks in advance .....Alton


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PostPosted: Tue Nov 15, 2011 7:39 am 
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Joined: Fri Feb 27, 2004 10:20 pm
Posts: 906
Location: San Clemente, CA
Would the people telling you need a set of triple clamps be the same folks who make a set of triple clamps? IMHO the '83 front-end is the best balance of availability, price and function. I could not even tell you what the 43mm triple clamps are on my bike, but I did slide the '83 CR480R forks up the make the bike turn quicker. You could spring for a custom set of triple clamps and still be ahead of what you might pay for Fox Forxx or Simons. If you get convinced you need the clamps, it opens up the possibility of putting an '81 YZ front-end on complete with what was considered to be the best front brake setup of the time. Food for thought.

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Michael Stiles
1979 Honda CR250R Elsinore | 2006 Husqvarna SM510R | 2007 Service Honda CR500R-AF


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PostPosted: Tue Nov 15, 2011 4:36 pm 
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Joined: Wed Jun 22, 2011 10:50 pm
Posts: 16
RR,Actually the guy's from AMS don't have the trees .One of the owners (Tim) Was elaborating his thoughts on the 43's.Funny you should mention the YZ .I have an old 490 ( 4 speed ) I think around '81 or '82 I keep looking at wondering how to get that front on the CR..LOL.If I am not mistaken don't you have to make a bushing to fit the '83 front to the '79 ?
I have a line on a '83 front pretty reasonable will probally go ahead with that .If that doesn't work out I can always get the rest of the 480 to go with the forks. :D Thanks for the input.....Alton


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PostPosted: Wed Nov 16, 2011 10:22 am 
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Joined: Fri Jul 14, 2006 8:12 am
Posts: 323
Location: Wuppertal/Germany
Swampdog wrote:
Have heard that you need a set of trees made for the 480 front end to get the correct frame geometry.I talked to the guy's at AMS racing ( Tim and Dave) and was told that the 480 front end has the wrong offset and can actually hurt the handling of the bike.What do you guy's think is the best way to go.

the problem is the 83 fork is longer, so you lift up the front and get a bad handling.
to get the right hight you can mount the tubes higher in the trees, the topcap is some inches above the upper clamp.
as i did when i installed a marzocchi magnum at my elsi.
Image

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PostPosted: Wed Nov 16, 2011 3:50 pm 
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Joined: Fri Feb 27, 2004 10:20 pm
Posts: 906
Location: San Clemente, CA
I just checked mine and there is 15mm of fork tube above the triple clamp, but they could go higher. The limit is determined by when the tire hits the fender at full compression. I did not have to make a spacer because I swapped my '79 steerer over to the new 43mm triple clamps. All you need is a large diameter washer to allow for the longer CR480R steerer if you go that route.

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Michael Stiles
1979 Honda CR250R Elsinore | 2006 Husqvarna SM510R | 2007 Service Honda CR500R-AF


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PostPosted: Thu Nov 17, 2011 1:21 pm 
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Joined: Wed Jun 22, 2011 10:50 pm
Posts: 16
Rocket and B-Joe Thank you both very much for all of the info.I certaily appreciate it.Looks like I will go with the 480 front.Was looking at the YZ front last night probaly would be no-go with the Yammie trees.the bars are directly over the forks with about 1mm of clearance between the air caps and handle bars.Have either of you had any experience with the Race-Tec Emulators and/or could tell me how they work.Also I think the yammie tubes might be the same dia. as the 480 might could slide them into the 480 trees (always trying to think of something else....LOL)I guess next I will start worrying the heck out of ya'll about Red paint.


BTW Nathan, Thanks for the great site and thanks to all of the great Elsie lovers that come here


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PostPosted: Fri Nov 18, 2011 9:07 pm 
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Joined: Fri Feb 27, 2004 10:20 pm
Posts: 906
Location: San Clemente, CA
I have had Race Tech emulators in my 43mm CR forks from the outset. Been very happy, but do not have a "before and after" comparison...

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Michael Stiles
1979 Honda CR250R Elsinore | 2006 Husqvarna SM510R | 2007 Service Honda CR500R-AF


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PostPosted: Sat Nov 19, 2011 1:42 pm 
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Joined: Tue Jul 20, 2010 5:29 am
Posts: 5
Location: North East UK
I have 83 480 forks on my Rocket and run them 10-12mm throtugh the forks, remember the top yoke will be higher as the stem is longer as well.
ImageI have the same setup on my 1980 125, again the forks through the yokes, I used the 125 stem with some shim paper as it was ever so slightly smaller.
Image


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