kawamaha Posted April 5, 2010 (edited) if you're not too deep into the suspension theme, or even worse, your bike has not stock forks, you may have some trouble to identify your front shocks. so how to determine which kind of forks do I have (Japanese brands)? history of japanese MX-bikes equipped with Showa or Kayaba (KYB) forks: 1985 and older: non cartridge forks --> usually run 10wt oil, vary damping with oil wt. 1986-1988: '86 CR250 - first production cartridge fork. (today we call them "open bath cartridge" or "single cartridge") 1987 and 1988 most other 125cc -500cc bike followed. my knowledge isn`t that good about 80cc bikes, but I think some run non-cartridge forks till today. correct me, if I'm wrong --> since that, every fork (except non-cartridge) until today runs 5wt oil as std. the oil level is basically between 100mm and 140mm (except "bladder forks" - used on late KYB's. oil level there is 70-100mm) on open bath cartridge forks rebound is on top! how to change fork seals and oil: 1997: again Honda started a new generation - closed cartridge (also called Twin chamber) forks Suzuki also started with Twin chamber forks in 1997, but these forks were RSU (right side up) KYB started their closed cartridge forks in 2005 it's almost impossible to measure the oil height, so the oil volume is specified on closed cartridge forks compression is on top! some bikes never changed to closed cartridge systems (KX125, Yamaha WR's) how to change fork seals and oil: now have a good ride, regardless of which fork you have 👍 Edited April 7, 2010 by kawamaha 2 Share this post Link to post Share on other sites
kawamaha Posted January 25, 2013 ok, until 2010 you see the Showa Twin Chamber fork (left in the picture above) and the KYB closed Cartridge fork (bottom) as stock forks in the bikes of the big four. so in 2011 and later, new forks were introduced. 2011 and 2012 KX450F forks remains the same, but got blue anodized caps. now have a look at SFF and PSF forks: Share this post Link to post Share on other sites
ds1434 Posted January 25, 2013 Actually 1994-1995 rm's had the first twin chambers USD forks. 45mm tubes 1996-1998 rm's had RSU twin chambers 49mm tubes 1999-2000 rm's had USD twin chambers 49mm tubes 2001-2003 rm 250's had kyb 46mm open chambers 2004 up rm 250's had 47mm twin chambers 2001 up rm 125's had 47mm twin chambers Great write up though especially with the pics as I haven't had a 13' kx250f through the shop and didn't know the fork cap had changed!! Share this post Link to post Share on other sites
kawamaha Posted January 26, 2013 Actually 1994-1995 rm's had the first twin chambers USD forks. 45mm tubes yes, meanwhile this info arrived at my home I also have the hundreds of different suzuki forks in my database, but would be great to have some pics of these forks, too... Share this post Link to post Share on other sites
jwaseman Posted January 26, 2013 Very good write up! Thanks! Share this post Link to post Share on other sites
kawamaha Posted October 30, 2014 (edited) PSF, SFF, TAC...what?here are the 2015 forks: all the 2014 KYB and Showa fork caps look like the 2013 caps P.S. if you are looking for YZ forks, you are way too far down the page Edited October 30, 2014 by kawamaha 2 Share this post Link to post Share on other sites
kan3 Posted October 30, 2014 What's with the different fork caps for the same air forks for different bike brands? Share this post Link to post Share on other sites
mog Posted October 30, 2014 Some don't recommend pressure in the outer chamber eg honda 250 but Kawasaki and suzuki do 2 Share this post Link to post Share on other sites
wblake Posted November 2, 2014 Good write up Kawahama Share this post Link to post Share on other sites
kawamaha Posted August 28, 2015 2016 forks: http://motocrossactionmag.com/home-page/super-tech-the-differences-in-fork-Technology I never thought that I would link to SSS-hype-mag when it comes to fork technology, but this overview isn't too bad I think... Share this post Link to post Share on other sites
Sheriff245 Posted December 19, 2018 On 8/28/2015 at 2:52 AM, kawamaha said: 2016 forks: http://motocrossactionmag.com/home-page/super-tech-the-differences-in-fork-Technology I never thought that I would link to SSS-hype-mag when it comes to fork technology, but this overview isn't too bad I think... Very interesting read, except that they got something wrong: while the PSF-2 fork is an open chamber fork, the PSF (or PSF-1) was dual chamber (think SSS/AOS without a metal spring and larger cartridge). 1 Share this post Link to post Share on other sites
Michealmolach1 Posted May 22, 2020 Kawamaha, Thanks for this great and useful article. I did a quick search to see if there was something similar for rear shocks but don't see anything. Do you know of anything, would you like to make a similar rear shock article? My specifics are that i have a 2001 WR426 and the shock is leaking. I think that between myself and my friend we can handle the job but i did want to read up on this specific shock and especially get oil specifics. A general article would give folks a great resource. Thanks. Share this post Link to post Share on other sites
mog Posted May 22, 2020 You tube has videos All bladder shocks are basically the same Share this post Link to post Share on other sites