KTM aer strikes again 🤮

MX558
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MX558
So I picked up a low hr 22 350 . Today took it out to moto for the maiden voyage , the first session was great , absolutely loved the bike and thought the suspension was pretty damn good . Before the I take it off the stand and the fork totally collapsed. I tried pumping it up again and I could see it was losing pressure by the gauge. Then about an hour later I take it off the stand and all of a sudden it was holding pressure , so I pump it up to 156 PSI My Buddy goes and takes it out but I tell him don't jump anything cuz who knows what the hell is going to happen. Has anybody had this happen? Looks like time for a spring conversion lol
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GingerSnapRacing 4/10/2022 4:28pm
4/10/2022 4:28pm
To start simple you could make sure the schrader valve is in good condition.

Just to clarify you rode it, parked it, then took it off the stand and it collapsed?
Or you went to check pressure and it was really low?

Then you never got pressure built back up. Left it and it suddenly had pressure?

Just trying to help pinpoint the issue.
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willbilly
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willbilly 4/10/2022 4:49pm
4/10/2022 4:49pm
Next question will be was there a lot of pressure in the outer chamber when you opened the bleed screw.
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m21racing
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m21racing 4/10/2022 5:14pm
4/10/2022 5:14pm
Service the air side, and grease the piston. Not much to go wrong, if components serviced properly.
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MX558
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MX558 4/10/2022 7:05pm
4/10/2022 7:05pm
I checked pressure before the first session , rode it then when I took it off the stand for next session is when it collapsed . The weird thing is it then held pressure after an hour or so . That is when my buddy rode it but didn't jump anything for obvious reasons. It still holds air now but no way in hell I trust that again . These air systems are just shit . I am so glad this didn't happen over a jump . I've heard of other stuff like this happening . I love the bike so I will invest in a spring conversion. I've been riding over 45 years and never had something happen like this with spring forks
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Tuzzo123
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Tuzzo123 4/12/2022 8:53am
4/12/2022 8:53am
Your Schrader valve is probably stuck. Make sure you're not putting a side load on it.
MX558
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MX558 4/12/2022 1:28pm
4/12/2022 1:28pm
Tuzzo123 wrote:
Your Schrader valve is probably stuck. Make sure you're not putting a side load on it.
That is what my suspension guy said . The strange thing was I tried pumping them up an hour later and could see the air dropping . Then after another hour they seemed to hold air . Ive already ordered the TT KYB stuff and will have that put in . Too much headache with these air forks and I would have 0 confidence in them anymore . Thanks everyone for your help though . I really love the bike too
Rider 5280
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Rider 5280 4/12/2022 2:10pm
4/12/2022 2:10pm
Tuzzo123 wrote:
Your Schrader valve is probably stuck. Make sure you're not putting a side load on it.
MX558 wrote:
That is what my suspension guy said . The strange thing was I tried pumping them up an hour later and could see the air dropping...
That is what my suspension guy said . The strange thing was I tried pumping them up an hour later and could see the air dropping . Then after another hour they seemed to hold air . Ive already ordered the TT KYB stuff and will have that put in . Too much headache with these air forks and I would have 0 confidence in them anymore . Thanks everyone for your help though . I really love the bike too
What you described is freaking dangerous. I didn't think this could happen - I thought there was a failsafe incorporated.

Thanks for sharing this!
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MX558
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MX558 4/12/2022 3:53pm
4/12/2022 3:53pm
Tuzzo123 wrote:
Your Schrader valve is probably stuck. Make sure you're not putting a side load on it.
MX558 wrote:
That is what my suspension guy said . The strange thing was I tried pumping them up an hour later and could see the air dropping...
That is what my suspension guy said . The strange thing was I tried pumping them up an hour later and could see the air dropping . Then after another hour they seemed to hold air . Ive already ordered the TT KYB stuff and will have that put in . Too much headache with these air forks and I would have 0 confidence in them anymore . Thanks everyone for your help though . I really love the bike too
Rider 5280 wrote:
What you described is freaking dangerous. I didn't think this could happen - I thought there was a failsafe incorporated.

Thanks for sharing this!
I know right . That's why I'm going kyb and being done with it
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sandman768
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sandman768 4/12/2022 4:39pm
4/12/2022 4:39pm
My first Ktm had the Aer fork, I think 16.5 factory edition. I had reservations as I was coming off a 13 Honda with the worst air forks ever. right before a Moto, I checked the air pressure and the shader valve came out with the air pump ! I lost all the air in the fork & my Moto was getting close to starting, I pump it up and the valve came out again! I was finally able to air it up & get down to the line for my Moto! I was sweating bullets from pumping that dam little pump. I made my mind up right then & there, I was buying Cone valve spring forks. I have had the same cone valves for 5 years now, they go on all my new KTM”s as soon as I start riding them. I have them dialed in and it makes new bike setup much easier. The initial investment is steep, but 5 years of no revalves on forks that get sold, it ends up saving you $ in the long run, and the Cone valves have excellent resale value. With that said, I also have used the Aer”s while my cone valves are being serviced, and they have made incremental improvements to them. I had an 18 250sx that I was so comfortable on the Aer forks, I stopped switching the forks back & forth and just kept the Aer”s on, but I was riding the bike in mostly sand, where I feel the Aers actually work really good due to their adjustability and lack of any square edge hits. My cones are in for service right now, tomorrow I will ride with the Aer”s on my 21 350sx for the first time ever…I don’t mind playing with them to try and set them up… but I have never had a total failure on them.
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MX558
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MX558 4/13/2022 8:46am
4/13/2022 8:46am
I hear ya . If this was just an off road bike I'd keep the air but not for mx . I had a total failure over a jump back in 18 with air forks and tore my tricep so never again with these things
mxman
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mxman 4/13/2022 10:45am
4/13/2022 10:45am
I had a 13 Kawi, same thing happened. The next day I sent to Factory Connection. No way i'd hit a jump and not think about it. Now a KTM, same thing happened as you describe, next day ordered the Lucky Carbon's. I know ton's of people love the air forks, I just don't care for them.
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GingerSnapRacing 4/13/2022 11:05am
4/13/2022 11:05am
MX558 wrote:
That is what my suspension guy said . The strange thing was I tried pumping them up an hour later and could see the air dropping...
That is what my suspension guy said . The strange thing was I tried pumping them up an hour later and could see the air dropping . Then after another hour they seemed to hold air . Ive already ordered the TT KYB stuff and will have that put in . Too much headache with these air forks and I would have 0 confidence in them anymore . Thanks everyone for your help though . I really love the bike too
As someone who just went from AER to the TT KYB kit. You won’t be disappointed, I ordered mine from JBI, I’ve made a few small clicker adjustments from track to track but that’s about it. I personally have been lucky with 4 years in the air chamber with no failures. But I personally had been riding a few bikes with spring forks (kyb and Showa) and noticed the front end confidence. Made the switch and now I just plan to keep these forks and continue swapping them onto new bikes as long as I can.
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Rider 5280
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Rider 5280 4/13/2022 12:05pm
4/13/2022 12:05pm Edited Date/Time 4/16/2022 1:12am
A KTM newbie question:
I have KYB A-kit PSF1 air forks on one of my Hondas (and a Yamaha, too, actually - set up like Star Racing's bikes) --- I really like them. Both forks rely on air, but it'd be a crazy coincidence that BOTH forks would fail simultaneously, so I've not been too concerned (and I was told by Enzo that the KYB PSF1 fork cannot collapse). So, my question is regarding #1 in this KTM article:

https://www.ridektm.com.au/whats-new/air-forks-sorting-fact-from-fictio…

The OP's forks completely collapsed, right?

While I would still be scared as all get out after experiencing that, I am now wondering what the heck happened again (so I can know what to look for / have a prevention plan when using AER foks)?

-------------------------------

P.S. Ain't no amount of pontificating gonna change what happened, but if you ever figure it out, I'd love to know because I likely won't go full spring A-kit spring on a new KTM as soon as I get one.
wrc777
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wrc777 4/13/2022 2:11pm
4/13/2022 2:11pm
Rider 5280 wrote:
A KTM newbie question: I have KYB A-kit PSF1 air forks on one of my Hondas (and a Yamaha, too, actually - set up like Star...
A KTM newbie question:
I have KYB A-kit PSF1 air forks on one of my Hondas (and a Yamaha, too, actually - set up like Star Racing's bikes) --- I really like them. Both forks rely on air, but it'd be a crazy coincidence that BOTH forks would fail simultaneously, so I've not been too concerned (and I was told by Enzo that the KYB PSF1 fork cannot collapse). So, my question is regarding #1 in this KTM article:

https://www.ridektm.com.au/whats-new/air-forks-sorting-fact-from-fictio…

The OP's forks completely collapsed, right?

While I would still be scared as all get out after experiencing that, I am now wondering what the heck happened again (so I can know what to look for / have a prevention plan when using AER foks)?

-------------------------------

P.S. Ain't no amount of pontificating gonna change what happened, but if you ever figure it out, I'd love to know because I likely won't go full spring A-kit spring on a new KTM as soon as I get one.
All air forks will collapse if the schrader value fails/leaks.
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MX558
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MX558 4/13/2022 3:06pm
4/13/2022 3:06pm
Rider 5280 wrote:
A KTM newbie question: I have KYB A-kit PSF1 air forks on one of my Hondas (and a Yamaha, too, actually - set up like Star...
A KTM newbie question:
I have KYB A-kit PSF1 air forks on one of my Hondas (and a Yamaha, too, actually - set up like Star Racing's bikes) --- I really like them. Both forks rely on air, but it'd be a crazy coincidence that BOTH forks would fail simultaneously, so I've not been too concerned (and I was told by Enzo that the KYB PSF1 fork cannot collapse). So, my question is regarding #1 in this KTM article:

https://www.ridektm.com.au/whats-new/air-forks-sorting-fact-from-fictio…

The OP's forks completely collapsed, right?

While I would still be scared as all get out after experiencing that, I am now wondering what the heck happened again (so I can know what to look for / have a prevention plan when using AER foks)?

-------------------------------

P.S. Ain't no amount of pontificating gonna change what happened, but if you ever figure it out, I'd love to know because I likely won't go full spring A-kit spring on a new KTM as soon as I get one.
wrc777 wrote:
All air forks will collapse if the schrader value fails/leaks.
It may just be the Schrader valve that went bad but I'm not taking any chances , broken bones hurt lol
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wrc777
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wrc777 4/14/2022 5:04am
4/14/2022 5:04am
So you are running mousses instead of tubes too right? Same (or cheaper) valve in every tube.
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soggy
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soggy 4/14/2022 6:49am
4/14/2022 6:49am
wrc777 wrote:
So you are running mousses instead of tubes too right? Same (or cheaper) valve in every tube.
Doesn’t take a genius to figure out why a collapsing fork would be wildly more dangerous then a flat tire
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hylo
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hylo 4/14/2022 7:03am
4/14/2022 7:03am
I had a failure on the ‘17 250sx forks. I remember the EU versions got aer’s before the US versions did.

I got negative pressure on the air side and the fork compressed a few millimeters after each ride. I couldnt feel it before it had developed enough vacuum to compress them down as far as a couple of inches. A quick service and I was happy again.

Even though your forks suck right now you should take the time to try them out after the are repaired. I get the lack of confidence in how they will hold up, but generally people seem happy with them and you might save your hard earned bucks.

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wrc777
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wrc777 4/14/2022 7:32am
4/14/2022 7:32am
wrc777 wrote:
So you are running mousses instead of tubes too right? Same (or cheaper) valve in every tube.
soggy wrote:
Doesn’t take a genius to figure out why a collapsing fork would be wildly more dangerous then a flat tire
So you think the fork will lose air faster than the tire if the valve fails? What exactly do you think happens if you land with no air in a tube? At least if the air fails you still have the same air springs in the outer chamber in both legs that you have in a spring fork and the damper still works (that is what is taking most of the impact anyway).
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Rickyisms 4/14/2022 12:20pm
4/14/2022 12:20pm
hylo wrote:
I had a failure on the ‘17 250sx forks. I remember the EU versions got aer’s before the US versions did. I got negative pressure on...
I had a failure on the ‘17 250sx forks. I remember the EU versions got aer’s before the US versions did.

I got negative pressure on the air side and the fork compressed a few millimeters after each ride. I couldnt feel it before it had developed enough vacuum to compress them down as far as a couple of inches. A quick service and I was happy again.

Even though your forks suck right now you should take the time to try them out after the are repaired. I get the lack of confidence in how they will hold up, but generally people seem happy with them and you might save your hard earned bucks.
To me there’s nothing scarier than riding, racing, or jumping a bike you are not 100% confident of. I chased a rear brake problem for a while and it was a horrible feeling rolling up to the start of a 2 hour race knowing my rear brake would only last an hour at best.

If you’re not confident In your machine your head won’t be 100% and that’s how you end up somewhere you don’t want to be.
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hylo
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hylo 4/14/2022 1:02pm
4/14/2022 1:02pm
Rickyisms wrote:
To me there’s nothing scarier than riding, racing, or jumping a bike you are not 100% confident of. I chased a rear brake problem for a...
To me there’s nothing scarier than riding, racing, or jumping a bike you are not 100% confident of. I chased a rear brake problem for a while and it was a horrible feeling rolling up to the start of a 2 hour race knowing my rear brake would only last an hour at best.

If you’re not confident In your machine your head won’t be 100% and that’s how you end up somewhere you don’t want to be.
I know! But the good thing about dirtbikes is that it is mechanical. You can fix most problems with tools. The confidence on the other hand…

I’m not trying to pressure anyone to ride anything they dont feel confident on, but tools can fix mechanical stuff. The rest is up to you. Worst case scenario is one lap and switch over to whatever cartridge you want. Best case is you wont need to spend money on something.
MX558
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MX558 4/14/2022 5:55pm
4/14/2022 5:55pm
wrc777 wrote:
So you are running mousses instead of tubes too right? Same (or cheaper) valve in every tube.
It's way different getting a flat tire vs a fork callapsing . What more expensive the spring conversion or hospital bill ? Like I said it happened on my 17 and had to have surgery for a torn tricep and 4 months of not riding or doing any lifting
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wrc777 4/14/2022 7:12pm
4/14/2022 7:12pm
wrc777 wrote:
So you are running mousses instead of tubes too right? Same (or cheaper) valve in every tube.
MX558 wrote:
It's way different getting a flat tire vs a fork callapsing . What more expensive the spring conversion or hospital bill ? Like I said it...
It's way different getting a flat tire vs a fork callapsing . What more expensive the spring conversion or hospital bill ? Like I said it happened on my 17 and had to have surgery for a torn tricep and 4 months of not riding or doing any lifting
What was the fork that failed and what failed?
MX558
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MX558 4/15/2022 6:53pm
4/15/2022 6:53pm
wrc777 wrote:
So you are running mousses instead of tubes too right? Same (or cheaper) valve in every tube.
MX558 wrote:
It's way different getting a flat tire vs a fork callapsing . What more expensive the spring conversion or hospital bill ? Like I said it...
It's way different getting a flat tire vs a fork callapsing . What more expensive the spring conversion or hospital bill ? Like I said it happened on my 17 and had to have surgery for a torn tricep and 4 months of not riding or doing any lifting
wrc777 wrote:
What was the fork that failed and what failed?
Probably Schrader valve but like I said not taking any chances I'll just go kyb's spring fork
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Matt Fisher 4/17/2022 2:51pm
4/17/2022 2:51pm
MX558 wrote:
It's way different getting a flat tire vs a fork callapsing . What more expensive the spring conversion or hospital bill ? Like I said it...
It's way different getting a flat tire vs a fork callapsing . What more expensive the spring conversion or hospital bill ? Like I said it happened on my 17 and had to have surgery for a torn tricep and 4 months of not riding or doing any lifting
wrc777 wrote:
What was the fork that failed and what failed?
MX558 wrote:
Probably Schrader valve but like I said not taking any chances I'll just go kyb's spring fork
Look into the Blackjack cartridges. Very nice stuff, and easy to remove when you sell the bike.
MX558
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MX558 4/17/2022 7:04pm
4/17/2022 7:04pm
wrc777 wrote:
What was the fork that failed and what failed?
MX558 wrote:
Probably Schrader valve but like I said not taking any chances I'll just go kyb's spring fork
Matt Fisher wrote:
Look into the Blackjack cartridges. Very nice stuff, and easy to remove when you sell the bike.
I thought about that but not much reviews on them . I rode a bike with the lucky carbons and thought they were ok but nowhere near KYB or showa stuff . Plus my suspension shop TZR is a master with KYB
gkelm
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gkelm 4/22/2022 7:54pm
4/22/2022 7:54pm
Happened to me…replaced the stem in the valve. Done. KYB would be nice too, all it takes is cash!
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