single chamber vs. dual chamber forks (04/05) ??

15 replies to this topic
  • Sparky_So_Cal

Posted July 28, 2004 - 10:40 AM


Just wanted to know the pro's & con's between the 04/05 Yamaha 450 forks. I don't know much about the technology that Kayaba is going to for 2005 w/ the dual chamber. Anybody have any knowledge in this area?

Thanks in advance,


  • Thumper38

Posted July 28, 2004 - 11:06 AM


That makes two of us?

  • RJB

Posted July 28, 2004 - 11:56 AM


In summary, I understand the reason is to keep the oil and air apart. Quite simple, although they do mix, the opinion seems to be that keeping oil and air separated, the performance is improved. I believe the Honda Showa forks have had this for a while. I can dig out a more detailed answer later on if you want

  • Thumper38

Posted July 29, 2004 - 02:00 AM


That would be great, thanks! :thumbsup: :devil:

  • Sparky_So_Cal

Posted July 29, 2004 - 03:53 AM



That would be awsome, It seems like that is the major difference between the 04 and 05


  • gonzo

Posted July 29, 2004 - 05:23 AM


Unfortunatly I am not hearing the good comments about the 05 suspension that I thought I was going to hear. Sort of upseting. I was hoping to hear it was the bomb and test riders are saying it's basically Ok.

  • Radbuster

Posted July 29, 2004 - 05:45 AM


Another question on the topic. Is it only the YZ's getting the new forks or will the WR's also get them? Doesn't look like it from the "news" part om Yammi's website.

  • Sparky_So_Cal

Posted July 29, 2004 - 06:45 AM


I am not as concerned about the stock suspension as I want to know about fine tweaking w/ a suspension shop. I am in the 250lb range and I haven't found ANY stock suspension which is good for me :thumbsup:

Just looking for the "so called" technology advances which it will "suposedly" provide.


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  • Ga426owner

Posted July 29, 2004 - 10:52 AM


Unfortunatly I am not hearing the good comments about the 05 suspension that I thought I was going to hear. Sort of upseting. I was hoping to hear it was the bomb and test riders are saying it's basically Ok.

well that is discouraging and I hope untrue.....I would hope that since Team Yamaha has been using dual Chamber forks for a couple of seasons that the kinks would be worked out. I guess the verdict is not out yet.......

  • RCannon

Posted July 29, 2004 - 01:32 PM


I have ridden several of the newer bikes from the various brands. My favorite forks are still the forks that were on the 98 Suzuki RM 250. Very nice to deal with. Firm, but not punishing.

My close second is the forks on a friends 2002 YZ 426. They were set up by MX Tech.

I dont think the technology means as much as the correct valving and set-up.

  • RJB

Posted August 05, 2004 - 09:13 AM


Sorry folks - still out of town and haven't had a chance to dig the details out. Also, I noticed the comment that you are 250lb. I believe that you would want to upgrade springs at a minimum for your weight. Also part of the reason that aftermarket companies specialising in shocks exist is that revalving and custom work seems to make big improvements in instances. Hopefully I can dig the article out next week and post you folks (that asked for it) the link

  • SoCal450

Posted August 05, 2004 - 10:03 AM


I think I can shed a little light on the subject. I really can't speak much for the technical aspect but the new forks are insane. I almost exclusively ride mx/sx at the hardpack so. calif. tracks and just picked up an '05 YZ125. Also I'm 165lbs as a reference point. I still have an '03 YZ450 that had the suspension dialed by precision concepts. For my '03 I thought they worked ok stock and were a little soft but worked much better after having them tuned. I have spent a little time on my brothers crf250 that has the twin chamber showas and felt the forks worked way better. They were much plusher and transmitted much less energy up through my upper body while retaining about the same bottoming comtrol. Granted it's a lighter bike and that of course makes their job easier. Well, on the limited time I've been on my '05 125 (1 good ride) I feel they are an equal improvement over the crf showas. Of coarse you also have to take this with a grain of salt because it's 20lbs lighter than the crf250 and that helps the suspension a lot. The plushness of the initial stroke over stutter bumps is leaps and bounds better than my revalved '03. It feels as if you float over them. You can sense this by simply sitting on the thing and putting pressure on the fork. It glides smoothly and consistantly at the first application of pressure where the '03 sticks initially then moves into the stroke. I have yet to really pound on it so the jury's out on bottoming control but my initial feedback on the '05 stuff is it's a considerable improvement, at least on the featherweight 125.

  • Sparky_So_Cal

Posted August 05, 2004 - 11:53 AM



Thanks, If you could provide any info that would be awsome. I am trying to determine weather the additional 1.3K is worth waiting for the 05 or picking up a new 04. I normally keep my bikes a min of two years and am planning on putting a fly wheel, magura clutch, flex bars and getting the suspension done (on which ever bike I get). Just trying to get an informed opinion on the fork technology. I am kinda of anal on the fork issue, because I had my forks re-valved FOUR times and still not totally happy w/ it and just gave up :thumbsup:

Thanks in advance,

  • RJB

Posted August 05, 2004 - 12:25 PM


Well, a few points on the spring rate (from RaceTech). For MX at 250lbs (04 YZ450), recommended rate is 0.490 kg/mm. Stock is 0.469 kg/mm. If you're riding SX :thumbsup: then its 0.510 kg/mm. Check out this link (at the bottom of the page) for some further info as well air volume chamber

  • grayracer513

Posted August 05, 2004 - 09:09 PM


The new YZ fork as I understand it is actually a sealed cartridge damping unit that is contained within the fork, kind of like having shocks in your forks. The fork tubes themselves are simply struts to contain the springs and to steer with, while the internal cartridges do the damping chores. The sealed units also mount upside down relative to standard practice, and the compression clickers are on the top, rebound on the bottom. I believe the cartridges are gas charged like the Bilstein type (deCarbon) shocks used in automotive applications to prevent foaming. I wonder if they are servicable (revalveable - rebuildable)?

Early reviews are almost universally raves.

  • MXKyle

Posted August 06, 2004 - 03:02 AM



just picked up an '05 YZ125. Also I'm 165lbs as a reference point. I still have an '03 YZ450 that had the suspension dialed by precision concepts.

I bought the first '03 around and haved learned to love it. My new '05 125 has just arrived too. Do you plan to keep your 450 and if so do you think you will have any trouble jumping back and forth between the two bikes?


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