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Discussion Starter #1
I was riding at a track day Monday at WSIR. I had my newly outfitted 06 10R there. (Race plastics, rearsets, grips, new GPR damper, 16T front sprocket, Qualifier 209GP's ( 190/60 rear tire ) ). I was having suspension problems the whole day. I tweaked and adjusted but never could come up with a best solution. The suspension is stock so I didn't expect much. Anyway, I couldn't dial out this weird "wobble", for lack of a better word. When going down the front and back straights, above 120mph the bike would do like a slow tank slapper but never really getting vigorous. The bars would slowly move back and forth not more than and inch, probably much less but it felt like a lot. It would only do it when I was on hard acceleration. When I would come to the end of a straight and set up for a corner it would stop and the bike would feel very planted and going through corners was a breeze. Any ideas from you suspension tuners what the issue might be? What is the cause of this slow oscilation and what can I do to prevent it in the future?
 

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Yankee Racer
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True but you could also have a to severe geometry set-up. The rear may be to high and the front to low. Also it could be the tires as I have heard many people talk about stability issues with the Dunlops and high speed wobble...
 

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zx10ragentblack said:
True but you could also have a to severe geometry set-up. The rear may be to high and the front to low. Also it could be the tires as I have heard many people talk about stability issues with the Dunlops and high speed wobble...
:+1: :+1:

Riding position too, if your bum is all the way back in the seat you can get this happen.
 

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Yankee Racer
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Also the 209 raises the rear up 3-5mm or so since it is a 190/60 profile and adjustments may have to be made. Have you lengthened the chain and what gearing are you running? Also have you lowered the front at all or raised the rear?
 

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Hi Booken. I had the exact same issue over 120mph on my 636 racebike when at/above 80% throttle. I also run the Dunlop 209GP 190/60. They are awesome tires! But due to the extremely hard carcass, they are succeptible to high-speed headshake unless the geometry is just right. This is what I learned from GP Suspension North. The 209GPs like to be nose-heavy going down the straights. Have you shimmed the rear shock yet? I don't know what GP recommends for 06 10r geometry, but my 636 is extremely on its nose even before running the 190/60 rear on a 5.5" wide rim. Correct geometry and a stiff steering damper is the only solution. Best of luck to ya! You'll love it once you're sorted out.
 

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zx10ragentblack said:
Also the 209 raises the rear up 3-5mm or so since it is a 190/60 profile and adjustments may have to be made. Have you lengthened the chain and what gearing are you running? Also have you lowered the front at all or raised the rear?
+1 and add a tooth to the rear since the 190/60 takes a little off.
 

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yep..same issue, same tire

messed with it for 5 track days this year...wasted a lot of track time trying to get it sorted out..finally got it "close" or manageable the last day the tires were gripping. And gripping is what these tires do best...my cornerspeeds went waaay up and I was able to get on the throttle sooner, but the high speed wobble ruined the cornering experience..

these tires (D209's, specifically the 190/60 rear on the zx10) are like a real bad woman that you just can't let go of: they do what you want when it's most important, but act up at the most in-opportune times..you want to keep giving her a try cuz the stuff she does well is so hard to forget, but you know that one day she is gonna set you up for a baaaad fall, so you move on...to Pirrellis for me personally.. :)
 

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or do you give her one last call???

I need tires on my track bonk and am agonizing over trying a set of 209's once again..Man they grip!! But do I really have the gemoetry setting s where they ain't gonna throw me off at 150+?

At any rate, on my '05 I ended up with (before taking them off and mounting up the pirellis):

removed the rear 3mm shim on the shock, rider and static sag as well as comp and rebound settings stayed the same

on the front I raised the forks (by lowering them in the tree) another 4 - 5 mm, added some preload (I liked the bike "soft" prior to the 209's), and added almost all rebound and compression that I could; 1 click out from full on Compression and 2 clicks out on Rebound.

changing the Geometry (height on both ends) helped to solve the head shake issue although it still felt "twitchy???" at high speeds, the stiffening of the front end helped the bike under braking keep it's load bearing as it was diving bad before the 209's and even worse with them due to my preference for the soft front end feel..Basically once I got faster and was on the brakes harder I had to fix the front end correctly (this would have had to get done regardless of the tires)

hope this helps....YMMV (I weigh 195 with gear) and run mid to fast Mid-Atlantic NESBA Intermediate pace.
 

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TheReb said:
or do you give her one last call???

I need tires on my track bonk and am agonizing over trying a set of 209's once again..Man they grip!! But do I really have the gemoetry setting s where they ain't gonna throw me off at 150+?

At any rate, on my '05 I ended up with (before taking them off and mounting up the pirellis):

removed the rear 3mm shim on the shock, rider and static sag as well as comp and rebound settings stayed the same

on the front I raised the forks (by lowering them in the tree) another 4 - 5 mm, added some preload (I liked the bike "soft" prior to the 209's), and added almost all rebound and compression that I could; 1 click out from full on Compression and 2 clicks out on Rebound.

changing the Geometry (height on both ends) helped to solve the head shake issue although it still felt "twitchy???" at high speeds, the stiffening of the front end helped the bike under braking keep it's load bearing as it was diving bad before the 209's and even worse with them due to my preference for the soft front end feel..Basically once I got faster and was on the brakes harder I had to fix the front end correctly (this would have had to get done regardless of the tires)

hope this helps....YMMV (I weigh 195 with gear) and run mid to fast Mid-Atlantic NESBA Intermediate pace.
We're same weight, same pace (faster end of NESBA intermediate). If anything, you need to raise the rear of your bike MORE. My bike is so much on it's nose I can barely tiptoe it around. Anyone shorter than 6' looks like Dani Pedrosa on it (can't get both feet on ground). You need an extremely aggressive geometry for the 209s. And bumping your idle up to 3000 rpm will seriously help with the mid-corner jitters.
 

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SuicideMachine said:
We're same weight, same pace (faster end of NESBA intermediate). If anything, you need to raise the rear of your bike MORE. My bike is so much on it's nose I can barely tiptoe it around. Anyone shorter than 6' looks like Dani Pedrosa on it (can't get both feet on ground). You need an extremely aggressive geometry for the 209s. And bumping your idle up to 3000 rpm will seriously help with the mid-corner jitters.
exactly the opposite of what 2 different suspension "specialists", and Dunlop themselves told me..where did you hear that to combat the changes to bike geometry for a TALLER rear tire that GROWS almost an inch under hard accelleration; that you would ADD to that adverse effect by RAISING the rear? IF it works, AWESOME!!, but it goes against all logic (not that my logic is faultless for sure)

curious as to how you came to that...

I do bump the idle up, although not as high as 3000 RPM, maybe 1800 or so on the track....and, just to clarify for others, I don't have mid corner "jitters" the bike is stable as heck mid-corner, it is under braking and HARD accelleration at very high speeds where the "twitchyness" is there with the 209's..
 

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Well, all I'm saying is my bike is dialed the f*ck in on 209GPs. GP Suspension set my geometry and it's actually not as aggressive as a few local racers I know who race the 636 for podium spots. Maybe we're getting into the differences between the 2 bikes?
 

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Discussion Starter #14
Thanks for the replies everyone. I am glad I am not the only one who has experienced this. It really did kind of put a damper on my track day. I just didn't feel comfortable driving into the corners as hard as I would have liked with the wobble there. And for those describing it as twitchy. It isn't twitchy, is it just a slow oscillation.

I am not married to the 209's. I figured I would try them since they were a tall profile tire. On my first track day on the bike I rode the day with the stock Qualifiers at California Speedway in Fontana, CA. I hit 175+, indicated, on the front straight and the bike was rock stable. And it still corned quite well. The tip in wasn't as good as the 209's but not bad.

Here is some stuff I have heard and come across but have not yet tried.

One racer said I need to raise the rear of the bike by adding length to my shock. He said that the swingarm angle is to small and the distance between the line parallel to the ground through the axel to the line parallel to the ground through the swing arm pivot needs to at minimum 12mm. I measured mine with the stock shock and it is 9mm with full preload. So when I put on my Ohlins I need to either shim it or get a longer bottom eyelet to get more length out of the shock to get the larger swing arm angle.

My wheel base is a bit longer since I put the 16T sprocket on with the stock chain. And as someone else said the bike handle corners quite nicely.

For those of you who have experienced this wobble, were you running race plastics or stock? I am wondering if the race plastics are causing some lifting of the from end at high speeds. When I ran at Fontana I was using the stock plastics.
 

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I had it w/ race plastics. A friend w/ a stock 636 had it w/ street plastics. He went out & bought a damper after that. :) The racer you talked to is right. By lowering the rear, you decrease your swingarm angle and run wide on corner exits. Shimming the rear will give your bike more of a swingarm angle and much more neutral handling traits. People don't understand what they're missing until they try this. I was one of them.
 

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booken said:
I was riding at a track day Monday at WSIR. I had my newly outfitted 06 10R there. (Race plastics, rearsets, grips, new GPR damper, 16T front sprocket, Qualifier 209GP's ( 190/60 rear tire ) ). I was having suspension problems the whole day. I tweaked and adjusted but never could come up with a best solution. The suspension is stock so I didn't expect much. Anyway, I couldn't dial out this weird "wobble", for lack of a better word. When going down the front and back straights, above 120mph the bike would do like a slow tank slapper but never really getting vigorous. The bars would slowly move back and forth not more than and inch, probably much less but it felt like a lot. It would only do it when I was on hard acceleration. When I would come to the end of a straight and set up for a corner it would stop and the bike would feel very planted and going through corners was a breeze. Any ideas from you suspension tuners what the issue might be? What is the cause of this slow oscilation and what can I do to prevent it in the future?

I use to have a similar problem when I was running Dunlop D207 GP's on my ZX-11. I would get a "weave" from the bike at speeds above 150mph, making it difficult to keep the bike in its "lane" at the track.

The D207 GP's were approximately 1/2" shorter in the front and 1" taller in the rear compared to the Bridgestone tires I was using. The taller rear tire helped sharpen the steering and the belt package increased grip by altering and enlarging the shape of the contact patch during cornering. Since the GP's rear tire belt package was constructed with cornering grip and drive off corners as its priority, the tire would grow significantly at high speed, thus compromising stability. What happened was when the tire grew at high speed, it reduced the rake/trail enough to cause the weave. This year, when I retired the bike from track use and put on the new "street" Qualifiers, I no longer had the weave. This is due to the rear tire not growing at high speeds and the Qualifiers being a little closer to the Bridgestone's in height when the bike's chassis and suspension was originally set up.

Lately though, tire manufacturers have been changing the belt package of their GP-type rear tires to control this growth, thus helping high speed stability.
 

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Discussion Starter #17
I was at Buttonwillow last weekend on my other bike. It just had its rear shock rebuilt so I went to the suspension tuner who was there to get that adjusted and asked about the 10R. He said to either drop the rear ride height or raise the front of the bike by dropping the forks in the triple trees. Since I will be changing (upgrading) the suspension on the bike really soon I think what I will eventually do is not use the 209GP tire. The stock setup on the bike was rock solid at my first track day so I am going to get that geometry back and run with similar geometry to stock.

For those of you who said to get the rear ride height way up there the tuner said that would make the condition worse. When you get to the point where you are doing the slow "figure 8" oscilation at high speed the bike is actually trying to tuck the front wheel so you are actually driving the front wheel into the ground. A stiffer front end may help but the geometry of the bike would still be off.

Seems the 06 10R has a peculiar geometry. You can't get the front and rear too far different in ride height from each other.

And on a related note, you can't push the forks up into the triple tree too far because the bike is so low you start dragging fairing all over the place. So the bottom line is if you raise the rear be prepared raise the front as well. And don't lower the bike or you start dragging parts.
 

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Wow. Good investigation Booken. Sounds like the 10 is really sensitive to geometry - more so than the 636. Are you just gonna run Michellins then?
 

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Yes the 10r is like NO OTHER when it comes to sensitivity and geo setup.

I tried the 'chopper' setup that TheReb mentions and it certainly didn't work for my 04 with pirelli DC's on it so over the last 1.5yrs its been a constant project geometry wise but now its to my liking after much trial & error.

BD
 

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Discussion Starter #20
SuicideMachine said:
Wow. Good investigation Booken. Sounds like the 10 is really sensitive to geometry - more so than the 636. Are you just gonna run Michellins then?
Either Michellins or Bridgestone. I am running the new BT002's on my other bike and I love them. So those maybe the tire I use. Which ever tire I can get for a better price will the first one I try.
 
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