XACT air forks (2021 GasGas 450) - too stiff ?

DC193
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Anyone else running the XACT air forks finding them very stiff ?

my 2021 MC450 has 12 hours on it now. I've replaced the rear 42 spring with a 45, as i had read that they are soft, and even with the stiffer spring (stock clicker settings) i can just bottom out the rear, but the forks seem way stiff to me.

I've reduced air pressure down to 140, and reduced comp clickers, but still get a very solid feel from them and cant seem to bottom them out at all.

Should i go less than 140psi ? how low is too low ?

just interested on how others have found these forks.
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yz133rider
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6/8/2022 5:37pm
I liked mine at 152 psi. What weight, speed and type of track?
DC193
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6/8/2022 6:09pm
yz133rider wrote:
I liked mine at 152 psi. What weight, speed and type of track?

88kg, vet rider, medium to hardpack track, quite a few jumps. not as fast as the racers of course, but would say i'm towards the quickest of the weekend warriors, for whats its worth.

Would say i'm landing from 6-7 feet height above ground on the biggest jumps. I do get a very 'slap' feel when landing from the biggest jumps, like the fork has compressed to a certain point, then just stopped compressing.

when i ran 150psi i could feel EVERY bump.
ElliotB16
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6/9/2022 4:37am
With your weight you should be closer to 155psi. If it’s too soft you could be running too low in the stroke causing harshness.

Factory connection did a spring conversion on mine and is much better. That may be an option for you
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wrc777
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6/9/2022 5:55am
yz133rider wrote:
I liked mine at 152 psi. What weight, speed and type of track?
DC193 wrote:
88kg, vet rider, medium to hardpack track, quite a few jumps. not as fast as the racers of course, but would say i'm towards the quickest...

88kg, vet rider, medium to hardpack track, quite a few jumps. not as fast as the racers of course, but would say i'm towards the quickest of the weekend warriors, for whats its worth.

Would say i'm landing from 6-7 feet height above ground on the biggest jumps. I do get a very 'slap' feel when landing from the biggest jumps, like the fork has compressed to a certain point, then just stopped compressing.

when i ran 150psi i could feel EVERY bump.
You are probably going to get a slap feel from bigger jumps although the 2021 and newer are a lot better than 202o0 and older. As others said you could be too low on pressure. Try higher pressure and then maybe back off the compression clicker until you don't feel every bump on the track. Are you using a wire tie or the included o-ring to check travel? Don't forget to bleed the out chambers too.

A different handlebar will help with the slap. The stock one is about as stiff as you can get without a crossbar. Try a Protaper EVO or ACF. Even a Renthal Fatbar will help.
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The Shop

Moto520
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6/9/2022 9:26am
Give the bike more time to break in before doing anything drastic. Depending on how hard you ride....it can take up to 20 hours for the bike to feel right.
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Leeham
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6/9/2022 10:25am
Make sure that front end is lined up and even. Forks even height, triple clamps torqued to right values. Could be binding up.

Other than that PSI is something you should play with. Too low and you blow past the initial valving. Or just get springs.
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aees
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6/9/2022 2:52pm Edited Date/Time 6/10/2022 9:38pm
Make sure you torque the linkage and swingarm 60/100nm (and recheck sag). Has a big effect if you tighten it for hand. Also should be 142mm between chrome fork legs to be fully aligned. Bouncing on the ground and snapping front brake can still put you up to 2mm off on the aligning.
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DC193
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6/9/2022 4:13pm
yz133rider wrote:
I liked mine at 152 psi. What weight, speed and type of track?
DC193 wrote:
88kg, vet rider, medium to hardpack track, quite a few jumps. not as fast as the racers of course, but would say i'm towards the quickest...

88kg, vet rider, medium to hardpack track, quite a few jumps. not as fast as the racers of course, but would say i'm towards the quickest of the weekend warriors, for whats its worth.

Would say i'm landing from 6-7 feet height above ground on the biggest jumps. I do get a very 'slap' feel when landing from the biggest jumps, like the fork has compressed to a certain point, then just stopped compressing.

when i ran 150psi i could feel EVERY bump.
wrc777 wrote:
You are probably going to get a slap feel from bigger jumps although the 2021 and newer are a lot better than 202o0 and older. As...
You are probably going to get a slap feel from bigger jumps although the 2021 and newer are a lot better than 202o0 and older. As others said you could be too low on pressure. Try higher pressure and then maybe back off the compression clicker until you don't feel every bump on the track. Are you using a wire tie or the included o-ring to check travel? Don't forget to bleed the out chambers too.

A different handlebar will help with the slap. The stock one is about as stiff as you can get without a crossbar. Try a Protaper EVO or ACF. Even a Renthal Fatbar will help.

thanks for the advice mate - i didn't know about the 'included o-ring' - should this have come with the bike brand new ? I'm in Australia, don't know if that makes a difference. I'll up the pressure and down the clickers and try the zip-tie trick around the tubes. i assume you mean bleed the air release at the top of the forks each ride, and i do that.
DC193
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6/9/2022 4:14pm
Moto520 wrote:
Give the bike more time to break in before doing anything drastic. Depending on how hard you ride....it can take up to 20 hours for the...
Give the bike more time to break in before doing anything drastic. Depending on how hard you ride....it can take up to 20 hours for the bike to feel right.
thanks, yes i didn't want to make drastic changes too soon, so i thought i'd see what others experiences were.
DC193
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6/9/2022 4:15pm
Leeham wrote:
Make sure that front end is lined up and even. Forks even height, triple clamps torqued to right values. Could be binding up. Other than that...
Make sure that front end is lined up and even. Forks even height, triple clamps torqued to right values. Could be binding up.

Other than that PSI is something you should play with. Too low and you blow past the initial valving. Or just get springs.
thanks, will re-check everything.
wrc777
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6/9/2022 4:17pm
DC193 wrote:
88kg, vet rider, medium to hardpack track, quite a few jumps. not as fast as the racers of course, but would say i'm towards the quickest...

88kg, vet rider, medium to hardpack track, quite a few jumps. not as fast as the racers of course, but would say i'm towards the quickest of the weekend warriors, for whats its worth.

Would say i'm landing from 6-7 feet height above ground on the biggest jumps. I do get a very 'slap' feel when landing from the biggest jumps, like the fork has compressed to a certain point, then just stopped compressing.

when i ran 150psi i could feel EVERY bump.
wrc777 wrote:
You are probably going to get a slap feel from bigger jumps although the 2021 and newer are a lot better than 202o0 and older. As...
You are probably going to get a slap feel from bigger jumps although the 2021 and newer are a lot better than 202o0 and older. As others said you could be too low on pressure. Try higher pressure and then maybe back off the compression clicker until you don't feel every bump on the track. Are you using a wire tie or the included o-ring to check travel? Don't forget to bleed the out chambers too.

A different handlebar will help with the slap. The stock one is about as stiff as you can get without a crossbar. Try a Protaper EVO or ACF. Even a Renthal Fatbar will help.
DC193 wrote:
thanks for the advice mate - i didn't know about the 'included o-ring' - should this have come with the bike brand new ? I'm in...

thanks for the advice mate - i didn't know about the 'included o-ring' - should this have come with the bike brand new ? I'm in Australia, don't know if that makes a difference. I'll up the pressure and down the clickers and try the zip-tie trick around the tubes. i assume you mean bleed the air release at the top of the forks each ride, and i do that.
Yes on bleeding the forks. The orings are red and come installed at the bottom of the fork legs. You just slide one or both up and it works like the zip Ty for checking how much travel you used. MXA will tell you to adjust air pressure until you use all but 1.5” (about 38mm) of travel.
DC193
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6/9/2022 5:36pm
wrc777 wrote:
Yes on bleeding the forks. The orings are red and come installed at the bottom of the fork legs. You just slide one or both up...
Yes on bleeding the forks. The orings are red and come installed at the bottom of the fork legs. You just slide one or both up and it works like the zip Ty for checking how much travel you used. MXA will tell you to adjust air pressure until you use all but 1.5” (about 38mm) of travel.

you champion - i hadn't noticed the red rings, will definately use this, thanks for the info.
soggy
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6/9/2022 6:15pm
Checking your fork alignment too while your at it. Bunch of good videos out there to reference.
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StevenMX
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6/9/2022 7:19pm Edited Date/Time 6/9/2022 7:19pm
[url=]https://www.youtube.com/watch?v=9nWf18AhTOk[/url]

Great video for fork alignment, every time I do it now and especially the first time the bikes front felt very plush/no binding. As others mentioned above, do this in addition to the PSI increase, back out compression and check the travel you are using!
DC193
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6/9/2022 10:03pm
StevenMX wrote:
[url=]https://www.youtube.com/watch?v=9nWf18AhTOk[/url] Great video for fork alignment, every time I do it now and especially the first time the bikes front felt very plush/no binding. As others...
[url=]https://www.youtube.com/watch?v=9nWf18AhTOk[/url]

Great video for fork alignment, every time I do it now and especially the first time the bikes front felt very plush/no binding. As others mentioned above, do this in addition to the PSI increase, back out compression and check the travel you are using!

Brilliant, thanks !
DC193
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6/10/2022 6:39pm Edited Date/Time 6/10/2022 6:43pm
StevenMX wrote:
[url=]https://www.youtube.com/watch?v=9nWf18AhTOk[/url] Great video for fork alignment, every time I do it now and especially the first time the bikes front felt very plush/no binding. As others...
[url=]https://www.youtube.com/watch?v=9nWf18AhTOk[/url]

Great video for fork alignment, every time I do it now and especially the first time the bikes front felt very plush/no binding. As others mentioned above, do this in addition to the PSI increase, back out compression and check the travel you are using!
I noticed he put the axle through to check for easy slide movement, mine is very hard to slide through.

Cleaned out my lug bores with scotchbrite, no improvement. Notice when I moved my brake side fork up in the clamps it improved but to get easy sliding, my brake side fork was half a notch up higher than the other side - video notes this could be an internal fork issue, but would running one fork higher than the other, to get the axle correct, be ok to ride with ?
StevenMX
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6/10/2022 6:53pm
Take everything off (forks, bars, loosen steering stem, etc.)... check front forks (fully extend dampening side/check range of motion)... I noticed on my 21 250SX when I did it the first time one fork was EVVVER so slightly different height on the fork lines from the other. However my axle was buttery smooth with noooo resistance. I rode it like this and it felt great. I've done this alignment on my new 22.5 FE 250SXF and both forks are aligned (same line across both forks) with pretty good flow through the axle block. It may help to do what he does in the video once you reinstall the forks and only tighten down 1 lower clamp bolt each, move the left fork leg when putting axle through and wiggle the left fork/give it some push/pull to find it's relaxed position. (My brake side/left fork with air was higher as well on the 250sx). Try adjusting again, go through it, and then give it a ride and see the difference vs putting forks at equal height with the axle not being smooth. I can't say if your fork has anything wrong internally, just make sure when you are doing this the front wheel is entirely off the ground and the forks are extended all the way.
6/10/2022 8:38pm
A friend of mine runs a local suspension company; he's pulled a few forks apart on the newer KTM triplets only to find them really low on oil, really strange shim configurations, and one that was missing a couple of minor parts. Most of the bikes are fine, but a few appear to have been built by not so skilled labor.
The most logical reasoning I've heard is Covid cut down on the skilled, experienced labor at the factory and the QC took a dive.
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Jensenyo
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6/11/2022 12:03am
Sounds to me like you have too light rear spring. I have found a good balance on my 250 sx-f 2021 with an 48nm spring.I weigh 82 kg without gear, preload about 10mm with 38-39mm static sag and about 105 rider sag.

I run forks standard height, and have been trying pressures from 9.8-11bar (10.4 stock) On motocross track I have been most happy with 10.6-10.8 bar pressure, got recomended to increase oil to 270 ml each leg too. The fork is not the plushest , especially on small chop while accelerating but it holds up well into rough brakingbumps .I can also not that im no fast pro rider , would say Vet B-C rider soon 40 years old Smile

Clickers have been mostly stock except Rebound rear that I have gone in 3 clicks to 12.

Good luck and keep us updated on the progress!
1
DC193
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6/11/2022 2:16am
StevenMX wrote:
Take everything off (forks, bars, loosen steering stem, etc.)... check front forks (fully extend dampening side/check range of motion)... I noticed on my 21 250SX when...
Take everything off (forks, bars, loosen steering stem, etc.)... check front forks (fully extend dampening side/check range of motion)... I noticed on my 21 250SX when I did it the first time one fork was EVVVER so slightly different height on the fork lines from the other. However my axle was buttery smooth with noooo resistance. I rode it like this and it felt great. I've done this alignment on my new 22.5 FE 250SXF and both forks are aligned (same line across both forks) with pretty good flow through the axle block. It may help to do what he does in the video once you reinstall the forks and only tighten down 1 lower clamp bolt each, move the left fork leg when putting axle through and wiggle the left fork/give it some push/pull to find it's relaxed position. (My brake side/left fork with air was higher as well on the 250sx). Try adjusting again, go through it, and then give it a ride and see the difference vs putting forks at equal height with the axle not being smooth. I can't say if your fork has anything wrong internally, just make sure when you are doing this the front wheel is entirely off the ground and the forks are extended all the way.

Have taken all bits apart and rebuilt exactly as per the video (with brake side fork slightly higher to allow the easy slide of the axle)

Ride the day after tomorrow, we’ll see how it goes.

DC193
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6/11/2022 2:19am
Jensenyo wrote:
Sounds to me like you have too light rear spring. I have found a good balance on my 250 sx-f 2021 with an 48nm spring.I weigh...
Sounds to me like you have too light rear spring. I have found a good balance on my 250 sx-f 2021 with an 48nm spring.I weigh 82 kg without gear, preload about 10mm with 38-39mm static sag and about 105 rider sag.

I run forks standard height, and have been trying pressures from 9.8-11bar (10.4 stock) On motocross track I have been most happy with 10.6-10.8 bar pressure, got recomended to increase oil to 270 ml each leg too. The fork is not the plushest , especially on small chop while accelerating but it holds up well into rough brakingbumps .I can also not that im no fast pro rider , would say Vet B-C rider soon 40 years old Smile

Clickers have been mostly stock except Rebound rear that I have gone in 3 clicks to 12.

Good luck and keep us updated on the progress!

Yeah, I had the 48 spring on my previous bike (16 husky 350). Glad at least that I changed the 42 for the 45, but yes the 48 might be the next change (or lose a few pounds !)

Have noticed my sag has increased, I thought I had set for 105 but rechecked and showing 108mm, so will adjust this too.

Will report back after the next ride.
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CarlinoJoeVideo
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6/11/2022 3:12am
Recheck the fork clamp bolts torque. Maybe who ever built the bike squeezed the fork tubes?
StevenMX
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6/11/2022 10:30am
Curious to see how it goes DC, let us know.
DC193
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6/19/2022 2:19pm
Ok, after a day out riding, fork action was definately improved by setting the form heights based on having the free axle movement (brake side fork slightly higher than the other).

The red rings around the forks are a brilliant idea. Realised quickly I was bottoming the rings down to less than an inch of travel. Ended up increasing stiffness to 152psi.

I'll have to do another 'test' day to confirm. I had to increase comp clickers two clicks late in the day, but noticed when I got home that fork pressure was 138psi. I lost the little cap so I think I've bumped the valve but not sure whether I did this when putting the bike on the trailer home or whether I did my last ride of the day with the lower fork pressure.

I also measured the big jump at my local track that I'm using the full suspension travel - just on 90 feet.

Further updates to come after the next ride.
1
StevenMX
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6/19/2022 8:34pm
I ran my 21 air forks at 151 psi and liked it there (backing out compression to get the softness in chop but hold up you need by upping air pressure). I also use to have motion pro bleeders for the forks but I took them off and went to stock screws as they bled/didn't keep air in...Cap on might help, could also lose air when you attach the air pump to the fork to check as well if you do it at an awkward angle, I noticed my pump now is a little worn and doesn't seal perfectly unless I am straight on the valve, not a bike issue just the little pump being used 1,000 times.
DC193
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6/19/2022 8:53pm
StevenMX wrote:
I ran my 21 air forks at 151 psi and liked it there (backing out compression to get the softness in chop but hold up you...
I ran my 21 air forks at 151 psi and liked it there (backing out compression to get the softness in chop but hold up you need by upping air pressure). I also use to have motion pro bleeders for the forks but I took them off and went to stock screws as they bled/didn't keep air in...Cap on might help, could also lose air when you attach the air pump to the fork to check as well if you do it at an awkward angle, I noticed my pump now is a little worn and doesn't seal perfectly unless I am straight on the valve, not a bike issue just the little pump being used 1,000 times.

thanks. What shock spring rate are you using ? I changed the stock 42 to a 45, but wondering whether a 48 might be better. I run 105 sag and two clicks stiffer comp on the shock, and not seeing any signs of bottoming out.
yz133rider
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6/20/2022 3:50am Edited Date/Time 6/20/2022 3:51am
If it was much warmer during the day when you set the pressure than when you checked later that night - that could be the reason the pressure dropped.

If you set it early morning when it’s cool still and the temp rises a bunch by midday you’ll see the pressure is higher than when you set it.

I wouldn’t go stiffer on the shock spring. But I also like the 4.2 rear somehow and I’m 200lbs. I’ve tried 4.5 and 4.8 and for my riding the 4.2 works the best for me.
1
aees
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6/24/2022 2:38am
Just a comment i saw now. If you have 10mm preload on 48nm and get 39mm sag, something is wrong. You should be at around 5-6mm.

Either you are low on gas in shock reservoir, or linkage or swingarm is not properly torqued. 100nm swingarm, 60nm for all shock bolts + linkage bolts. Make sure the upper swingarm bolt for linkage does not bind, so check it runs free after torquing that one.
StevenMX
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6/24/2022 1:01pm
StevenMX wrote:
I ran my 21 air forks at 151 psi and liked it there (backing out compression to get the softness in chop but hold up you...
I ran my 21 air forks at 151 psi and liked it there (backing out compression to get the softness in chop but hold up you need by upping air pressure). I also use to have motion pro bleeders for the forks but I took them off and went to stock screws as they bled/didn't keep air in...Cap on might help, could also lose air when you attach the air pump to the fork to check as well if you do it at an awkward angle, I noticed my pump now is a little worn and doesn't seal perfectly unless I am straight on the valve, not a bike issue just the little pump being used 1,000 times.
DC193 wrote:
thanks. What shock spring rate are you using ? I changed the stock 42 to a 45, but wondering whether a 48 might be better. I...

thanks. What shock spring rate are you using ? I changed the stock 42 to a 45, but wondering whether a 48 might be better. I run 105 sag and two clicks stiffer comp on the shock, and not seeing any signs of bottoming out.
I'm on the stock 42NM on my 22 FE 250SX-F but a 45Nm on my revalved Factory connection shock for the 21 ktm 250sx. I need to up my spring rate on the 250sx-f as my sag is low (107-108 right now) and I have it torqued down quite a bit. I'm 5' 9" and 170lbs for reference... I really liked the 45Nm shock spring myself as it will not squat or bounce in corners as easily. Balance of the bike was better for me with that and my skill/weight.

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