BiMoTa Tesi also comes to mind also. cool stuff this thread led to some cool memory lane stuff, nice fotos Kelly.
I am fairly certain that Ryan Villopoto switched from the KYB that comes standard with the pneumatic spring technology for 2013 to Showa that does not... That is causing him some issues as he tries to get them dialed in. Who is this RC3 you keep referring to? Later,
yep, I rode one of these with the latest version of that front end and have never ridden a bike that flat ignored crap road conditions and had such amazing stability. Seemed like the limits were endless. It did impart a kinda dead feeling to the front end but was amazing charging hacked out back roads that had seen a lot of repair over the years.
Ther you go, put on a set Gabriel hijackers and you have the newest and lastest air suspended leading link front end. http://www.ebay.com/itm/Sachs-1968-...Parts_Accessories&hash=item2ec49ebbe1&vxp=mtr
yep, they have been doing hub steering designs for years, still are. Cool company. Yamaha actually sold a production bike with the RADD system for several years...
this interesting site is obsessed with these front end designs and has some cool geek stuff to look at. Sorry to derail this thread with my geeky love for the unusual. http://unlimited-eng.skyrock.com/
From some of the photo's on the net, RV's upper fork tubes are more a natural aluminum color http://www.motocrossactionmag.com/Main/Photos/Ryan-Villopoto-in-beast-mode-2019.aspx, unlike the gold Showa's in the above picture.....
Those are some funky designs ... Probably straight from a design point it might work .. On a muddy gnarled out trail ...the paper it was designed on would have been better used to start a fire with ... Is that DeCoster or Bon Jovi in the pic? Thanks and who would have guessed bmw knew all that? Fig. 9 was the greatest ... I'll put on my Einstein mock-up hat and read that article for the next 12 yrs and come back with a decision on what works best ... Hope CH is still around when the final decision is made ... ---
RC3? He's that short chubby dude in the booth calling the race ... Used to drive a truck in some of the nascar series or something .. He was a wash in the trucks ... Without such a fat shiny frame, the look of that kawi bike changes alot ..
Thanks and I'm exposed again as maybe senile .. I'll edit all this as needed if I don't forget .. . I've told my gf that when I get the clutch and front brakes positions confused, I might, might think about not riding ...
The KYB PSF fork (Pneumatic Spring Fork) comes standard on 2013 CRF450's and KXF450's only. It is lightyears ahead of the old airspring forks. Air is very progressive, which isn't the best thing in suspension. The MUCH larger volume of the newer forks, among other things, makes them less progressive than older designs. All forks utilize air as a spring, the trapped volume of air above the oil level (the whole reason changing oil level changes your fork performance/feel). However these forks utilize only air as the spring. Oil level can still be adjusted to tune a PSF fork. Standard air pressure is 33 PSI. 2 PSI equals a change of a traditional spring rate. Dry air vs nitrogen have very similar characteristics/performance (air IS mostly nitrogen). The main advantage of pure Nitrogen is it's larger molecule size, which doesn't permeat rubber like the oxygen molecules in air does. Though the teams *may* use nitrogen, for general use it isn't practical. We have been advised that the fork air pressure should be added to pre-ride checks, checked every ride similar to your fuel level and tire pressure. A special low-volume pump with a isolating shrader needs to be used for accurate settings, again 2 psi is a BIG deal. The main benefits of the PSF fork are 2 lbs lighter, and there is more room in the fork which has allowed for a larger cartridge diameter with larger piston/valvestacks. The jury is still out on weather it is better or not. It is lighter (good). It is more maintenance -intensive (bad). I'm still solidly behind traditional spring forks!
What about the blown seals on these type forks? Hope it is not like the case of a bike with no kick starter... I.E ... "Your Estart or battery will never fail" jargon ... We need space technology here but we all saw the space shuttle crash due to a giant o-ring going bad in the cold ... -- I'm still looking at the pic above with the 2 type forks compared side-by-side ... Looks weird as all the compressed air is on the top side and I don't really see what is holding the forks up and replacing the spring yet ... Unless it is that free piston? if so, seems like it should be named 'air stopper' or 'air plugger' instead .... EDIT: Wrong again as the blue color (compressed air) is on the top side and also goes to the bottom of the lower tube also and mixes with the oil there also ...
Thanks for the explanation, I have heard they aren't as sensitive to rising pressure due to heat, but didn't know why. If they are to be checked each ride, it seems that they could also have a pressure release to keep the spring effect close to the same and air added again when cold before the next ride. I like the idea of being able to change spring rates (pressure) for different conditions. The newer KTMs have external preload adjust, that must be nice for dualsport-with or without luggage.
Looks like 2 places here that can maybe blow chunks to my un-engineeing qualified eye ..... 1) At what ever that free piston is located at 2) At the oil lock ... This picture here is starting to come a little into focus ...
PS. I think the issue with RV is that his race pace is some much more faster than his practice pace that they haven't found that right pressure/balance for these SFF - teething problems but l doubt they will revert back. Local suspension tuner Terry Hay owner of Shock Treatment (good tuner) is looking at converting the KYB's off a posters 2010 TE450 into an air forks: "This is more interesting now. As I mentioned earlier KYB are proposing some form of bladder for future forks for the air pressure. Sounds like Showa are using the cartridge space for the air volume reducing pressure in the outer chamber. We converted our SFF forks on our KXF250 MX bike last year for Mitch Budd to test on and he loved it. Just couldn't bring myself to use it at National level though. All we did was to make a fitting that screwed into the bleed screw hole and had a schrader valve on it. 65 psi and away we went. This new system would be simple to make. A tube and plunger like a pushbike pump attached to the top and bottom of the fork. You could retro fit a cartridge for that matter. ...The easiest fork to retro fit this system to would be the WP twin chamber. You already have a gas fill point at the top of the fork an it wouldn't take to much work to make it suitable at all. Any fork can be SFF. Simply double up on the valving on one leg and run a spring force equal to two normal springs in the other. ...There are definite pros and cons for the air fork. Number 1 being initial plushness. One bad aspect for heavier or more aggressive riders is that as you increase pressure, preload increases as a consequence providing a harsher feel. By using an oversized damping chamber as an air spring component it could be supplemented with the outer chamber volume to promote additional bottoming without bolstering the initial pressure....sounding good so far."
