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Kayaba 43mm Forks in which bikes?

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I´m currently working on my 1981 Yamaha YZ465 and want to upgrade the suspension.

Shock is already Ohlins, at the Forks i need some improvement too.

I know the RaceTech Cartridge emulators but wonder if it is possible to do something else.

 

For this reason i am looking for information about the 43mm Kayaba conventional Forks.

 

Later models were equipped with a cartridge while the first models are normal damping rod style Forks.

 

My idea is to take the cartridge out of a later model (to benefit from the Shim equipped damping system), rework it to my needs (eventually add a adjustable compressium damping system) and implant it in my 81 YZ´s tobes.

 

I know it is plenty of work, but i have the machinary and the suspension know how from a tuner who is a good friend.

 

I want to figure out which Dirtbikes (NO MATTER WHICH BRAND) carry the 43mm Kayaba conventional Fork with a cartridge system inside (external clickers for rebound and maybe compression).

 

I would be pleased to have input from you all here in the forum to make a table with the information which

Make/Model/Year Bike has the 43 Kayaba Fork.

 

This may be interesting for the Vintage Racing Community too, maybe someone already swapped the internals of this fork

and can help me out with his knowledge.

 

Thank you for reading this and for your time!!

 

Michael

 

 

 

 

 

 

 

 

 

 

 

 

 

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Sounds unique so if that has appeal that's different. Otherwise I doubt seriously that any of the stock setups from 20-30 years ago, even the cartridge type were as good Gold Valve equipped stockers, though it might be close. Given the extra hassle I wouldn't bother, but we all have different ideas. 😉

PS - I put USD CR forks on my XR350 and LOVE it, but also a PITA with all the small parts needed adding up ($$) and the "Frankenstein" nature of it now. (bearings and spacers and everything being non standard)

FWIW 🙂

Edited by MindBlower

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Thank you for the help so long, the goal is to have a more modern damping system in the old forks.

Our vintage Race class restrict us to 43mm conventional forks, drum brakes, air cooled engines and

twinshock or non linked monos.

 

thats why i want to convert the forks internals for better performance...   🙂

 

Cheers, Michael

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Currently putting an '83 TT600 front end on an XT500. I can't comment on the internals, as I haven't opened up the forks yet, but the '83 and '84 TT600 are definitely 43mm and drum.

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Thank you for the help so long, the goal is to have a more modern damping system in the old forks.

Our vintage Race class restrict us to 43mm conventional forks, drum brakes, air cooled engines and

twinshock or non linked monos.

 

thats why i want to convert the forks internals for better performance...   🙂

 

Cheers, Michael

I believe in Yamaha's case the disc brake came out before the cartridge fork, the cartridge bolt is a lot larger than the damper rod bolt.so too easily get a cartridge fork would mean a disc brake upgrade,,,,, whether machininng the lower fork tubes is feasible I wouldn't know

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KYB 43 ḿainely on '83/'84 to '88/'89 Yamaha, Suzuki and Kawasaki. Showa on Honda.

 

The internals differs from the earlier cartridges to the latest. 

 

Look at http://www.mrcycles.com/ for the differences (parts-list).

 

Hier some pics http://www.motodacross.com/index.html just click on the brand and select the model you want to see. Scoll to see the oldest.

 

The easiest way is to swith the complete fork for a '88-fork and make an adapter for the drum plate. 

I you are interrested, I can show you some examples, but they are on french forums. I wonder if you can read this language.

 

Do you have the specification chart of your Öhlins demper?

 

Cheers

 

Jean

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My 88 YZ250 is and I believe the 89 YZwas USD but the 89 WR250 may have been conventional ?  I've also got a set of 88 yz125's same thing.

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deleted my post...

 

figure out it was for conventional forks and not inverted 43mm's

Edited by mlatour

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The forks can have been different from country to country.

 

In France, the 43-forks came generally 1983, and the switch to USD was 1988/89.

 

Other countries had 38 forks till 1885.

 

jeanjean

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Thank you for all the input!

 

As i mentionen i want to have a proper working suspension in my racebike.

I also want to stay as original as possible with the look but with modern internals.

Any suggestions are welcome!

 

 

 

@djidji

 

Thank you for your offer to show me the examples, i will happily take advantage of this.

 

I neither am able to speak nor have the capability of reading the french speech...

 

So please guide me!

 

What do you want to know exactly about the Ohlins shock?

 

 

 

Greetings, Michael

Edited by Cannon0873

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Hi Michael,

 

I'm interrested in the specifications card (something like the following)

 

34993d1281763027-i-m-looking-workshop-ma

 

or at least in the shims stacks.

 

Regarding the brake shoe plate, the informations I have are splitted over several threads. I've just started a new one on a french forum to get the informations together.

 

http://www.leguidevert.com/_V6/viewtopic.php?pid=612020#p612020

 

Check if you can see the pictures.

 

The may be some examples too in the classic area of the german forum offroadforen.de, but I didn't check yet (I assume, you are german speaker...).

 

Regards,

 

jeanjean

Edited by djidji

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The forks you REALLY want to gut are the 1986-88 CR250/500 forks. Be prepared to fork out some serious $$$ for those, however. 

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...well, I'm not sure...

 

The 1986-88 CR250/500 forks have no compression rebound clickers and a 20 mm cartridge.

 

The KYB 46 of the '89 kawa' and suz' may be way better. Compression and rebound adjusters, 25 mm cartridge.

 

The Honda XR400 fork (Showa 43) has compression and rebound adjusters, but still the 20 mm cartridge.

Some of them have been modified to fit the 25 mm cartridge of the 43 USB fork of the 93' CR, which implies some machining...

 

Cheers,

 

jeanjean

Edited by djidji

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The 87 CR250 I rode had stone stock forks save ATK triple rate fork springs (I was told what the rate was, promptly forgot) and I didn't feel like I needed adjustable compression dampening on the forks. I rode it around a very chopped out sandy track, and a more hard packed modern track a few times before giving it back to its owner.  

Another 43mm fork with cartridges is the later model (97-99) Suzuki DR350. It's a shorter travel bike at 11.0 inches in the front, but the guts might be able to be reworked for longer travel. Compression and rebound adjustable, BUT the Suzuki service manual refers to the cartridge as non-serviceable. Not sure if any decent tech could do it or not

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...rebound clickers...

 

They all have compression adjusters at the bottom.

 

jeanjean

 

The 1986-88 CR250/500 forks have no compression clickers and a 20 mm cartridge.

Edited by djidji

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