Understanding Sag...

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2/13/2018 5:46 PM
Edited Date/Time: 2/13/2018 6:04 PM

2017 Husky FC 350
Motocross
Vet - C class (pretty decent in corners, chicken shit on jumps for now)
170 lbs

My understanding of suspension is this, and should be done in this order:

Spring Rate - objective number based on rider weight

Valving - subjective based on riding type & skill. Also used to fix flaws in OEM hardware.

Clickers - fine tuning to suit speed/skill of rider



Bike in stock form felt really tall in rear. Yet OEM spring is 42 and should've been perfect for my weight. In OEM form, bike came with:

6mm preload
35mm static sag
105mm rider sag

I added the Pro Circuit linkage. That dropped the rear considerably and threw off the Spring Rate. Rider sag jumped to 140mm.

Oddly enough, I was more comfortable on the bike in the turns. And thus faster. It felt lower and I could “feel” more.

I was costantly taking shit for my setup tho from friends who are way faster than me and know more about this sorta stuff.

So I got the right spring (45n) and set it to 6mm of preload.

At 6mm of preload, this was where we were:

43mm static sag
116mm rider sag

Maybe I could’ve gone a spring stiffer? Im on a weight loss mission so I’ll make it up on that end.

I got the static & rider sag down to where it’s recommended (35/108). Went riding. Back to where I started when the bike was new. Felt too tall in the corners.

Im considering raising the sag back up. Minimal preload (6mm).

This will raise the rider sag to 116 again. Still way lower than what I liked before. But also way out of whack from what is recommended. What is the downside to this? And am I chasing the wrong gremlin?

My next attempt is to increase the rebound dampening considerably so that the bike starts to pack a little once I set it in a rut. This will give me the feel Im looking for (low rear) or am I wrong?




Any and all advice welcome.

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2/13/2018 6:08 PM

IMO the sag range is a suggestion. Doesnt mean you cant ride outside of that range. For a while i rode a ‘92 kx125 on stock suspension weighing 300lbs and had zero issues. If you have a setup that you like, run it. Until you get stability issues then leave it alone.

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2/13/2018 6:26 PM

What air pressure are you using in the forks?

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2/13/2018 6:28 PM

6/35/105 is what you should be using.

Paw Paw

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2/13/2018 6:32 PM

slipdog wrote:

What air pressure are you using in the forks?

Ive done a ton of reading/searching around for some sort of Pressure Chart that would correlate with Spring Rates. For whatever reason WP never issued such a document. But from what Ive gathered:

150 lbs = 9.65 bar / 140 psi
170 lbs = 10.0 bar / 146 psi

Ive been running at 10 bar. As the day goes on, the pressure drops. I tend to get more comfortable and faster. But that could simply be because of seat time.

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Part of Speech: Noun

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Usage: Slang

2/13/2018 6:33 PM

Paw Paw 271 wrote:

6/35/105 is what you should be using.

Paw Paw

Right.

So what's the downside to what I was doing when rider sag was at 140mm?

And was I playing with sag when I should've been increasing the rebound dampening?

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Part of Speech: Noun

Definition: A loser, poser, lame-ass. One who talks the talk, but could never walk the walk.

One who talks shit and doesn't back it up, but rather ends up eating their shit in return. A fuckin 'tard.


Usage: Slang

2/13/2018 6:57 PM

Jabroni wrote:

Ive done a ton of reading/searching around for some sort of Pressure Chart that would correlate with Spring Rates. For whatever reason WP never issued such a document. But from what Ive gathered:

150 lbs = 9.65 bar / 140 psi
170 lbs = 10.0 bar / 146 psi

Ive been running at 10 bar. As the day goes on, the pressure drops. I tend to get more comfortable and faster. But that could simply be because of seat time.

The biggest problem I find most people have with air forks is they run too low of a pressure. I'm 165 and on the 350 with a 45n the bike felt balanced for me at 154psi. Below 150 the front felt low compared to the rear with 105mm of race sag. A lot of people run those forks low in pressure to try to make up for the harsh mid valve settings but it can create other issues like chassis imbalance. Just a suggestion.

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2/13/2018 7:03 PM

slipdog wrote:

What air pressure are you using in the forks?

Jabroni wrote:

Ive done a ton of reading/searching around for some sort of Pressure Chart that would correlate with Spring Rates. For whatever reason WP never issued such a document. But from what Ive gathered:

150 lbs = 9.65 bar / 140 psi
170 lbs = 10.0 bar / 146 psi

Ive been running at 10 bar. As the day goes on, the pressure drops. I tend to get more comfortable and faster. But that could simply be because of seat time.

slipdog wrote:

The biggest problem I find most people have with air forks is they run too low of a pressure. I'm 165 and on the 350 with a 45n the bike felt balanced for me at 154psi. Below 150 the front felt low compared to the rear with 105mm of race sag. A lot of people run those forks low in pressure to try to make up for the harsh mid valve settings but it can create other issues like chassis imbalance. Just a suggestion.

Ok. That is interesting feedback. Makes sense.

Ive tried the forks at the recommended 10.6 bar and in increments lower. It did not help what I am feeling in the rear.

The stiffer & taller things get, the further I feel from the ground (Im only 5' 9") and I begin to lose confidence/feel of the ground.

What do you think about my theory that if I increase rebound dampening in the shock I can get the low feel back?

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Usage: Slang

2/13/2018 7:10 PM

I would agree that can help the "Feel". I find the KTM/Husky's are very springy stock and I prefer them set quite a bit slower than the OEM recommendations. I increase rebound damping at both ends when I revalve them.

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2/13/2018 7:17 PM
Edited Date/Time: 2/13/2018 7:18 PM

slipdog wrote:

I would agree that can help the "Feel". I find the KTM/Husky's are very springy stock and I prefer them set quite a bit slower than the OEM recommendations. I increase rebound damping at both ends when I revalve them.

Ok thanks. Im gonna start adding rebound dampening. At 14 clicks at the moment. Gonna take it up to 12 and see what that does. Where do you set the rebound dampening on the shock?



Last question...

116mm riders sag with healthy (low amount) of preload (losing body weight every week and eventually sag numbers should get better)

or

108mm rider sag with a ton of preload

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Part of Speech: Noun

Definition: A loser, poser, lame-ass. One who talks the talk, but could never walk the walk.

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Usage: Slang

2/13/2018 7:38 PM

I set the rebound at 10 clicks out after I've added a little internally, but felt most planted with my stock test bike at 6-7. As far as your sag numbers go, I was getting 105 with 4mm of preload.

I can't honestly comment to specifics with your set up because that PC linkage is quite a bit different than stock and my understanding from reading is that PC recommends you go up at least two spring sizes when in stalling the linkage. I've never tried that link out but my gut as well as your numbers say you should need a stiffer spring. Between 108 and 116 I think is up to you, if you like 116 better in back to back tests then that's what you like and I'd say run it.

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2/13/2018 8:26 PM

I have a lot of hours with stock suspension on my 2017 FC250. On the forks I discovered that using the clickers was essential in order to keep them from running too low in the stroke. I run 12 out on both comp and rebound at the moment with 9.3 bar and flush with the triple clamp.
As for the shock, it like 10 out on the rebound 1 1/2 turns out on hi-speed comp and 10-12 out on low-speed comp.
As for sag, I am 160lb and like my previous huskies 98mm rider sag is awesome. At my current weight that's 32mm static sag. But any static sag between 27 and 32mm is gonna work very good with the above clicker settings.
Again, these are absolutely stock , no internal modifications.
Over the hours I tested every suggestion that was given and this is what works for me and nearly every rider who has ridden my bike from novice to true intermediate.
Peace

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2/13/2018 8:27 PM

Jabroni wrote:

2017 Husky FC 350
Motocross
Vet - C class (pretty decent in corners, chicken shit on jumps for now)
170 lbs

My understanding of suspension is this, and should be done in this order:

Spring Rate - objective number based on rider weight

Valving - subjective based on riding type & skill. Also used to fix flaws in OEM hardware.

Clickers - fine tuning to suit speed/skill of rider



Bike in stock form felt really tall in rear. Yet OEM spring is 42 and should've been perfect for my weight. In OEM form, bike came with:

6mm preload
35mm static sag
105mm rider sag

I added the Pro Circuit linkage. That dropped the rear considerably and threw off the Spring Rate. Rider sag jumped to 140mm.

Oddly enough, I was more comfortable on the bike in the turns. And thus faster. It felt lower and I could “feel” more.

I was costantly taking shit for my setup tho from friends who are way faster than me and know more about this sorta stuff.

So I got the right spring (45n) and set it to 6mm of preload.

At 6mm of preload, this was where we were:

43mm static sag
116mm rider sag

Maybe I could’ve gone a spring stiffer? Im on a weight loss mission so I’ll make it up on that end.

I got the static & rider sag down to where it’s recommended (35/108). Went riding. Back to where I started when the bike was new. Felt too tall in the corners.

Im considering raising the sag back up. Minimal preload (6mm).

This will raise the rider sag to 116 again. Still way lower than what I liked before. But also way out of whack from what is recommended. What is the downside to this? And am I chasing the wrong gremlin?

My next attempt is to increase the rebound dampening considerably so that the bike starts to pack a little once I set it in a rut. This will give me the feel Im looking for (low rear) or am I wrong?




Any and all advice welcome.

Got your DM.

So...what do you think you need help with? Are you experiencing any precise problems?

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2/13/2018 9:12 PM

The problem you have is swapping out the linkage changes spring force and damping force to now you have two variables to optimize instead of one.

6mm 35mm 105mm suggests spring rate is bang on like paw paw suggests.

Maybe slipdog will clarify, but on many shocks, the rebound works on a common circuit, so when you increase rebound damping it also increases compression damping.

I've found my fc450 a bear to get balanced, even though I suck, I can balance a bike... But I was given the wrong rate spring, plus, after 15 years of Suzuki it's wierd riding another brand that doesn't turn on a dime lol.

Slipdog also makes good points on the midvalve setting on these forks.... really thrown me through a loop.

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2/13/2018 9:13 PM
Edited Date/Time: 2/13/2018 10:12 PM

Jabroni wrote:

2017 Husky FC 350
Motocross
Vet - C class (pretty decent in corners, chicken shit on jumps for now)
170 lbs

My understanding of suspension is this, and should be done in this order:

Spring Rate - objective number based on rider weight

Valving - subjective based on riding type & skill. Also used to fix flaws in OEM hardware.

Clickers - fine tuning to suit speed/skill of rider



Bike in stock form felt really tall in rear. Yet OEM spring is 42 and should've been perfect for my weight. In OEM form, bike came with:

6mm preload
35mm static sag
105mm rider sag

I added the Pro Circuit linkage. That dropped the rear considerably and threw off the Spring Rate. Rider sag jumped to 140mm.

Oddly enough, I was more comfortable on the bike in the turns. And thus faster. It felt lower and I could “feel” more.

I was costantly taking shit for my setup tho from friends who are way faster than me and know more about this sorta stuff.

So I got the right spring (45n) and set it to 6mm of preload.

At 6mm of preload, this was where we were:

43mm static sag
116mm rider sag

Maybe I could’ve gone a spring stiffer? Im on a weight loss mission so I’ll make it up on that end.

I got the static & rider sag down to where it’s recommended (35/108). Went riding. Back to where I started when the bike was new. Felt too tall in the corners.

Im considering raising the sag back up. Minimal preload (6mm).

This will raise the rider sag to 116 again. Still way lower than what I liked before. But also way out of whack from what is recommended. What is the downside to this? And am I chasing the wrong gremlin?

My next attempt is to increase the rebound dampening considerably so that the bike starts to pack a little once I set it in a rut. This will give me the feel Im looking for (low rear) or am I wrong?




Any and all advice welcome.

DaveJ wrote:

Got your DM.

So...what do you think you need help with? Are you experiencing any precise problems?

......

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2/13/2018 9:22 PM

slipdog wrote:

I set the rebound at 10 clicks out after I've added a little internally, but felt most planted with my stock test bike at 6-7. As far as your sag numbers go, I was getting 105 with 4mm of preload.

I can't honestly comment to specifics with your set up because that PC linkage is quite a bit different than stock and my understanding from reading is that PC recommends you go up at least two spring sizes when in stalling the linkage. I've never tried that link out but my gut as well as your numbers say you should need a stiffer spring. Between 108 and 116 I think is up to you, if you like 116 better in back to back tests then that's what you like and I'd say run it.

Yes, I could have gone another spring size up for sure. But like I said, Im losing weight every week. This spring will be perfect shortly. And I'll even be able to go back to the 42 if I hit my goal of 150lbs.

Wow, you took it to 6 clicks out? I never wouldve thought to go that far. Now Im more confident at trying such.

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Part of Speech: Noun

Definition: A loser, poser, lame-ass. One who talks the talk, but could never walk the walk.

One who talks shit and doesn't back it up, but rather ends up eating their shit in return. A fuckin 'tard.


Usage: Slang

2/13/2018 9:26 PM

DaveJ wrote:

Got your DM.

So...what do you think you need help with? Are you experiencing any precise problems?

You post in the other thread spoke of bikes coming with too little rebound dampening.

Ive been quietly suspecting that was the case in my situation. After reading Slipdog's posts in this thread, Im convinced that is the issue.

I was hoping you could confirm as much. I'll be riding tomorrow and will start playing with the rebound dampening for the first time.

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Part of Speech: Noun

Definition: A loser, poser, lame-ass. One who talks the talk, but could never walk the walk.

One who talks shit and doesn't back it up, but rather ends up eating their shit in return. A fuckin 'tard.


Usage: Slang

2/13/2018 9:30 PM

Bruce372 wrote:

The problem you have is swapping out the linkage changes spring force and damping force to now you have two variables to optimize instead of one.

6mm 35mm 105mm suggests spring rate is bang on like paw paw suggests.

Maybe slipdog will clarify, but on many shocks, the rebound works on a common circuit, so when you increase rebound damping it also increases compression damping.

I've found my fc450 a bear to get balanced, even though I suck, I can balance a bike... But I was given the wrong rate spring, plus, after 15 years of Suzuki it's wierd riding another brand that doesn't turn on a dime lol.

Slipdog also makes good points on the midvalve setting on these forks.... really thrown me through a loop.

Yes and no. Im experiencing the same problems today as I did when the bike was brand new 6/35/105. Before I ever added the PC linkage.

The current preload is a lot more than 6mm. But the other two are 35/108 at the moment. Rebound dampening is at 14 clicks out.

Rebound and Compression are not on the same clicker.

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Part of Speech: Noun

Definition: A loser, poser, lame-ass. One who talks the talk, but could never walk the walk.

One who talks shit and doesn't back it up, but rather ends up eating their shit in return. A fuckin 'tard.


Usage: Slang

2/13/2018 9:47 PM

Bruce372 wrote:

The problem you have is swapping out the linkage changes spring force and damping force to now you have two variables to optimize instead of one.

6mm 35mm 105mm suggests spring rate is bang on like paw paw suggests.

Maybe slipdog will clarify, but on many shocks, the rebound works on a common circuit, so when you increase rebound damping it also increases compression damping.

I've found my fc450 a bear to get balanced, even though I suck, I can balance a bike... But I was given the wrong rate spring, plus, after 15 years of Suzuki it's wierd riding another brand that doesn't turn on a dime lol.

Slipdog also makes good points on the midvalve setting on these forks.... really thrown me through a loop.

Jabroni wrote:

Yes and no. Im experiencing the same problems today as I did when the bike was brand new 6/35/105. Before I ever added the PC linkage.

The current preload is a lot more than 6mm. But the other two are 35/108 at the moment. Rebound dampening is at 14 clicks out.

Rebound and Compression are not on the same clicker.

Not the same clicker, but a common circuit

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2/13/2018 9:48 PM

That's why race tech and others sell a check valve to replace the shock shaft nut... It isolates the two circuits.

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2/13/2018 11:12 PM

Bruce372 wrote:

That's why race tech and others sell a check valve to replace the shock shaft nut... It isolates the two circuits.

Did it ever occur to you that the main reason for a product like that is to force the shock to operate more like a traditional circuit that they have more experience with and better known settings?

WP is designing and testing suspension components years ahead of ever being put on a bike.

Aftermarket suspension companies usually are slower to understand and adopt design change. It may take them many months (or years) of testing to develop specs that are required for mail order suspension tuning. On the other hand, you can design a check valve to fit the new shock relatively fast which then allows you to apply your tuning data to the more conventional circuit.

It's all about business and securing your place as a company who can keep up with changing demand. They may market the check valve as some sort of improvement, but you must ask yourself if it is such a great improvement why wouldn't WP include it as a standard design?

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2/13/2018 11:12 PM
Edited Date/Time: 2/13/2018 11:14 PM

Bruce372 wrote:

That's why race tech and others sell a check valve to replace the shock shaft nut... It isolates the two circuits.

Aaah I see. Thanks for the clarification.

Gonna play around with the rebound Wednesday. I’ll report back.

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Usage: Slang

2/13/2018 11:24 PM

Bruce372 wrote:

That's why race tech and others sell a check valve to replace the shock shaft nut... It isolates the two circuits.

mxtech1 wrote:

Did it ever occur to you that the main reason for a product like that is to force the shock to operate more like a traditional circuit that they have more experience with and better known settings?

WP is designing and testing suspension components years ahead of ever being put on a bike.

Aftermarket suspension companies usually are slower to understand and adopt design change. It may take them many months (or years) of testing to develop specs that are required for mail order suspension tuning. On the other hand, you can design a check valve to fit the new shock relatively fast which then allows you to apply your tuning data to the more conventional circuit.

It's all about business and securing your place as a company who can keep up with changing demand. They may market the check valve as some sort of improvement, but you must ask yourself if it is such a great improvement why wouldn't WP include it as a standard design?

I agree, I only mentioned the check valve, not because I think it is needed, but to explain to jabroni about a common circuit.

Everyone had a good shock setting for a 2007 crf450, so if you copy that linkage, piston and shim stack you are halfway there.

The oems aren't stupid

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2/13/2018 11:27 PM
Edited Date/Time: 2/13/2018 11:28 PM

Bruce372 wrote:

That's why race tech and others sell a check valve to replace the shock shaft nut... It isolates the two circuits.

Jabroni wrote:

Aaah I see. Thanks for the clarification.

Gonna play around with the rebound Wednesday. I’ll report back.

Yep,

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2/13/2018 11:30 PM

I don't think you need a check valve btw. I was just using it as an example

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2/13/2018 11:35 PM

Bruce372 wrote:

That's why race tech and others sell a check valve to replace the shock shaft nut... It isolates the two circuits.

mxtech1 wrote:

Did it ever occur to you that the main reason for a product like that is to force the shock to operate more like a traditional circuit that they have more experience with and better known settings?

WP is designing and testing suspension components years ahead of ever being put on a bike.

Aftermarket suspension companies usually are slower to understand and adopt design change. It may take them many months (or years) of testing to develop specs that are required for mail order suspension tuning. On the other hand, you can design a check valve to fit the new shock relatively fast which then allows you to apply your tuning data to the more conventional circuit.

It's all about business and securing your place as a company who can keep up with changing demand. They may market the check valve as some sort of improvement, but you must ask yourself if it is such a great improvement why wouldn't WP include it as a standard design?

Would you say that the piston reservoir is mishandled in the same way?

Most would recommend the bladder kit. Yet even the Trax Shock doesn’t come with the bladder. I found that odd. One seems more familiar (bladder) and the other was maybe the newer tech (piston) yet not yet accustomed too?

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Usage: Slang

2/14/2018 4:20 AM

Jabroni, I think you may need to consider the effect your forks are having as well. Many times if the bike feels too tall in the rear, it's because your forks are too soft. Make sure your bike is balanced front to rear when your shock is set to optimum standards.

FYI, 140mm of rider sag would probably result in excess bottoming, as you are using up half your travel just to support your weight. The bike would feel wallowy in corners and likely have excessive rebound characteristics. It would be a soft, "springy" ride.
My suggestion is to go back to the 100-105mm rider sag setting and check to see if you have 35-50mm of static sag. If the bike sags by itself more than 50mm, your spring rate is too stiff. If the bike sags less than 35mm your spring rate is too soft. It sounds backward, but that's how it works.
Once that is dialed in, work on your fork so that it sags about the same when you sit centered on the bike. You may need to change springs and/or adjust air pressure to do this. (Sorry, not sure what fork your Husky comes with.) You can also adjust the fork position in the triple clamp to change the ride height characteristics slightly. Keep in mind this will affect your handling.

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Braaapin' aint easy.

2/14/2018 5:08 AM

Running too much sag puts your shock in the wrong part of the dampening stroke and will have a bad effect on the way the rear and front suspension works as they have to work together for the bike to handle correctly. I would not exceed 105 -107 on the race sag with the proper springs.

Paw Paw

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2/14/2018 12:00 PM
Edited Date/Time: 2/14/2018 12:05 PM

You where close in the beginning but are now way off.

Go back to 42nm 105mm sag. 15R 15C 2.5HSC. Fork 148-150psi, 15C, 13R. Can go to 10R if it is hard packed.

The only thing you can change if you are not happy with it, is go to 45nm and 105mm sag. Same clickers as starting point.

Set it to 105 sag, and then test 148 or 150psi and see what you like best. When you have set that, you can also try quarter turn on preload in rear to see if it gets better or worse. Dont touch clickers until you are done here.

You can when you found a good base setting as above, try the PC linkage but you need to get decent number there also. If you run PC linkage you should go up two steps in spring, so i would say 50nm for you.

But again, remove PC linkage and go back to above.

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2/14/2018 12:23 PM

aees wrote:

You where close in the beginning but are now way off.

Go back to 42nm 105mm sag. 15R 15C 2.5HSC. Fork 148-150psi, 15C, 13R. Can go to 10R if it is hard packed.

The only thing you can change if you are not happy with it, is go to 45nm and 105mm sag. Same clickers as starting point.

Set it to 105 sag, and then test 148 or 150psi and see what you like best. When you have set that, you can also try quarter turn on preload in rear to see if it gets better or worse. Dont touch clickers until you are done here.

You can when you found a good base setting as above, try the PC linkage but you need to get decent number there also. If you run PC linkage you should go up two steps in spring, so i would say 50nm for you.

But again, remove PC linkage and go back to above.

there you go jabroni- this is the best advice you are gonna get today- put it all back to stock and go from there. now you have the x trig, swapping a spring at the track is a 5 minute job.

IMO 140mm sag isnt the best idea, especially if you have lowered the rear with a linkage as well. If the bike is too tall, just get the optional lower seat. But I recon by your description you are a good height and weight for the stock bike.

If you run the bike that low in the back, front end grip will suffer and you are only 1 big bump away from a trip over the bars

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