I'm the new owner of a '01 M900Sie and have been riding it about a month (mostly commuting).  The bike has about 15K miles on it, but was extremely clean and well maintained.  I've noticed a "roaring" noise (although that is overstating it) coming from the front wheel somewhere that changes intensity with speed (not engine RPM) and doesn't change with braking applied.  It is loud enough to be kind of annoying at speed.  When coasting to a stop (engine idling, clutch pulled in) I can make it out, but it's not very loud.  No squeaks or noticeable roughness in the bars.  The only thing I can think of is front wheel bearings.  What is the best way to determine if it's the bearings and if that's the problem, is there a way to determine the bearing part numbers without removing the wheel so I can get the parts ordered?  Suggested source for the bearings?

First off I would raise the front end and just check the rubber. My bikes front tire is cupped right now and the increased road noise could
be as you describe. It had me confused at first but then i ran my hand over the front tire and realized
that the cupped tire was creating more road noise than usual.

That's a good thing to check first.

If the tire seems OK, remove the calipers and spin the front wheel.
See if you hear any 'rumbling'.

The bearings should be engraved with some numbers on the edge of the outer race.

The bike was bought from the local dealer and had a tune-up and brand new tires (Michelin Pilot Road) front and rear.  It has a center stand, so I bet I can prop it up under the block and get the front tire off the ground to do a wheel spin test (less caliper).  Are the bearings visible without removing the wheel?  Any trick to replacing them?  I found a nice guide to removing the front wheel on this site, so I know I can get that far.

There should be a small notch or cutout in the spacer that's between the wheel bearings.

With a small punch in the notch, you can hammer one bearing out a little ways, that'll release the spacer enough that you can then get to the inner race with a longer punch and get the bearings out.

If the tires are new and it is not an issue of tire cupping or odd wear, then I would pull the wheel off and simply inspect the bearings by rotating them with my fingers. If there is any binding or roughness, I'd replace them.

Quote from: sejman on September 24, 2008, 10:50:19 AM
Are the bearings visible without removing the wheel?  Any trick to replacing them? 

They are not visable enough to get any part numbers, but I believe the front bearings to be the same for the majority of Ducati wheels for a 25mm axle....

SKF #6005-2RS C3 with dimensions of 25mm ID x 47mm OD x 12mm width

Quote from: Speeddog on September 24, 2008, 10:55:47 AM
There should be a small notch or cutout in the spacer that's between the wheel bearings.

With a small punch placed in the notch, you can hammer one bearing out a little ways, that'll release the spacer enough that you can then get to the inner race with a longer punch and get the bearings out.

Sometimes not as easy as it sounds. With the newer style spacer, you can only get to one bearing with this method and you must remove that one first. Sometimes it is also difficult to rotate the spacer to get to different segments of the inner race since it needs to be knocked out fairly straight and true to avoid potentially disfiguring the soft aluminum of the hub. Here is a picture of the newer design spacer with ribbing. Note only one access slot...



I've change out three of four sets of bearings on these newer wheels and one was an absolute bear to get the bearing to budge. I evenutally had to use heat and modified a screwdriver tip to allow better surface area contact on the inner bearing. Here's a diagram a came up with a year or so ago...



Ideally, you need a blind-hole bearing puller, but.....where there's a will....there's a way.   

Definitely get the front wheel off the ground and spin it with your ear close to it before you start taking things apart.  You can call a dealership and ask them for the part number or go here: http://www.ducati.com/bikes/catalogs.jhtml;jsessionid=S5QX4PGHAK2AMCRNCB2SFFAKFUIHUIV4?MY=2001

Maybe you just need to grease/lube your axle.  If you do take your tire off check the axle to see if it has  grease/lube on it.  If it doesn't then that might be the culprit.  Good luck.

Quote from: uclabiker06 on September 25, 2008, 04:45:04 PM
Maybe you just need to grease/lube your axle.  If you do take your tire off check the axle to see if it has  grease/lube on it.  If it doesn't then that might be the culprit. 

Ummmm......the axle AND the inner bearings remain stationary once the axle is torqued. The only real reason to lubricate the axle is to make it easier to pull back out through the wheel.

Yes - It's clear (to me) that the sealed ball bearing is actually doing the work.  Any grease on the actual stationary axle is only for ease of removal/replacement.

So I did do a quick test by putting the bike on its center stand, getting the front tire off the ground and giving it a good spin and inspection.  Without removing the calipers, its tough to hear anything else, but there certainly is no play in the bearings or noticeable roughness.  I may see if I can get the pads to retract enough to do a better test, but I should probably just remove the calipers next - good experience anyway.

Back on the bearings themselves - seems that there is come controversy over the -C3 suffix when Googling the part number.  This is apparently some kind of grade that relates to axial "play".  Anyone know if this suffix is specified by Ducati.  Many of the sites that offer this bearing (or a cross to it) don't specify the suffix at all.

if it really is related to bearings and you need new ones, this is who i used recently for my 96 supersport that has even older marchesinis on it:  http://purvisindustries.com/index.html

they were able to find SKF bearings (italy/france), thus saving me from having to use shoddy chinese bearings.  little more pricey but i liked the peace of mind.  the bearings will indeed have a laser-etched part number, and that's basically all you need to order new ones.  i would double check the dimensions with a caliper (ID, OD depth), though, if you're ordering on the phone so that you can verify you're getting the right bearings.

and a big +1 to applying heat all around the bearing beforehand with a hairdryer (not directly ON the bearing, though).  that, combined with a slide hammer that i borrowed from richd (superduke), and they came right out.  and freezing the new bearings for a bit, combined with heating the wheel beforehand, they went in easily.