2023 KTM 350 SXF or 2023 FC 350 handling issues?

TahoeVetMX
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271
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9/5/2021
Location
Las Vegas, NV, USA
6/22/2024 9:27pm
lowmass wrote:
Thanks for responding. So heres my thing... Im comming off a 2022 sxf and now on a 2025 350 SXF. This new chassis imo runs rear...

Thanks for responding. So heres my thing...

Im comming off a 2022 sxf and now on a 2025 350 SXF. This new chassis imo runs rear high. Ive never been comfortable on any bike that is setup this way. By the time ya run enough pressure in forks to balance out with the tall running rear you end up with a very tall bike. Im almost 6 feet so seat height not an issue BUT a tall bike does not handle well in dry hard or slik conditions. Too tricky at corner entrance. So To get a balanced chassis and a reasonably low center of gravity I needed sag at about 115mm. This however results in excessive free sag of 50mm SO I installed a shock shortening spacer that lowered rear of seat about 10mm. This worked well and now can run 105mm sag again and get a level chassis. However this shock and link seem a bit backwards in that the first half of travel is a bit too stiff and the last half of travel is a bit too soft. I believe the best approach would be a more progressive link (softer rate in first half and stiffer rate in last half). 

Anyway it sounds to me youve landed in the same place and I just wanted to hear an update on how its going and what you have found now with more time

TahoeVetMX wrote:
Yes, similar story many have had to deal with.  I am 6ft and 190 with gear.   A couple of things.  1)  the new gen frame is...

Yes, similar story many have had to deal with.  I am 6ft and 190 with gear.   A couple of things.  1)  the new gen frame is very sensitive on balance.  If you are off you feel it in the hands.   Meaning if the rear has too much pressure on the front end the vibration in the hands gets worse.  Running the forks long certainly helps this issue and also the 23.5 clamps also helps.   2)  Buy those 10mm down 10mm back foot pegs!   That also helps a great deal for the taller riders.   3)  Progressive linkage helps with that sag issue.   However, my opinion is to run a spring softer than you would normally be told to do.   I normally was on a 4.8  but with a progressive linkage I am on a 4.6 rear spring.  It works for me very well and maybe it takes some stiffness out of the bike.   Yes, there are other things you can buy but those were the best overall.

lowmass wrote:
Thanks yes very sensitive. When close to sweet spot I can easily feel 1mm sag changes Do you have a link to those pegs? I considered...

Thanks

yes very sensitive. When close to sweet spot I can easily feel 1mm sag changes

Do you have a link to those pegs?

I considered a lighter spring but I am using everything it has now so not sure thats a good option for me

A coil and some valving work out front I hope will help match the rears action better. I need a stiffer front to get a level chassis but not the harshness the AER has at higher pressures.

No one has a link available for the 2025 yet. The bolt between arm and knuckle is smaller on the 25 than on the 23-24. However Luxon is sending me a proto knuckle to test. Plan to test this over next few weeks and maybe do some shim work as well

 

1
GPrider
Posts
772
Joined
4/10/2014
Location
La Mesa, CA, USA
6/24/2024 9:15am
lowmass wrote:
Thanks for responding. So heres my thing... Im comming off a 2022 sxf and now on a 2025 350 SXF. This new chassis imo runs rear...

Thanks for responding. So heres my thing...

Im comming off a 2022 sxf and now on a 2025 350 SXF. This new chassis imo runs rear high. Ive never been comfortable on any bike that is setup this way. By the time ya run enough pressure in forks to balance out with the tall running rear you end up with a very tall bike. Im almost 6 feet so seat height not an issue BUT a tall bike does not handle well in dry hard or slik conditions. Too tricky at corner entrance. So To get a balanced chassis and a reasonably low center of gravity I needed sag at about 115mm. This however results in excessive free sag of 50mm SO I installed a shock shortening spacer that lowered rear of seat about 10mm. This worked well and now can run 105mm sag again and get a level chassis. However this shock and link seem a bit backwards in that the first half of travel is a bit too stiff and the last half of travel is a bit too soft. I believe the best approach would be a more progressive link (softer rate in first half and stiffer rate in last half). 

Anyway it sounds to me youve landed in the same place and I just wanted to hear an update on how its going and what you have found now with more time

TahoeVetMX wrote:
Yes, similar story many have had to deal with.  I am 6ft and 190 with gear.   A couple of things.  1)  the new gen frame is...

Yes, similar story many have had to deal with.  I am 6ft and 190 with gear.   A couple of things.  1)  the new gen frame is very sensitive on balance.  If you are off you feel it in the hands.   Meaning if the rear has too much pressure on the front end the vibration in the hands gets worse.  Running the forks long certainly helps this issue and also the 23.5 clamps also helps.   2)  Buy those 10mm down 10mm back foot pegs!   That also helps a great deal for the taller riders.   3)  Progressive linkage helps with that sag issue.   However, my opinion is to run a spring softer than you would normally be told to do.   I normally was on a 4.8  but with a progressive linkage I am on a 4.6 rear spring.  It works for me very well and maybe it takes some stiffness out of the bike.   Yes, there are other things you can buy but those were the best overall.

lowmass wrote:
Thanks yes very sensitive. When close to sweet spot I can easily feel 1mm sag changes Do you have a link to those pegs? I considered...

Thanks

yes very sensitive. When close to sweet spot I can easily feel 1mm sag changes

Do you have a link to those pegs?

I considered a lighter spring but I am using everything it has now so not sure thats a good option for me

A coil and some valving work out front I hope will help match the rears action better. I need a stiffer front to get a level chassis but not the harshness the AER has at higher pressures.

No one has a link available for the 2025 yet. The bolt between arm and knuckle is smaller on the 25 than on the 23-24. However Luxon is sending me a proto knuckle to test. Plan to test this over next few weeks and maybe do some shim work as well

 

REP has the 25 linkage, bolt it on and your problems will go away!!

 

lowmass
Posts
190
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6/19/2024
Location
LANSING, NY, USA
6/24/2024 9:50am Edited Date/Time 6/24/2024 10:00am
TahoeVetMX wrote:
Yes, similar story many have had to deal with.  I am 6ft and 190 with gear.   A couple of things.  1)  the new gen frame is...

Yes, similar story many have had to deal with.  I am 6ft and 190 with gear.   A couple of things.  1)  the new gen frame is very sensitive on balance.  If you are off you feel it in the hands.   Meaning if the rear has too much pressure on the front end the vibration in the hands gets worse.  Running the forks long certainly helps this issue and also the 23.5 clamps also helps.   2)  Buy those 10mm down 10mm back foot pegs!   That also helps a great deal for the taller riders.   3)  Progressive linkage helps with that sag issue.   However, my opinion is to run a spring softer than you would normally be told to do.   I normally was on a 4.8  but with a progressive linkage I am on a 4.6 rear spring.  It works for me very well and maybe it takes some stiffness out of the bike.   Yes, there are other things you can buy but those were the best overall.

lowmass wrote:
Thanks yes very sensitive. When close to sweet spot I can easily feel 1mm sag changes Do you have a link to those pegs? I considered...

Thanks

yes very sensitive. When close to sweet spot I can easily feel 1mm sag changes

Do you have a link to those pegs?

I considered a lighter spring but I am using everything it has now so not sure thats a good option for me

A coil and some valving work out front I hope will help match the rears action better. I need a stiffer front to get a level chassis but not the harshness the AER has at higher pressures.

No one has a link available for the 2025 yet. The bolt between arm and knuckle is smaller on the 25 than on the 23-24. However Luxon is sending me a proto knuckle to test. Plan to test this over next few weeks and maybe do some shim work as well

 

GPrider wrote:

REP has the 25 linkage, bolt it on and your problems will go away!!

 

Maybe....

Ive been back n forth with REP on this from the beginning. They were very helpful and put up with my multiple questions like pros with patience. A rare combination Wink

They said there seems to be two camps on this. One type of rider is fine with the tall rear end and the other type wants a lower rear end. They said I seem to be in the latter camp AND the REP link actually raises the rear of an already tall bike another 5mm so not sure this is best route for me? . In my case they suggested shortening the shock to get the rear ridding where I want, then adjust from there. In my case ( with stock link anyway) that came to a 3.7mm spacer in shock lowering rear of seat about 10mm. Now I was able to run 105 sag and get 40mm free sag with the rear where I like it, instead of running 115 sag and 50mm free sag ya get from just blowing the sag out . Much  better with the spacers now  and similar ride height in turns as my 2022 SXF chassis.

This is the bang for buck "quick fix" with its inherent limitations in that ya still have a link thats a bit harsh in first part of stroke and a bit soft in last part .

They  said I can run the REP link with the lowering spacers as well and gain the benefit of the steeper rising rate in last half of stroke that's  needed BUT with the lowering spacers you've rotated the link a bit and will be giving up part of the less steep rising rate plushness in the first half of the stroke.  Still some improvement over the stock link and I may ultimately go that route.

Perhaps important to point out... I suspect REP has valving front and rear figured out that will give a more level dynamic ride height on track with their link  and get the full benafit of its profile but at the moment the 5mm increase in rear height their link gives  has me a bit shy of shelling out a bunch to find out if I would e ok with that setup?

For now I have opportunity to test Luxon's soon to be released Knuckle that's also softer in first half and stiffer in last half. That arrived today and I plan to start testing  this weekend. 

Plenty of work to do for now ha

 

AssangeMX
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Location
Belmarsh, CA, USA
6/25/2024 10:29am

For those that went to 14 by 52 or 53 gearing, what chain length did you use and did it help free up rear end?

The Shop

3/22/2025 3:37pm

Reviving an older thread. 

How are you guys doing with setup now? Curious what sag guys with the rep linkage are running on the 23/24. I’m running 109mm now with my forks on the second line (kyb cartridges) and can’t really get much front end feel/traction. Logically I would run less sag, but my rear already feels super high. Running a 4.9nm at 200lbs. Static around 38mm

aees
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2787
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Location
USA
3/22/2025 3:57pm Edited Date/Time 3/22/2025 3:57pm
Reviving an older thread. How are you guys doing with setup now? Curious what sag guys with the rep linkage are running on the 23/24. I’m running...

Reviving an older thread. 

How are you guys doing with setup now? Curious what sag guys with the rep linkage are running on the 23/24. I’m running 109mm now with my forks on the second line (kyb cartridges) and can’t really get much front end feel/traction. Logically I would run less sag, but my rear already feels super high. Running a 4.9nm at 200lbs. Static around 38mm

40/110 most I know run. 

I know some that also feel it is the rider cockpit that is off, not always the suspension or chassi balance. Keep forks at second line and raise the bar 5-10mm instead. 

Sag at 40/110 you can also close the low speed comp on shock. That has big impact on front end traction. You can try go out on HSC instead if it gets harsh and stiff and to maintain balance. 

You can also try dropping the reseervoir pressure to 8 or 9 bar. You will have to increase preload to get same sag. Increase of preload and reduce pressure will give your more front end traction but maintain balance. Higher reservoir pressure give a more diffuse feeling but slightly plusher ride. This is beside the point of keeping cavation right. 

Also, running Xact Pro shock, it's easier to drop sag but still get good cornering and traction in front by stiffening/closing the high speed rebound at the same time. You lose HSR when backing of preload and using just the LSR on stock shock affects to much other areas. 

3/22/2025 4:04pm
Reviving an older thread. How are you guys doing with setup now? Curious what sag guys with the rep linkage are running on the 23/24. I’m running...

Reviving an older thread. 

How are you guys doing with setup now? Curious what sag guys with the rep linkage are running on the 23/24. I’m running 109mm now with my forks on the second line (kyb cartridges) and can’t really get much front end feel/traction. Logically I would run less sag, but my rear already feels super high. Running a 4.9nm at 200lbs. Static around 38mm

aees wrote:
40/110 most I know run. I know some that also feel it is the rider cockpit that is off, not always the suspension or chassi balance. Keep...

40/110 most I know run. 

I know some that also feel it is the rider cockpit that is off, not always the suspension or chassi balance. Keep forks at second line and raise the bar 5-10mm instead. 

Sag at 40/110 you can also close the low speed comp on shock. That has big impact on front end traction. You can try go out on HSC instead if it gets harsh and stiff and to maintain balance. 

You can also try dropping the reseervoir pressure to 8 or 9 bar. You will have to increase preload to get same sag. Increase of preload and reduce pressure will give your more front end traction but maintain balance. Higher reservoir pressure give a more diffuse feeling but slightly plusher ride. This is beside the point of keeping cavation right. 

Also, running Xact Pro shock, it's easier to drop sag but still get good cornering and traction in front by stiffening/closing the high speed rebound at the same time. You lose HSR when backing of preload and using just the LSR on stock shock affects to much other areas. 

Perfect, I will try that out. I was thinking I’d mess with the hsc next to see if that helps. 
I’m also running 3mm preload on the forks, that’s the only preload I’ve tried since the conversion. I believe I was running 0-1mm on the cv and 6500s, so I may drop that down

aees
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2787
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USA
3/22/2025 4:16pm
Reviving an older thread. How are you guys doing with setup now? Curious what sag guys with the rep linkage are running on the 23/24. I’m running...

Reviving an older thread. 

How are you guys doing with setup now? Curious what sag guys with the rep linkage are running on the 23/24. I’m running 109mm now with my forks on the second line (kyb cartridges) and can’t really get much front end feel/traction. Logically I would run less sag, but my rear already feels super high. Running a 4.9nm at 200lbs. Static around 38mm

aees wrote:
40/110 most I know run. I know some that also feel it is the rider cockpit that is off, not always the suspension or chassi balance. Keep...

40/110 most I know run. 

I know some that also feel it is the rider cockpit that is off, not always the suspension or chassi balance. Keep forks at second line and raise the bar 5-10mm instead. 

Sag at 40/110 you can also close the low speed comp on shock. That has big impact on front end traction. You can try go out on HSC instead if it gets harsh and stiff and to maintain balance. 

You can also try dropping the reseervoir pressure to 8 or 9 bar. You will have to increase preload to get same sag. Increase of preload and reduce pressure will give your more front end traction but maintain balance. Higher reservoir pressure give a more diffuse feeling but slightly plusher ride. This is beside the point of keeping cavation right. 

Also, running Xact Pro shock, it's easier to drop sag but still get good cornering and traction in front by stiffening/closing the high speed rebound at the same time. You lose HSR when backing of preload and using just the LSR on stock shock affects to much other areas. 

Perfect, I will try that out. I was thinking I’d mess with the hsc next to see if that helps. I’m also running 3mm preload on the...

Perfect, I will try that out. I was thinking I’d mess with the hsc next to see if that helps. 
I’m also running 3mm preload on the forks, that’s the only preload I’ve tried since the conversion. I believe I was running 0-1mm on the cv and 6500s, so I may drop that down

KYB should be 3-4mm, don't dropp below that. CV/6500 built differently so they can handle it. 

Go max out HSC, go in 5-6 clicks on lsc instead and try that. 

1
3/22/2025 4:19pm
aees wrote:
40/110 most I know run. I know some that also feel it is the rider cockpit that is off, not always the suspension or chassi balance. Keep...

40/110 most I know run. 

I know some that also feel it is the rider cockpit that is off, not always the suspension or chassi balance. Keep forks at second line and raise the bar 5-10mm instead. 

Sag at 40/110 you can also close the low speed comp on shock. That has big impact on front end traction. You can try go out on HSC instead if it gets harsh and stiff and to maintain balance. 

You can also try dropping the reseervoir pressure to 8 or 9 bar. You will have to increase preload to get same sag. Increase of preload and reduce pressure will give your more front end traction but maintain balance. Higher reservoir pressure give a more diffuse feeling but slightly plusher ride. This is beside the point of keeping cavation right. 

Also, running Xact Pro shock, it's easier to drop sag but still get good cornering and traction in front by stiffening/closing the high speed rebound at the same time. You lose HSR when backing of preload and using just the LSR on stock shock affects to much other areas. 

Perfect, I will try that out. I was thinking I’d mess with the hsc next to see if that helps. I’m also running 3mm preload on the...

Perfect, I will try that out. I was thinking I’d mess with the hsc next to see if that helps. 
I’m also running 3mm preload on the forks, that’s the only preload I’ve tried since the conversion. I believe I was running 0-1mm on the cv and 6500s, so I may drop that down

aees wrote:
KYB should be 3-4mm, don't dropp below that. CV/6500 built differently so they can handle it. Go max out HSC, go in 5-6 clicks on lsc instead...

KYB should be 3-4mm, don't dropp below that. CV/6500 built differently so they can handle it. 

Go max out HSC, go in 5-6 clicks on lsc instead and try that. 

Will do, I appreciate it 

121x
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196
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3/9/2022
Location
Ontario, CA
7/5/2025 2:00pm

Any updates on how things played out after the recommended adjustments?

7/5/2025 3:19pm
121x wrote:

Any updates on how things played out after the recommended adjustments?

It’s been too hot in the desert to really ride, but I have been making some changes. 
Recent shock changes : lainer compression adjuster and main piston, shortened shock 2mm (dropped rear of bike 5mm)

Still playing with valving on the kyb cartridges, installed Enzo spring tubes yesterday. Forks feel busy now and a little too soft in top and mid stroke, will be making adjustments to valving soon. 

Overall the balance and front end feel are improved and I feel I can get the rear pretty good once I get to the track. One thing I’ve learned is what feels good in my local terrain does not translate well to Glen Helen. Like at all lol

121x
Posts
196
Joined
3/9/2022
Location
Ontario, CA
7/6/2025 12:38pm
121x wrote:

Any updates on how things played out after the recommended adjustments?

It’s been too hot in the desert to really ride, but I have been making some changes. Recent shock changes : lainer compression adjuster and main piston...

It’s been too hot in the desert to really ride, but I have been making some changes. 
Recent shock changes : lainer compression adjuster and main piston, shortened shock 2mm (dropped rear of bike 5mm)

Still playing with valving on the kyb cartridges, installed Enzo spring tubes yesterday. Forks feel busy now and a little too soft in top and mid stroke, will be making adjustments to valving soon. 

Overall the balance and front end feel are improved and I feel I can get the rear pretty good once I get to the track. One thing I’ve learned is what feels good in my local terrain does not translate well to Glen Helen. Like at all lol

Thanks for sharing your experience. 

1
lowmass
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190
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6/19/2024
Location
LANSING, NY, USA
7/9/2025 4:44am

sorry havent looked at this in a while

Reading the above posts reminds me of the issues I had with getting comfortable on the new KTM chassis. Trouble. 

IMO one of the biggest issues is simply the cockpit. The 2016-2022 chassis had a level seat with 103 sag. The new chassis has a stink bug seat with any reasonable sag numbers.

If I still had this bike I would seriously consider altering the subframe rather than trying to band aid the chassis to level with suspension mods/ adjustments.

I looked at this a bit before selling the bike and it did look possible. The rear of the seat will need to be lowered by about 10mm to get a cockpit similar to the 2016-22 bikes

BTW I have sense bought a new Triumph TF450 RC. Its basic layout/ cockpit etc is nearly identical to the 2016-2022 KTM chassis AND it feels very similar on the track. HOWEVER I would caution anyone thinking about these bikes. The reports are not good with all kinds of transmission/ ctutch/ etc issues in the motors. The chassis is trully great BUT many reporting issues in the motors. Mine came with wads of scotch bright pads, chuncks of O ring in the oil. There seems to be real QC issues at assemby and some metalurgy issues with shift drums wearing quickly on the 450s as well as clutch failures on the 250s

So far I only have 4 hrs on mine and its OK. However Im on the injured list so wont be able to comment further on it this season. 

AMetts
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1178
Joined
6/15/2022
Location
Lincolnton, NC, USA
7/9/2025 5:47am Edited Date/Time 7/9/2025 5:47am

Something that may be of interest to some of you guys, I was doing a bit of research before I purchased some used Husky MX Tech Raven inserts and I discovered that the new CC spring forks they are using in the XC bikes are 10mm shorter than the current and older air forks.

Im now running these in my 23 300 XC, its hard to isolate the fork length feel from the new inserts but the front end feel is substantially better and I gave up no stability on 4th gear fast rough sections. 

Screenshot 2025-07-09 083742Screenshot 2025-07-09 083819

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