YZF forks........

[DB Cooper]

Hey folks,
It's raining and I can't go riding so moditis is kicking in.  I want to upgrade the forks on my '88 3CV, so I'm considering the YZF600 front fork conversion.  I'd love some USD's, but there's  too many parts to track down, and too much ($$$) machining.  I already have blue pots, braided lines, R1 M/C, etc.  It looks like I just need the forks, wheel, fender and triple trees. My question is, if both FJ and YZF forks are 41mm, why are the triple trees required?  I tried looking through the posts, but I can't seem to find out why.  Is moditis making me so blind I'm missing the obvious?
Thanks
Kevin

[FJmonkey]

My question is, if both FJ and YZF forks are 41mm, why are the triple trees required?  I tried looking through the posts, but I can't seem to find out why.  Is moditis making me so blind I'm missing the obvious?
Thanks
Kevin

YES!
USD forks are Up Side Down.... The 41mm tubes are no longer in the same place as before. 41mm in the triple tree is now 41mm at the axle. So the larger part of the forks need to be clamped in the triple tree....

[DB Cooper]

The YZF600 forks RSU's (right side up) . I would just like to go USD's.
Kevin

[DB Cooper]

Sorry, just re-read the first post, and realized that I wasn't too clear (I'll blame it on the moditis). The YZF600 forks are a standard set up. It looks like the
uppers are 41 mm and should just fit in? Just wondering why the triples are needed?
Kevin

[FJmonkey]

Sorry, just re-read the first post, and realized that I wasn't too clear (I'll blame it on the moditis). The YZF600 forks are a standard set up. It looks like the
uppers are 41 mm and should just fit in? Just wondering why the triples are needed?
Kevin

My bad on the USD issue, I also read a detail that did not exist. I am gonna guess that the spacing between the forks and the axle length need to be controlled. Don't want to spread or stretch the bottom of the forks cuz the triple is off....

[DB Cooper]

Thanks FJMonkey.
I knew it to be something obvious. Too bad, because it would mean a new bar, bar risers, possibly longer throttle cables, longer clutch line, longer front brake lines, etc etc etc.  More than I want to put into the bike right now. I'll have to find something else to mod for now. Time to go shopping at RPM!
Kevin

[FJmonkey]

Thanks FJMonkey.
I knew it to be something obvious. Too bad, because it would mean a new bar, bar risers, possibly longer throttle cables, longer clutch line, longer front brake lines, etc etc etc.  More than I want to put into the bike right now. I'll have to find something else to mod for now. Time to go shopping at RPM!
Kevin

Guess this means you have time to find bargain prices on a good set of USD forks, Buy low and upgrade as budget permits.  The axle thing was quite easy for me. I am upgrading my 86' to 89' forks and 88' FZR1000 front wheel. I missed the simple fact that I need the 89+ axle..... Oops....

[Brian S]

I bought mine with the yzf600 forks already done but I still have the stock fj triple assembly. If I remember correctly the previous owner used a gs750 rear axle up front? and a couple washers with the yzf front wheel. He is a member of this forum "Silvergoat", maybe you could fire him an email and ask what he did.

[Brian S]

Just found the former owners post. He used a 85 suzuki gs700es rear axle with 5mm inboard spacers(a couple machined washers) and one washer on each side outside the lowers as the axle is a bit long. The speedo drive still reaches the groove in the fork lower. Not sure if it matters but my forks are from a 95 yzf. I'm new on here and no expert by any means but I hope this is useful.

[Brian S]

I think there are also some spacers on the blue pot calipers. If you are serious and need any measurements I will gladly disassemble and break out the calipers.

[DB Cooper]

Hey Brian,
Thanks for the reply. That is what I needed to hear. Thanks for the offer of measuring, but as long as I know it can be done using the stock triples, I'll go from there. I just need to start rounding up parts for the up coming winter.
Thanks again
Kevin

[JCainFJ]

 Jon Cain here, I did this mod first back in 1998. You need the 87-88 FZR1000 triple so that the YZF fenders, axle, spacers, wheel, and discs line up. If you use the FJ triple, the FJ fender will not fit and the YZF600r fender wont fit either. Its much easier to find and mod an FZR1000 triple than it is to make all of the custom parts needed to make the FJ triples work.  The FJ triple is 190mm tube CL to tube CL, and the FZR1000 is 200mm, just like the YZF600. The FZR1000 triple is a cheep part on eBay and FJ bearings are correct. The FZR1000 upper triple will need two  changes. The main switch lugs will need to be shortened, so that the steering lock will line up. The switch opening in the upper triple will also need to be bored out a bit too. The stock FJ bars will work on the FZR1000 triples, and all of your stock cables, hoses, and bar switches will work too. If you have any other questions about the mod, or the YZF600r rear wheel mod, sen me a P.M.. I will help all that I can.

Ride Well,
Jon

[BSI]

Jon

do you suggest putting a fork brace on the YZF600 forks?...thanks for all your input 

Louie

[DB Cooper]

Thanks Jon.
It will probably take all summer to find the parts, especially the FZR triples, but I may take you up on the offer for some questions at a later date.
Ebay, here I come!
Kevin

[JCainFJ]

Louie,

I do not recommend a fork brace for the YZF600r forks. All the braces I've seen have problems or cause problems.

Kevin,

Keep an eye on eBay and you will find everything you need. P.M. me with any questions!