Resprung bike, finally corners great but handles horribly in the chop

mtbkris2
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Bought a 22 yz450 after a few years off. Knew after the first ride it needed a respring. I resprung it (front and rear) using RTs spring calculator. 
 

Rode it for the first time today at Pala with the new springs and spent a while playing with clickers until corners felt good but one problem I couldn’t quite figure out was the horrible front end feel in the chop. I didn’t know if it’s compression or rebound that needed adjustment and what I did try didn’t help.
 

Whenever I hit the chop I would immediately get horrible arm pump and it felt like I was holding on for dear life no matter how much I was squeezing with my legs. It constantly felt like the bike was coming off the ground and just overall unstable. 

Im 5’8”, 155lb, running 104mm sag, 4mm fork height, and ended up at 12 out on fork compression 7 out on fork rebound, shock currently at stock clicker position. 

 

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j368
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2/18/2024 4:36pm

Did it seem like you were getting headshake?Might want to try going stiffer on the compression a couple clicks and test that. That puts it higher in the stroke both front & rear which is more plush than if you’re riding low in the stroke, that’s more harsh. If you don’t feel like the bike is planted on the ground, the rebound may be too slow and not getting the tires back to the ground fast enough. Try 2 clicks at a time and ride a couple laps and see if you feel improvement. Once you know you’re going in the right direction fine tune 1 click at a time. If you feel like you’re getting headshake, check the torque on the steering stem nut. A lot of people tighten it more than spec to reduce any headshake. Hope that all makes sense. 

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MxAddic
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2/18/2024 6:06pm

Did you go down in spring?

mtbkris2
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2/18/2024 6:40pm
j368 wrote:
Did it seem like you were getting headshake?Might want to try going stiffer on the compression a couple clicks and test that. That puts it higher...

Did it seem like you were getting headshake?Might want to try going stiffer on the compression a couple clicks and test that. That puts it higher in the stroke both front & rear which is more plush than if you’re riding low in the stroke, that’s more harsh. If you don’t feel like the bike is planted on the ground, the rebound may be too slow and not getting the tires back to the ground fast enough. Try 2 clicks at a time and ride a couple laps and see if you feel improvement. Once you know you’re going in the right direction fine tune 1 click at a time. If you feel like you’re getting headshake, check the torque on the steering stem nut. A lot of people tighten it more than spec to reduce any headshake. Hope that all makes sense. 

Your theory on the fork compression makes sense, I think I’ll try going a little stiffer next time out. It didn’t quite get to head shake but it did feel a little nervous so I do intend on tightening that nut a little bit before next ride. 
 

Sometimes it kinda felt like my front wheel was pinging off the chop and other times I could feel my rear kicking up.
 

This suspension stuff feels like wizardry 

1
Nairb#70
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2/18/2024 7:09pm

Add a tooth on the rear.Laughing

The Shop

2/18/2024 7:12pm
Nairb#70 wrote:
Add a tooth on the rear.

Add a tooth on the rear.Laughing

Jody is that you?

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Melicar
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2/18/2024 8:25pm

Did you use Race Tech Springs? (I assume so)  Did you install all the fork spring spacers?  They tend to recommend light in the front and their fork springs are 6-8mm shorter than OEM. 

1
wrc777
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Fantasy
2/19/2024 5:12am

Race tech is usually much lighter on front fork springs than any OEM. I assume Racetech assumes very different fork valving to compensate. How much did you change from OEM? At your weight I would think 1 rate lower front and rear would have been about right.

 

What is probably happening is the front is too soft and it is riding too low in the stroke and packing. I bet it does feel great cornering as that year of Yamaha has less steering/more stability.

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mtbkris2
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2/19/2024 9:27am

I’m really hoping it’s not riding too low in the corners lol that was the best I felt cornering even before I took several years off. 
 

IIRC I’m at 5.4 in the rear and .46 in the front and yes RT springs. Yes preload was properly set using the provided spacers

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avidchimp
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2/19/2024 10:52am
mtbkris2 wrote:
Bought a 22 yz450 after a few years off. Knew after the first ride it needed a respring. I resprung it (front and rear) using RTs...

Bought a 22 yz450 after a few years off. Knew after the first ride it needed a respring. I resprung it (front and rear) using RTs spring calculator. 
 

Rode it for the first time today at Pala with the new springs and spent a while playing with clickers until corners felt good but one problem I couldn’t quite figure out was the horrible front end feel in the chop. I didn’t know if it’s compression or rebound that needed adjustment and what I did try didn’t help.
 

Whenever I hit the chop I would immediately get horrible arm pump and it felt like I was holding on for dear life no matter how much I was squeezing with my legs. It constantly felt like the bike was coming off the ground and just overall unstable. 

Im 5’8”, 155lb, running 104mm sag, 4mm fork height, and ended up at 12 out on fork compression 7 out on fork rebound, shock currently at stock clicker position. 

 

I second speeding up the rebound on the forks. 7 out is a little (lot) slow and may be causing the forks to pack in the choppy stuff.

1
2/19/2024 10:18pm

I’ve got a ‘21 and had some front end issues. I sent it to enzo and they went a half rate up in the front (+1 rate in the left tube only) and the bike was much more balanced. You could try putting the stock spring back in the left side and see how she feels. 

MxAddic
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2/20/2024 3:55am

RT runs lighter rates than most but makes it up with valving.  You’re too low in the stroke. Either your packing or the spring is allowing it to drop.

Organicgun
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2/20/2024 7:29am

The rebound is too stiff.  7 out with stock valving is pretty slow especially if you have softer springs so it’s packing and holding the front down. Unless you’re riding deep sand. I would suggest 10-12 out area as a starting point. 

1
mtbkris2
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2/20/2024 10:15am

Thanks for the input guys, I’ll prob just reset to stock clicker positions and then start tinkering again from there. 
 

I think you all are right about compression being too soft. It felt way too stiff during my first few laps with the setup so I softened compression a few clicks when I prob shoulda waited for the new setup and the track to break in. Then I remember the chatter felt like it was kicking my front end up, so I assumed it was too fast on the rebound and slowed it down. I could see how this would force me lower in the stroke and make it feel harsher and maybe even cause it to kick up if it bottomed out. 
 

I guess I made some rookie mistakes. I’m going to give it another shot at my next ride after doing some more reading. The fact I even touched my clickers is progress in my book. I used to just run stock settings no matter what and it used to work for me when I was younger and more nimble. Not so much anymore lol

2
2/20/2024 5:56pm

Flip - flop your clickers settings (C7 / R12) and see how it works. 

1
cwtoyota
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2/21/2024 10:23am
mtbkris2 wrote:
Thanks for the input guys, I’ll prob just reset to stock clicker positions and then start tinkering again from there.    I think you all are...

Thanks for the input guys, I’ll prob just reset to stock clicker positions and then start tinkering again from there. 
 

I think you all are right about compression being too soft. It felt way too stiff during my first few laps with the setup so I softened compression a few clicks when I prob shoulda waited for the new setup and the track to break in. Then I remember the chatter felt like it was kicking my front end up, so I assumed it was too fast on the rebound and slowed it down. I could see how this would force me lower in the stroke and make it feel harsher and maybe even cause it to kick up if it bottomed out. 
 

I guess I made some rookie mistakes. I’m going to give it another shot at my next ride after doing some more reading. The fact I even touched my clickers is progress in my book. I used to just run stock settings no matter what and it used to work for me when I was younger and more nimble. Not so much anymore lol

I was thinking along the same line as the guys above saying to back out the rebound clicker.

As a general rule when I move up a spring rate I click in at least two clicks of rebound and when I go down a spring rate I back off at least two clicks.

This method has worked well for me when I'm searching for clicker settings on a fork:

Find yourself a flat turn or a wide very low banked corner and back the rebound out two clicks, ride the corner twice and see how it feels.  Keep repeating this process (two clicks, two test corners) until the bike feels like it's going wide at the exit of the corner.
That helps you find the fastest acceptable rebound (for cornering). 
Focus on corner exit as you roll the throttle on.  Hopefully you can find a corner without any ruts.

Starting from that point, do the same process going in (slower) on the rebound adjuster two clicks at a time.
That helps you find the slowest acceptable rebound (for cornering).

Set your rebound clicker to the middle of that range and go ride the choppy stuff.  
Play with both clickers, but stay in that range of rebound so you know your cornering won't suffer too much.

If you change your sag, fork height or compression settings a substantial amount, you may have to repeat that rebound testing process to establish a new range.

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