Can't shake the shake! - Ducati.ms

Dodd · Jul 25th, 2009, 10:14 am

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 · Jul 25th, 2009, 10:48 am

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 · Jul 25th, 2009, 10:52 am

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 · Jul 25th, 2009, 10:55 am

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

wilmar13 · Jul 25th, 2009, 12:56 pm

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 · Jul 25th, 2009, 1:07 pm

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 · Jul 25th, 2009, 2:25 pm

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 · Jul 25th, 2009, 5:51 pm

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 · Jul 25th, 2009, 6:24 pm

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 · Jul 25th, 2009, 11:03 pm

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