Ducati Monster Forum

Moto Board => Tech => Topic started by: Howley on June 11, 2011, 07:17:15 PM

Title: Skittish under heavy braking.
Post by: Howley on June 11, 2011, 07:17:15 PM
I changed the forks on my '94 900 a while back from the stocks to showa adjustables of the same era.
Since then, I've noticed the front end seems really skittish under heavy braking, sometimes, if the road is rough, to the point of feeling like I'll lose the front.
Any suggestion as to what needs adjusting?
Title: Re: Skittish under heavy braking.
Post by: jerryz on June 11, 2011, 07:22:26 PM
If the forks came off an S4 than this is a problem as they are crap read this thread  www.ducatimonsterforum.org/index.php?topic=49759.0 (//http://)


If they came off an SBK they can be sorted I have similar problems with an S4

but my M750 and 750ss are fine with standard forks non  adjustable
Title: Re: Skittish under heavy braking.
Post by: ducpainter on June 11, 2011, 07:27:23 PM
Did you change tires?
Title: Re: Skittish under heavy braking.
Post by: Howley on June 11, 2011, 08:09:35 PM
This is them:
(http://i19.photobucket.com/albums/b157/howleylongboards/b93ee559.jpg)
DP I didnt put new tires on. Forks were the only change, didn't lower the front or anything.
Title: Re: Skittish under heavy braking.
Post by: ducpainter on June 11, 2011, 08:20:35 PM
Quote from: Howley on June 11, 2011, 08:09:35 PM
This is them:
(http://i19.photobucket.com/albums/b157/howleylongboards/b93ee559.jpg)
DP I didnt put new tires on. Forks were the only change, didn't lower the front or anything.
Just because you now have adjustment doesn't necessarily mean the settings...spring rates etc... are right.

How is sag?
Title: Re: Skittish under heavy braking.
Post by: Howley on June 11, 2011, 08:52:07 PM
Sag is spot on.
Title: Re: Skittish under heavy braking.
Post by: ducpainter on June 11, 2011, 08:54:16 PM
Quote from: Howley on June 11, 2011, 08:52:07 PM
Sag is spot on.
Add some compression ?
Title: Re: Skittish under heavy braking.
Post by: Howley on June 11, 2011, 10:46:49 PM
How much will make a difference? One click? Three clicks? I don't have any experience with adjustable suspension.
Title: Re: Skittish under heavy braking.
Post by: Raux on June 12, 2011, 02:36:39 AM
what about tire pressures?
Title: Re: Skittish under heavy braking.
Post by: Ddan on June 12, 2011, 02:51:24 AM
Quote from: Howley on June 11, 2011, 10:46:49 PM
How much will make a difference? One click? Three clicks? I don't have any experience with adjustable suspension.

Base settings ( I think) are 3-4 clicks out from fully seated.  I'd set both compression and rebound there and then make adjustments to one or the other 2-3 clicks at a time until it felt right
Title: Re: Skittish under heavy braking.
Post by: Howley on June 12, 2011, 03:18:29 AM
Raux, tire pressures were recently checked and ok. Dan, thanks, I set them to their base setting when I put them on (but I forget what that was).
Would you say I need to go in or out on compression?
Title: Re: Skittish under heavy braking.
Post by: Ddan on June 12, 2011, 04:07:51 AM
Pretty hard to say from here.  I'd take two clicks out of rebound first and see if that made any change.
Title: Re: Skittish under heavy braking.
Post by: ducpainter on June 12, 2011, 04:32:52 AM
I don't think rebound adjustments will help if the front is skittish while loaded.

How much are the forks compressing under heavy braking? Are you bottoming?
Title: Re: Skittish under heavy braking.
Post by: Cloner on June 12, 2011, 05:24:58 AM
What do you mean by "skittish"?  Is it wallowing?  Is it pushing?  Is it just plain old rough?

DP is right in saying that simply changing the forks won't help you much.  To make matters worse, the adjustability of stock forks is virtually useless.

Try this.....adjusting the compression damping ONLY (at the bottom of the fork leg) by turning both of them all the way clockwise.  Ride a little, then adjust them both all the way counterclockwise and ride some more.  Did you feel any difference?  I thought not.

The answer is to spring the bike (forks and shocks) to your weight and riding style, then to get the damping to do what you want, again for your weight and riding style.  RaceTech gold valves, or similar products made by others will work wonders.   Oh.....and they'll make it where you CAN feel a difference when you make adjustments!

Sorry for the bad news.  No cheap quick fixes out there that I'm aware of.  You either spend the money to set it up right, or spend several thousands of dollars to buy top shelf bits and order them with the corret springs and damping rates.
Title: Re: Skittish under heavy braking.
Post by: jerryz on June 12, 2011, 10:56:07 AM
before you waste any money on stock Ducati showa adustable forks read the article by Torbjon in the other thread  as I have wasted a fortune on my S4 and the forks are still suspect .even revalves , springs may not help as the standard adjustable showas have a design error .
Title: Re: Skittish under heavy braking.
Post by: Howley on June 12, 2011, 03:12:26 PM
Well that won't be a problem because I have no money to spend. If I can't help the situation with adjustments I'll just have to deal with it for now.
Title: Re: Skittish under heavy braking.
Post by: bikepilot on June 13, 2011, 02:53:49 PM
Describe the skittish stuff a bit more and maybe we can help you move in the right direction with free or nearly-free tweaks.  Did you put fresh oil in the new forks when you put them on?  If so, what oil level did you go with?
Title: Re: Skittish under heavy braking.
Post by: Howley on June 13, 2011, 09:46:29 PM
The forks were new old stock so I didn't touch the oil.
By skittish I mean loose, almost like it's intermittently locking up, and like it has very little traction.
Title: Re: Skittish under heavy braking.
Post by: ducpainter on June 14, 2011, 03:35:57 AM
Quote from: Howley on June 13, 2011, 09:46:29 PM
The forks were new old stock so I didn't touch the oil.
By skittish I mean loose, almost like it's intermittently locking up, and like it has very little traction.
Did you verify they had oil from the factory?
Title: Re: Skittish under heavy braking.
Post by: bikepilot on June 14, 2011, 10:11:37 AM
^

And that steering head bearings are properly adjusted and in good shape?  Forks really shouldn't make a huge diff on traction like that. Your problem really doesn't sound like the typical sub-par monster damping.  That's more like something is way, way out of whack.  No oil, way too much oil, compression settings maxed out one way or another, loose steering head bearings, really shot wheel bearings etc.

Title: Re: Skittish under heavy braking.
Post by: Howley on June 14, 2011, 03:27:53 PM
I didn't check they had oil, just kinda assumed. Head bearings are ok (not loose), forks aren't bottoming out (according to the zip tie on the slider), compression settings are on the baseline (few clicks out, can't remember exactly), and wheel bearings seem good, not loose or anything.