Rear kicks on braking bumps...

DrSweden
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5/2/2012 12:56am Edited Date/Time 5/3/2012 7:38am
Tested another bike and realized my suspension needs to be tuned, and just wonder how you would set the rear high/low-speed and rebound if the standard setting makes rear kick up, kind of inducing an endo. Sag x 2, and spring is set properly.

I was thinking of going less on rebound, and softer on both high/low speed? I'm off?
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motokawi818
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5/2/2012 2:13am
Stiffen it. I used to always soften it and it just caused the suspension to fully collapse and then kick.
5/2/2012 3:03am
high speed comp is just for your big hits and deep in the travel pal - flat landers etc.

low speed comp is mainly g-outs from corners and power on periods, you can also attribute this setting to braking bumps as not much of the travel is engaged - short successive hits = short amounts of travel.

do you have separate hi and low speed rebound or just one dial?

if you have just the one rebound dial then it's sounding too fast and in addition you may have your low speed comp too hard, don't make the rebound too slow though or the shock will not return and will just get rough and feel like shit over busy/successive bumps.

if i were you i would knock a click off my low speed comp and a couple from rebound - then hit a patch repeatedly and see if its stopped, if still too kicky repeat. if it feels good go and do a big hit to engage the hi speed element of the shock and see how it feels from deep in the travel also - only you can decide.
5/2/2012 3:49am
You need faster rebound so your suspension has time to go back up between bumps. Otherwise it bottoms out and stays there and just bounces around.
1

The Shop

TY6
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5/2/2012 4:22am
DrSweden wrote:
Tested another bike and realized my suspension needs to be tuned, and just wonder how you would set the rear high/low-speed and rebound if the standard...
Tested another bike and realized my suspension needs to be tuned, and just wonder how you would set the rear high/low-speed and rebound if the standard setting makes rear kick up, kind of inducing an endo. Sag x 2, and spring is set properly.

I was thinking of going less on rebound, and softer on both high/low speed? I'm off?
Slow that rebound right down boss, and make the high speed compression stiffer if you are getting bucked. If you set it softer then the suspension progresses too far through the stroke, bottoms out and will buck you.
1
GrapeApe
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5/2/2012 4:33am
Summarizing the responses so far, you want to both speed up and slow down the low speed compression, high speed compression, and rebound. Good luck!
MCfan4life
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5/2/2012 4:41am
GrapeApe wrote:
Summarizing the responses so far, you want to both speed up and slow down the low speed compression, high speed compression, and rebound. Good luck!
Exactly why I posted my above comment Wink
5/2/2012 4:41am
Try dragging the rear break - it'll keep your tire sucked to the ground.
DrSweden
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5/2/2012 5:06am
Tnx for the input lads, talked to a friend, and he made me realize its not possible to go in the right direction without seeing it happen. But just to have something other than Stewart to talk about, it's CRF250 07, bike only has about 20h on it (fluids still fresh). This means Showa shock and both low and high speed compression. This kick happens at the same spot, every lap (that day), it was ONE braking bump, at the end of a high speed straight. Before this bump, I don't think there was enough to stack the suspension up?

Feels like going 2 clicks softer on high speed compression, or 2 clicks softer on rebound would be a good starter?

According Rughneck tips a while ago (when attacking whoops thread I made) seems I should go softer in genereal, and MXA indicates that as well (at least on their 2008 model). Maybe I should expect progress in that direction as well!
DrSweden
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5/2/2012 5:13am
GrapeApe wrote:
Summarizing the responses so far, you want to both speed up and slow down the low speed compression, high speed compression, and rebound. Good luck!
MCfan4life wrote:
Exactly why I posted my above comment Wink
Ha, because my initially open questions cant have that specified answers!
JB 19
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5/2/2012 5:19am
Sounds like its packing. That means the rebound is too "hard" or slow. It keeps going down further and further without returning until it gets really low and then unloads. Usually I tune suspension in two click increments and then fine tune one click.

Suspension setup is never ending though. The high speed comp can make the rear ride lower or higher.......which doesn't make sense, but it can. Making the rear softer can make the front feel stiffer. Speeding up the rebound can make it feel bouncy and unpredictable. Sometimes too soft can make it ride in the stiffer part of the stroke and actually make it feel stiffer. Suspension is such a black art. I wish I knew a lot more.
5/2/2012 5:22am
DrSweden wrote:
Tnx for the input lads, talked to a friend, and he made me realize its not possible to go in the right direction without seeing it...
Tnx for the input lads, talked to a friend, and he made me realize its not possible to go in the right direction without seeing it happen. But just to have something other than Stewart to talk about, it's CRF250 07, bike only has about 20h on it (fluids still fresh). This means Showa shock and both low and high speed compression. This kick happens at the same spot, every lap (that day), it was ONE braking bump, at the end of a high speed straight. Before this bump, I don't think there was enough to stack the suspension up?

Feels like going 2 clicks softer on high speed compression, or 2 clicks softer on rebound would be a good starter?

According Rughneck tips a while ago (when attacking whoops thread I made) seems I should go softer in genereal, and MXA indicates that as well (at least on their 2008 model). Maybe I should expect progress in that direction as well!
If the bump is all by itself it's a little different. Softening up the rebound can still help, but it could be your hi speed compressionthat's too soft, or the bike is unbalanced (ie not enough sag or forks are too soft, taking weight off the rear wheel)
DrSweden
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5/2/2012 6:36am
Crap, as jb19 suggest, this is a mess... Tonight I will ride another track, still sand but maybe my bike is more suited for that track? And then we have the psychology involved... Well, again kept us away from stewart for a while! Tnx again for the input, I will at least feel less fear in testing now, in contrast to previously were those screws gave me anxiety! Grinning
WhipMeister
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5/2/2012 6:47am
Try a different line? Wink Unless you video from the side in slow motion as the suspension does its thing, you are shooting in the dark. Then hand that over to a suspension tech. Eric Gorr did a nice video about the whole subject a long time ago. I have it in a long lost box of vhs tapes around here somewhere. It's likely packing, plus hard braking tends to lock up the suspension, amplifies front to back forces, etc.
lostboy819
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5/2/2012 7:07am
TripleFive wrote:
Try dragging the rear break - it'll keep your tire sucked to the ground.
x2
scooter5002
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5/2/2012 7:47am
Marc, only adjust ONE setting at a time. That way if what you changed was the wrong way to go, you can change it back. Try speeding up your rebound, so it re-cocks faster. 2 clicks max at a time. Your Hi-speed comp will fall into this range as well. Ride that same stretch over and over, and get the shock so it suits you. Then ride the rest of the track and see what you think.
Just a tip. Buy an Ohlins. Your from Sweden. Maybe you can get the "homey" discount. Lol. I got one for my 04 and the performance is just MIND-BOGGLINGLY better over the stocker. They just don't do anything wrong. Stuff will be coming up cheap now that your bikes a littler older.
The Rock
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5/2/2012 8:50am
Slipper clutch will reduce rear end kick substantially.

I raced the YZ250F Stealth Pro I had built with a slipper clutch before giving the bike to MXA to test and it was by far the best handling bike I'd ever raced. Neezer at Fox Shox's fork revalve and their shock had a lot to do with it but I fell in love with the slipper clutch.

Unfortunately dynos and slipper clutches don't get along so I gave the clutch back to Hinson before MXA tested it.
Suns_PSD
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5/2/2012 8:59am
Write down your starting point and hit the same obstacle repeatedly. Then make one change but do several clicks, about 4, at a time so you can REALLY feel it. In your case I'd first loosen the low speed compression. If that doesn't work put it back to your starting point and add rebound damping.

Soft squishy suspension is faster 99% of the time. I don't care what the bike does over jumps, braking bumps and acceleration chop are what matters.
ianhendry46
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5/2/2012 9:09am
high speed comp is just for your big hits and deep in the travel pal - flat landers etc. low speed comp is mainly g-outs from...
high speed comp is just for your big hits and deep in the travel pal - flat landers etc.

low speed comp is mainly g-outs from corners and power on periods, you can also attribute this setting to braking bumps as not much of the travel is engaged - short successive hits = short amounts of travel.

do you have separate hi and low speed rebound or just one dial?

if you have just the one rebound dial then it's sounding too fast and in addition you may have your low speed comp too hard, don't make the rebound too slow though or the shock will not return and will just get rough and feel like shit over busy/successive bumps.

if i were you i would knock a click off my low speed comp and a couple from rebound - then hit a patch repeatedly and see if its stopped, if still too kicky repeat. if it feels good go and do a big hit to engage the hi speed element of the shock and see how it feels from deep in the travel also - only you can decide.
this x2
if its just kicking but you like it everywhere else, I would just go a little slower on the rebound, like two clicks.
BAMX
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5/2/2012 10:25am Edited Date/Time 5/2/2012 3:47pm
This thread is a travesty. You would be better of having a witch doctor fix your bike than read this.

Buy Race Techs suspension Bible so that you have a clear understanding of what is going on. Read it front to back and then you can get an idea of where your issues may be.

Also, whoever said slipper clutch needs to be shot. He hasn't even touched the clickers and you are having him buy a mega buck clutch.
Jakes Dad
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5/2/2012 12:31pm Edited Date/Time 5/2/2012 12:33pm
Work on technique two things that helped my kid was dropping the heels. Or dragging the brake a little, I didn't like this as well as it slowed him too much a lot of times. In my uneducated little brain I think kicking is from deflection from shock compressing too far.
bvm111
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5/2/2012 1:27pm
DrSweden wrote:
Tnx for the input lads, talked to a friend, and he made me realize its not possible to go in the right direction without seeing it...
Tnx for the input lads, talked to a friend, and he made me realize its not possible to go in the right direction without seeing it happen. But just to have something other than Stewart to talk about, it's CRF250 07, bike only has about 20h on it (fluids still fresh). This means Showa shock and both low and high speed compression. This kick happens at the same spot, every lap (that day), it was ONE braking bump, at the end of a high speed straight. Before this bump, I don't think there was enough to stack the suspension up?

Feels like going 2 clicks softer on high speed compression, or 2 clicks softer on rebound would be a good starter?

According Rughneck tips a while ago (when attacking whoops thread I made) seems I should go softer in genereal, and MXA indicates that as well (at least on their 2008 model). Maybe I should expect progress in that direction as well!
Not trying to be a smart ass doc, but, if it is working everywhere else except that one spot.... change your line!
DrSweden
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5/2/2012 1:41pm
Marc, only adjust ONE setting at a time. That way if what you changed was the wrong way to go, you can change it back. Try...
Marc, only adjust ONE setting at a time. That way if what you changed was the wrong way to go, you can change it back. Try speeding up your rebound, so it re-cocks faster. 2 clicks max at a time. Your Hi-speed comp will fall into this range as well. Ride that same stretch over and over, and get the shock so it suits you. Then ride the rest of the track and see what you think.
Just a tip. Buy an Ohlins. Your from Sweden. Maybe you can get the "homey" discount. Lol. I got one for my 04 and the performance is just MIND-BOGGLINGLY better over the stocker. They just don't do anything wrong. Stuff will be coming up cheap now that your bikes a littler older.
I went all crazy on the clickers, went two at the time (high speed doesn't click though, WTF? I went almost a full turn on that sucker), so a full turn on the big 14 mm high speed red thingy, while four clicks on the low speed and finally two clicks on rebound.

The low speed one turns as well when turning the high speed? I assume that one is set towards the high speed position, and not the the overall turn?

The bike actually felt a bit better as I didn't get any kicks, but felt a bit mushy, like an old Cadillac with crappy shocks, on the beat up straights...

I know how to go back to the standard settings Andy. Tnx for the input buddy!

Well, I'm going to give this some more try, will probably end up on the standard setting. But at least I tried! Smile
DrSweden
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5/2/2012 1:43pm
DrSweden wrote:
Tnx for the input lads, talked to a friend, and he made me realize its not possible to go in the right direction without seeing it...
Tnx for the input lads, talked to a friend, and he made me realize its not possible to go in the right direction without seeing it happen. But just to have something other than Stewart to talk about, it's CRF250 07, bike only has about 20h on it (fluids still fresh). This means Showa shock and both low and high speed compression. This kick happens at the same spot, every lap (that day), it was ONE braking bump, at the end of a high speed straight. Before this bump, I don't think there was enough to stack the suspension up?

Feels like going 2 clicks softer on high speed compression, or 2 clicks softer on rebound would be a good starter?

According Rughneck tips a while ago (when attacking whoops thread I made) seems I should go softer in genereal, and MXA indicates that as well (at least on their 2008 model). Maybe I should expect progress in that direction as well!
bvm111 wrote:
Not trying to be a smart ass doc, but, if it is working everywhere else except that one spot.... change your line!
I felt his bike was better elsewhere as well, but this spot made it more obvious. But put Pourcel on my bike with standard settings and he would probably qualify for outdoors on it...
Katoom72
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5/2/2012 1:51pm Edited Date/Time 5/2/2012 2:05pm
Take into account that on most shocks the rebound adjustment also has an affect on compression damping.

Also suspension 101: If u fix one problem, you wil create another. It's all about balance and in what key part you want it better then in other parts. It's what you are willing to sacrifice to fix an issue. If you can manage to overcome one problem you create by fixing another problem, you found your perfect balance.
(For example: you can handle a bit over over/understear while gaining more stability on straights, don't mind the nervous rear when exiting a corner instead of kicking over bumps, etc)

On your issue, my suspension tech guide shows me ingoing damping to hard. Try to soften that up.
But it WIL affect other parts on the track, you'l have to try it out how mutch you want to reduce the kicks so you don't sacrifice to mutch on your current more comfortable parts.
The Rock
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5/2/2012 6:28pm Edited Date/Time 5/2/2012 6:30pm
BAMX wrote:
This thread is a travesty. You would be better of having a witch doctor fix your bike than read this. Buy Race Techs suspension Bible so...
This thread is a travesty. You would be better of having a witch doctor fix your bike than read this.

Buy Race Techs suspension Bible so that you have a clear understanding of what is going on. Read it front to back and then you can get an idea of where your issues may be.

Also, whoever said slipper clutch needs to be shot. He hasn't even touched the clickers and you are having him buy a mega buck clutch.
I just put a shirt with a target on so take your best shot but seriously folks.....

I only related my experience with a slipper clutch end of story. Single biggest handling improvement I've ever experienced and if I was actively racing I would add one to my ride before I touched the motor, exhaust or suspension.

It also made the YZ250F feel like it was a two stroke the way it eliminated the engine breaking....at first I thought that would be an issue but I think it actually helped my corner speed.

Question: BAMX-Have you had the opportunity to check out a slipper clutch?
scooter5002
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5/2/2012 8:04pm
Marc, only adjust ONE setting at a time. That way if what you changed was the wrong way to go, you can change it back. Try...
Marc, only adjust ONE setting at a time. That way if what you changed was the wrong way to go, you can change it back. Try speeding up your rebound, so it re-cocks faster. 2 clicks max at a time. Your Hi-speed comp will fall into this range as well. Ride that same stretch over and over, and get the shock so it suits you. Then ride the rest of the track and see what you think.
Just a tip. Buy an Ohlins. Your from Sweden. Maybe you can get the "homey" discount. Lol. I got one for my 04 and the performance is just MIND-BOGGLINGLY better over the stocker. They just don't do anything wrong. Stuff will be coming up cheap now that your bikes a littler older.
DrSweden wrote:
I went all crazy on the clickers, went two at the time (high speed doesn't click though, WTF? I went almost a full turn on that...
I went all crazy on the clickers, went two at the time (high speed doesn't click though, WTF? I went almost a full turn on that sucker), so a full turn on the big 14 mm high speed red thingy, while four clicks on the low speed and finally two clicks on rebound.

The low speed one turns as well when turning the high speed? I assume that one is set towards the high speed position, and not the the overall turn?

The bike actually felt a bit better as I didn't get any kicks, but felt a bit mushy, like an old Cadillac with crappy shocks, on the beat up straights...

I know how to go back to the standard settings Andy. Tnx for the input buddy!

Well, I'm going to give this some more try, will probably end up on the standard setting. But at least I tried! Smile
Marc, there are no "clicks" in the Hi-Speed Hex. A 1/8 turn on that hex is all you want to make at one time. You're correct in the "cornering assist" aspect of the Hi-Speed, because that also, to a slight degree, alters the sag on your bike so that stiffer on the setting holds the back end of the bike up. Creating a steeper head angle,and making the bike corner better.
Lol "a full turn on the red thingy" Man , you won't find THAT in a Racetech manual. Funny shit buddy. That's huge. Likely resulting in the mushy feeling.
The Low Speed does turn with the Hi, yes. That setting is more to do with jump take off, landings and G-outs. Lower speed shock shaft movements. I rarely touch that one, once I get my bike dialed. My Hi-Speed gets changed depending on whether I'm on a whooped out sand track or a square edged curb hard pack track. Back my clicker out to absorb some of those rim bending hits. Have every kind of terrain here in a 40 mile radius. Big sandy whoops , square edge tooth rattling hard pack and loam as well. I never run the same settings on any track. Same for my forks.
Set everything back to stock and work your way from there. One question: How old is your oil? Did your bike sit all winter and you're riding on last years oil or you serviced the shock fresh this spring?
5/2/2012 8:17pm
try to blip the throttle on impact even while braking. ;-) Set the rebound to "settle " the bike in the turns. bike tends to lowside then fork rebound needs to be faster .
bike seems to highside try slowing down the rebound.
BAMX
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5/2/2012 8:24pm
The Rock wrote:
I just put a shirt with a target on so take your best shot but seriously folks..... I only related my experience with a slipper clutch...
I just put a shirt with a target on so take your best shot but seriously folks.....

I only related my experience with a slipper clutch end of story. Single biggest handling improvement I've ever experienced and if I was actively racing I would add one to my ride before I touched the motor, exhaust or suspension.

It also made the YZ250F feel like it was a two stroke the way it eliminated the engine breaking....at first I thought that would be an issue but I think it actually helped my corner speed.

Question: BAMX-Have you had the opportunity to check out a slipper clutch?
No I have not tried a slipper clutch. I really don't ride my 4T much anymore and since RG3 did the suspension, I don't have an issue that makes me feel I need one. I am not saying that they are bad but I don't want to lay down $600 bucks for a test. Plus, some engine breaking on a overweight 4t isn't always bad. My point was that the guy hasn't touched one thing to tune the suspension and instead of figuring out what his problem is you are telling him to buy a clutch

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