David Pingree on air forks

GouldRacing25 wrote:

Yes correct. These forks are off my 15 yz250f. Id look for 14+ yzf forks or 15+ yz forks.

MXD wrote:

Are there any major differences between the 14-15 SSS KYBs and the older ones? In other words, if I found a set off of an 08...

Are there any major differences between the 14-15 SSS KYBs and the older ones? In other words, if I found a set off of an 08 or 09 but was going to get them revalved for me anyway, would it matter?

Mit12 wrote:

RV seemed to do just fine with air forks.

h&m_cycle wrote:

Yeah, I heard he won last week... Did those Oxygen Forks cause the ass wheelie? Yeah, that's what did him in... rebound right on his ass...

Yeah, I heard he won last week... Did those Oxygen Forks cause the ass wheelie?

Yeah, that's what did him in... rebound right on his ass...

Rich Piano wrote:

Wonder when F1 will start running air shocks?

They havent ran valve springs for decades

Rich Piano wrote:

Wonder when F1 will start running air shocks?

They havent ran valve springs for decades

Fearo wrote:

Never? The sport that spends millions to save grams uses coil spring shocks. Meanwhile, a sport where suspension comfort is 10 times more important than weight...

Never?

The sport that spends millions to save grams uses coil spring shocks.

Meanwhile, a sport where suspension comfort is 10 times more important than weight, sees them as the holy grail.......

Rich Piano wrote:

Wonder when F1 will start running air shocks?

They havent ran valve springs for decades

Fearo wrote:

Never? The sport that spends millions to save grams uses coil spring shocks. Meanwhile, a sport where suspension comfort is 10 times more important than weight...

Never?

The sport that spends millions to save grams uses coil spring shocks.

Meanwhile, a sport where suspension comfort is 10 times more important than weight, sees them as the holy grail.......

2strokerider wrote:

hit the nail on the head! you will never get the same performance / consistent damping/ feel from an air suspension unit that you can get...

hit the nail on the head!

you will never get the same performance / consistent damping/ feel from an air suspension unit that you can get from a spring/ oil set up...

Darryl916 wrote:

Air forks on a 2 stroke will actually be better. Spring forks are better on a 4 stroke, ...primarily a 450. It's because of torque. 2...

Air forks on a 2 stroke will actually be better. Spring forks are better on a 4 stroke, ...primarily a 450.

It's because of torque. 2 strokes don't have the suspension binding torque and mass of the thumpers so the vague "dead" feeling of the air forks will actually help the bike feel more stable in your hands. It will take away some of the racy "zing zing" explosive feeling inherent to 2 strokes.

450s have gobs of torque everywhere and that torque inhibits suspension travel. This and the heavy weight of 450s paired with air forks makes the bike feel like a big brick. Dead as fuuuu... Springs wake it up and provides more of an active feel.

I have felt some really good air forks but they were too soft for my weight and ability so naturally they felt very plush blowing thru the stroke in light chop.

Mit12 wrote:

We are talking about forks not the shock. Torque does bind forks.

Rich Piano wrote:

Wonder when F1 will start running air shocks?

They havent ran valve springs for decades

theycallmeebryan wrote:

I bought my '15 KX450f this past August, and have put 16 hours on the bike since then. For reference, I am 190lbs naked, 6'1", and...

I bought my '15 KX450f this past August, and have put 16 hours on the bike since then. For reference, I am 190lbs naked, 6'1", and am a C class rider that can jump everything.

My very first day on the bike I adjusted my forks to the factory setting of (145psi Inner / 7.5psi Outer / 131psi Balance) and the fork tubes 5mm from the flush in the clamps. What i failed to do is adjust the fork pressures with the front end off the ground. This left my forks compressed about 1 inch at rest. In this configuration, the fork felt very soft, the front end was very low, and the bike was very twitchy and knifed in the corners. You can see the fork partially compressed in the following picture. The upper fork leg should be about even with the top of the fork guard with no weight on it.



Even after setting the factory recommended pressures properly with the front wheel off the ground, it felt way too soft.

Over time, i decided to play around with the settings, and tried Team Green's recommended settings. (page 21 here: http://issuu.com/541marketing/docs/2015_teamgreennews ) For my weight, TG recommends (174psi Inner / 7.2 Outer / 174 Balance) and Rebound 12 clicks out, Compression 6-12 clicks out. I started with 6 clicks out on the compression. This setting definitely felt better, but it felt like the front end wasn't getting enough traction and was beating me up over the small chop, making me lose confidence and forcing me to tip toe through corners. I then decided to jump to the other end of the compression spectrum and try 12 clicks out. The front end definitely felt better in corners and over small chop, but now i was bottoming on some of the larger jumps at Pala. My wrists didnt like that.

After further testing, and with help of the SFF Air app, I decided to utilize less inner pressure and more outer pressure. You see, outer pressure effects the linearity of the spring force. More outer pressure allows for a more ramped spring pressure. Right now I've found a happy setting of (155psi Inner / 13psi Outer / 165psi Balance), Rebound 12 clicks out, and compression 8 clicks out (compression varies a few clicks each way depending on the track). I've found that running a higher Balance pressure than the inner pressure allows the suspension to initiate the stroke more easily, allowing it to soak up the chop a bit better and not chatter in the corners. This has been my happy medium setting to handle most tracks in SoCal, with minor adjustments here and there.

I have to agree with Pingree that these forks perform well in a certain area with the trade-off of performing poorly on the opposite end. It seems like i can tune the fork for great traction and to handle small chop well, but it does not handle larger hits the best in that configuration. And vice versa the other way.

What I do like is that I'm able to soften up the spring a little on tracks where the jumps are not as big, which allows my front end to bite harder. On bigger tracks, i can stiffen it up a little to handle larger hits. Having said this, i think a lot of guys play way too much with the spring pressures and forget about the clicker settings. I don't sway too much on the pressures unless i find myself bottoming a lot, then i'll add a small amount of inner (maybe 5 psi) and outer (maybe .5psi) pressure.

What i don't like is the stiction these forks have at the topped out position and the first inch or so of travel. Seems to be a problem with the seals from what i read on Thumpertalk and from talking to various people.

I don't understand what the big deal is with checking pressures every ride. I don't find it a problem. It's an additional 3 minutes of pre-ride bike prep to do, and it's become part of my routine after I unload the bike at the track. No big deal.

That all having been said, I have a steelie YZ250 back east (need to get that over here) with full RaceTech suspension that handles beautifully, and i've heard great things about these forks when they are revalved. So soon i'll be contacting them for a revalve on my Kx450.

Markopolo400 wrote:

Nitrogen still changes pressure, Ideal gas law says so.

G-man wrote:

I will never buy a motocross bike with air forks.
True story.

As many have said backwards technology from the seventies.

G-man wrote:

I will never buy a motocross bike with air forks.
True story.

As many have said backwards technology from the seventies.

kiwifan wrote:

Well you wont be buying a 2017 bike then, KTM is likely to have them and Yamaha might be too....so your choices are rapidly becoming limited...

Well you wont be buying a 2017 bike then, KTM is likely to have them and Yamaha might be too....so your choices are rapidly becoming limited.

Simple thing is get a conversion kit to spring if you dislike them so much or are incapable of setting them up.

G-man wrote:

I will never buy a motocross bike with air forks.
True story.

As many have said backwards technology from the seventies.

kiwifan wrote:

Well you wont be buying a 2017 bike then, KTM is likely to have them and Yamaha might be too....so your choices are rapidly becoming limited...

Well you wont be buying a 2017 bike then, KTM is likely to have them and Yamaha might be too....so your choices are rapidly becoming limited.

Simple thing is get a conversion kit to spring if you dislike them so much or are incapable of setting them up.

Jrewing wrote:

How do you set up psf-2 forks? Tell me please

G-man wrote:

I will never buy a motocross bike with air forks.
True story.

As many have said backwards technology from the seventies.

kiwifan wrote:

Well you wont be buying a 2017 bike then, KTM is likely to have them and Yamaha might be too....so your choices are rapidly becoming limited...

Well you wont be buying a 2017 bike then, KTM is likely to have them and Yamaha might be too....so your choices are rapidly becoming limited.

Simple thing is get a conversion kit to spring if you dislike them so much or are incapable of setting them up.

Jrewing wrote:

How do you set up psf-2 forks? Tell me please

Fearo wrote:

Never? The sport that spends millions to save grams uses coil spring shocks. Meanwhile, a sport where suspension comfort is 10 times more important than weight...

Never?

The sport that spends millions to save grams uses coil spring shocks.

Meanwhile, a sport where suspension comfort is 10 times more important than weight, sees them as the holy grail.......

2strokerider wrote:

hit the nail on the head! you will never get the same performance / consistent damping/ feel from an air suspension unit that you can get...

hit the nail on the head!

you will never get the same performance / consistent damping/ feel from an air suspension unit that you can get from a spring/ oil set up...

Mit12 wrote:

And how doea an air spring effect the dampening? Once you get the air pressure correct you do not change it. Just like springs.You do not...

And how doea an air spring effect the dampening? Once you get the air pressure correct you do not change it. Just like springs.You do not see riders changing springs at the track they adjust the clickers. What everyone is forgetting is when Honda came out the with the Aluminum frame EVERYONE hated it. Did honda scrap the idea? No they refined it and made it better. Now Kawasiki, Suzuki and Yamaha have them. KTM has tested and are devolipimg an Aluminum frame.The same thing will happen with air forks.

Jrewing wrote:

How do you set up psf-2 forks? Tell me please

zehn wrote:

By selling them and buying PSF1 forks. PSF2 are open-bath designs from the early 90s. All the pros running KYB air forks use the PSF1.

TeamGreen wrote:

I shared some of the looniness in this thread with some engineers I know in England and Italy.

They laughed their asses off.

StartedTooLate wrote:

Conventional Spring (f = -kx) comparison... [img]https://p.vitalmx.com/photos/forums/2015/11/18/111797/s1200_AirSpring.jpg[/img]

Conventional Spring (f = -kx) comparison...

Reefer Sutherland wrote:

There was a guy on this forum who made a thread about the 2015 CRF450 he purchased. He expressed his displeasure with the suspension, and was...

There was a guy on this forum who made a thread about the 2015 CRF450 he purchased. He expressed his displeasure with the suspension, and was very knowledgeable regarding suspension itself.

Naturally, every response to the thread was a shitty one-lined jab at the OP, just like 90% of the threads on here.

Now a year later, many of the same people who shit on that guy, are echoing the things he mentioned in that thread. He really nailed it. Cost savings measures. They stuck oversized cheap downhill MTB suspension on these things, told you it was the next best thing.

Go find that thread. It basically predicts this thread.