Ducati Monster Forum

Moto Board => Tech => Topic started by: mattyg on September 12, 2009, 08:12:26 PM

Title: Steering weave at low speeds. . .
Post by: mattyg on September 12, 2009, 08:12:26 PM
Just got my first Monster on Thursday. It's a 1996 M900 - Sweet looking bike (I'll post pics one of these days). The previous owner outfitted it pretty well w/ lots of goodies and it's very clean.

The one issue I have is that the bike has a very slight weave at lower speeds. The bike gently sways back and forth ~ it's a little disconcerting although it doesn't make it unrideable. Does anyone know what might be causing this? Other than that the bike seems cherry.

:-*
Title: Re: Steering weave/wobble at low speeds. . .
Post by: Ducatl on September 12, 2009, 08:29:53 PM
Wobble as in something feels loose? Can you describe it a bit more or where it feels like it's coming from? Is the chain/rear axle properly aligned?
Title: Re: Steering weave at low speeds. . .
Post by: mattyg on September 12, 2009, 08:32:50 PM
I edited my post - it's best described as a "weave". Nothing feels loose. The bike gently sways back and forth slowly. It's not a violent shaking.
Title: Re: Steering weave at low speeds. . .
Post by: ducpainter on September 13, 2009, 12:41:28 PM
Check the steering head bearings for 'notchiness'.

It could also be a tire issue. How old are they?
Title: Re: Steering weave at low speeds. . .
Post by: Bones on September 13, 2009, 04:40:04 PM
+1 on tires. may be old. also double-check the pressure.
Title: Re: Steering weave at low speeds. . .
Post by: Norm on September 14, 2009, 05:57:49 AM
Got a steering damper? If so, back it off.
Title: Re: Steering weave at low speeds. . .
Post by: mattyg on September 14, 2009, 06:08:55 AM
The tires are pretty new & I've tried different settings on the steering damper and it doesn't seem to affect it.
Title: Re: Steering weave at low speeds. . .
Post by: hypurone on September 14, 2009, 06:16:25 AM
I would disconnect the damper completely to verify it is not binding/frozen...
Title: Re: Steering weave at low speeds. . .
Post by: speedevil on September 15, 2009, 04:22:40 AM
99 times out of 100, a low-speed oscillation (weave) is caused by the stem bearings being too tight.  If they are worn, perhaps the PO lubed them and overtightened them when reassembling.

Somehow (using a rear stand and a jack is a safe way) get the front wheel off the ground so that you can check for any "notchy" feel in the steering stem bearings.  Unless you're an expert it will be very difficult to tell if the bearings are too tight.  The fork pull test is the proper way to check for the correct preload on the stem bearings, the procedure is in the shop manual.

My money's on the bearings being too tight - a small problem that's easily fixed.