[Dodd]

Little help here, now I know I'm sturring up a bee's nest and there will most likely be varied opinions, but anything would help at this point.

I've got an 08 S, 9K miles. Minor mods, air box drilled, and a set of Power 1's set at the correct pressure from the Michelin vendor. (They are race tires, I know, and I'm aware of there ups and down's on the street, but they work good for me)

Suspension is stock, except I put 8 turns into the pre-load adjusters in the forks, because it was way too soft. That worked well.

I've got a scotts damper that i put on a few weeks ago. It works great, and eliminated the head shake I was experiencing at lower speeds.

Problem- at higher speeds (100+ in a controlled environment) the head shake is still there. If the frame is upset in anyway (Anything, road imperfections, etc) it will wobble. This only happens in big sweepers, but is un-nerving as hell.

I have to turn the damper up all the way to keep it from becoming truly scary, and with it up that far, it really slows down my transistions from side to side.

Any suggestions?

 

[crashman]

My guess is you are trying to get it to feel like your ZX6. I am not an expert by any means but I think that by putting in all that preload you have pretty much eliminated any sag and the suspension has nothing to work with to take up the imperfections in the pavement and is transmitting bump forces directly to the chassis. I think you would be better served by taking out some of that preload and fiddling with the compression adjustor on the forks.
Take this with a grain of salt though as I thought the Hyper steered like a garbage truck until I dropped the front and raised the back. Good luck!

 

[wilmar13]

Drop your forks to raise the front end if you haven't already. That will help stabilize it by increasing the effective trail and you will gain some ground clearance. You can also drop the rear to do the same thing, but you may have clearance issues then.

 

[Dodd]

Great feedback. I'll take some preload out, and bring up the front- how far do you suggest?

 

[wilmar13]

I dropped my forks so that the top of the triple clamp was level with the end caps on the fork legs... it was only about 3/8" but you could probably go a bit more than that. I also raised the rear to the max so it is actually probably a little less stable than stock settings, but I prefer the sharp handling and peg clearance as I don't venture into triple digits often and like it quick for around town. Just raise the front and it should help feel more steady at high speed.

 

[Decreasing Dave]

Dodd,

Don't just twist the preload up or down without setting sag. You'll be wasting your time and your best hope would be to get lucky on set-up. Set the sag numbers so that the suspension can work in the proper range. Then you can use the compression to stiffen it a little, but don't forget the rebound.

Typically, your preload gets changed ONCE all things being the same.....until they aren't (i.e. passenger, luggage, etc....). Then you need to work the dials to get the best (for you) performance.

Dave

 

[Dodd]

Thanks fellas-
I think its time to go see someone about it- I read ton's on suspension set up and I just get more confused. I had a shop in Denver set up my race bike (Bump for Faster! Motorsports Denver, Co) and maybe I'll just take her down and have a pro set it up.

I also need to be aware that it is not a roadracer, and just deal with that- It does everything well, and that I ask it to. Its just to fun to leave the faring clad superbikes in my goofy mirrors through the twistys, all on a 90 hp air cooled naked bike.

Thanks again!

 

[AXE]

I agree with Dave, you have way too much preload up front, especially if you cranked it down from stock. Back it out some and set the sag front and rear. In my opinion, once you get the rear dialed in the front head shake will nearly be gone. If you can get the front to match, this suspension is pretty good. You can't get it perfect unless you match the spring rates, oil, valving, etc. for your weight and riding style, but you should be able to get it close. You will have to spend some cash to get it perfect.

I personally don't see a need for a dampner, but if you already have one then you may as well leave it on.

If you ain't comfortable with setting the sag, then try Boulder Motorsports. I hear they are very good.

Out!

 

[hypersonic]

Hi Dodd,

I just put Power 1's on my hyper and the front end is nervous as ever. If I hit a small bump at 90mph it wants to start oscillating. This started when I mounted the tires this week. Prior to these tires I ran the Bridgestone BT-002RS and had set my sag and the bike was very stable and handled like a dream. I am convinced that the tire size quickend the steering by raising the rear or lowering the front or both. Anyway, I am going to drop my forks in the clamps until the caps are flush w/ the top of the clamps as others have suggested. This should fix it.

Something about the tires definitely! (they should be awesome once set up)

 

[kingsnake1650]

Do you still have the hand guards on the bike? If so I would say that is your problem

 

[slowrider]

Do you still have the hand guards on the bike? If so I would say that is your problem

Is that because of the extra weight at the bar ends? Or because of air catching guards?

 

[kingsnake1650]

I think its because they catch air... I went through the same problems on my hyper. I worked the suspension and just couldnt get all the wobble dialed out and keep the low and mid speed cornering feel that I wanted. After taking the guards off most of the high speed wobble went away. Mine still seems to get a little light feeling in the front over 100mph but it doesnt wobble, and isnt much of a problem because I dont do much riding at that speed.

 

[PedroHM]

well i had mine pinned all the way to the red line in 6th yesterday at the creek, 240 ish on the dial and the only shake i get is coming out the last turn hard on the gas in 3rd whilst yanking the bars to stand it up. perfectly ok and the track is not exactly smooth and I don't have a damper.

just cranking on preload because the front end is 'soft' is not your answer dude. you've fucked up the geomertry. what you need to do is set the sag front and back and if the front is diving too much because the spring is soft then you need to resolve that issue as best as poss.

you could try winding off the rebound as that will cause slappers when the suspension can't react to the road surface when you gas it.

quite simply go back to basics and start again.

 

[ADHD]

Dodd,

Go back to the stock preload rebound and compression settings; set front and rear sag; then fiddle with rebound and compression. And take notes on what you did and whether or not you like it or not. It could just be the Michelins profile but you'll never know if don't set the sag.

 

[lelenb]

Hi Dodd,

I just put Power 1's on my hyper and the front end is nervous as ever. If I hit a small bump at 90mph it wants to start oscillating. This started when I mounted the tires this week. Prior to these tires I ran the Bridgestone BT-002RS and had set my sag and the bike was very stable and handled like a dream. I am convinced that the tire size quickend the steering by raising the rear or lowering the front or both. Anyway, I am going to drop my forks in the clamps until the caps are flush w/ the top of the clamps as others have suggested. This should fix it.

Something about the tires definitely! (they should be awesome once set up)

Just a thought but could there be a slight bind in your fork legs from remounting the tire? Did you work your forks with the front axle assembly slightly loose before you torqued everything down? Sometimes a small imperfection does not reveal itself except at speed. What about balance, could it have thrown a weight?

 

[hypersonic]

Well, I dropped my forks in the yokes to compensate for the tire size difference of the Michelin Power 1's. Now it is completely calm and stable even at high speeds as it was before the change to the Power 1's. I don't see any need for a damper unless I later jack up the rear for quicker steering at the track and better ground clearance.

It is important to first set your sag while sitting on your bike to about 1/3 of total travel. This allows the suspension to work in it's propper range for your weight. It is not intended to change ride height/geometry.

Then if it is still nervous on the front end you have to slow the steering down by changing the ride height. You can either drop the forks in the clamps (thereby raising the front) or drop the rear by adjusting the ride height adjuster if you have an "S" model. However it is likely the ride height adjuster is already at the low setting (if you haven't changed it already) so dropping the forks in the yokes till flush is your best bet.

Ducati set the ride height up for the Corsa III's not the Power 1's.
Tires vary in diameter.