Front wheel bearing service!!!!

[JWilliam]

I heard a rumour about this a few months ago and tried it out this weekend. You can remove the dust seal for the front wheel bearing to clean and repack them with grease. Owing to the awkward removal procedure for worn front bearings this should fill the average Paso owner with joy!



Using a small flat blade screwdriver, ease this in from the centre of the seal and flip out the dust seal. When finished use a rubber mallet to flatten the seal because it will probably distort its shape and push back in by hand. (Apologies for the non-standard brake disc)

[enzo906]

Replacing the bearings is one of the easiest jobs to do on a paso.
Chock the frame remove the wheel
Use a old scredriver or if you have one a drift and knock the te old ones out.
Tap the new ones in using a socket so as to only contact the outside of the bearing
that's it
I did it recently as the left bearings always need replacing due to the poor seal.

If you remove the seal and repack you may be hiding the fact that the bearing is past it's best.

[Desmo_Demon]

Replacing the bearings is one of the easiest jobs to do on a paso.

The front bearings of the 16" wheels are not easy to remove because of the step-down spacer required to decrease the bearing ID of 20mm to match the 17mm OD of the front axle. I had to have a buddy of mine make a stepped drift to press out the first bearing. Here is a diagram I made to show the stepped spacer that is in the hub of the front wheel...



The rear wheel just has a conventional spacer, so changing the rear bearings are easy. Here is a picture of the actual bearings and spacer that I took out of my Paso 750...

[JWilliam]

Replacing the bearings is one of the easiest jobs to do on a paso.

No it isn't.

[jomo]

It has been a few years now, but from memory, I heated the rim slightly. I hope I am not thinking of another bike. Terribly sorry if I am wrong I sometimes help friends with their bikes, drink too much, play too hard, and after all that....the memory can drift.

I'll have to do a bearing check now!!!! Well not right now!

[Laddie907]

the rubber seal bearings are commonly known as RS or 2RS bearings (RS for single shield and 2RS for double). The 2RS deep groove ball bearings are common in bike wheels and RS type in automotive gearboxes.

The amount of lube [base grease] is controlled so it doesn't piss out during operation.
Also the type of grease used to fill them is lube-oil stable (usually an EP grease) so the lubricant oil doesn't weep out from the grease base.

I work in the conveyor industry; we don't commonly use RS type bearings because the roller RPM is too high and the contact seal has high drag. The rubber contact type seals burn out and become ineffective after a short time...but this is thousands of hours doing 24/7 operation.
The seal drag is not a problem on a bike wheel because the drag is minimal compared to the power and the hours for seal life very low..comparatively...

Picking the seal out isn't a great idea; you need to ensure the lip contacts perfectly when you re-seat it. Otherwise it will not really seal well. This will mainly be a problem in areas with very fine dust or high moisture (riding in the wet).

Most greases have a "life" of about 7 to 10 years...then the performance drops off. This doesn't mean it doesn't work any more - just not as well as new lube. A bike wheel is not a very demanding application so the life can be very high. The main cause of problems for bike wheel bearing failure is contamination and corrosion; very rarely over-loading.

to re-grease or not to re-grease that is the question....

If you're going to replace the grease you need to get the old stuff out. Why? Well, if the old grease is OK why change it in the first place? No use leaving the old stuff in if it is contaminated or crappy.

No easy answer to this one; re-greasing is OK...so long as you don't push contaminants in.
Excess grease will pump out in operation / rotation.
In reality, if the lubricant had failed, discoloured or needed replacing the bearing may be on the way out...if the grease is brown I'd replace the bearing - it is probably fretting corrosion - the brown is tiny metal particles that have rusted.

Bearings often suffer internal corrosion from galvanic current from dissimilar metals...like a magnesium rim and a steel shaft - the bearing is the bunny in the middle that cops the current (albeit very low).

The problem with these tiny bearings is you can't really inspect the bearing for serviceability until it's stuffed. you certainly can't inspect the bearing while it's in the rim because the outer race is pre-loaded with pressure from the rim - so any clearance is already taken up. [This is why the bearing is so hard to push out, by the way].

Because the wheel is a large diameter compared to the spindle the bearing can be quite bad but still rotate because of the leverage; you can find that what was easy to spin with the wheel won't turn in your fingers.

Rotate the bearing with your finger tip, try to feel for any "notchiness" or tight spots. If any irregularity is present I'd advise to change it (them) and be done with it. The bearings are comparitively cheap; compared to a road-side stop and associated crapping around.

I'd be inclined to replace the bearing if at all suspected of being failing - just to be sure, but if it ain't broke - don't fix it.

If you need to replace the bearing make or use a proper puller.
These are magnesium rims - I'm sure i don't need to tell you they are easily damaged and #$%^&*ing expensive.
Yes, it will be a pain in the ass and expensive for the DIY handyman.
Using a drift is OK only if you push the bearing out square to the axis; a screwdriver is not recommended.

[JWilliam]

I admit that a grease repack for a bearing is far from ideal, but when we look at the quirky design of the front wheel spacer I dont think I can be blamed for wanting to squeeze a few more miles from those bearings.

[ducapaso]

I admit that a grease repack for a bearing is far from ideal, but when we look at the quirky design of the front wheel spacer I dont think I can be blamed for wanting to squeeze a few more miles from those bearings.

My personal experience says:
DO NOT RE-GREASE!!!!
If the old grease is gone, the bearing is going...
If You put newer grease inside, you'll surely put contaminants in and risk to damage the rubber seal!
So...

[enzo906]

I stand by my comment that it is easy to do, no special tools were used. I don't use a pressure washer so my spacer and bearings still looked like new after 50,000kms. I replaced them as the left is not protected from the elements by the speedo drive and was showing signs of getting tight.
The bearings (if originals etc) are a size for size fit. Not interference so they only need to be tapped out with a drift or screw driver. If there is oxidation of the rim and rust on the bearing and spacer then you can use some heat but I wouldn't use much as the alloy of the wheel will expand with little heat, thus releasing the bearing.

To replace was simple as well, so I don't understand what the issue is? You can hammer away at the old ones to remove them as their trash anyway, you could probably knock it out using a socket!. The new ones tap in with a nylon mallet ( a piece of wood on the outer rim only will do in a pinch). I used a pin punch to ensure they were seated correctly. Granted there is a spacer involved but this was way easier than some of the dirt bikes I have owned. Either way hard or easy, regreasing went out with the old ball bearing cup and cone steering heads on Ducati singles.

[Desmo_Demon]

I stand by my comment that it is easy to do, no special tools were used.........so they only need to be tapped out with a drift or screw driver.

You have me really curious, now....

How did you remove the bearings from the front wheel? On my Paso front wheels, the hub spacer fits inside of the bearings to drop the ID from 20mm down to 17mm. With the shoulder of the hub spacer fitting into the inner race of the bearings, there is absolutely no way that you can use a screwdriver or ordinary drift/punch on the edge of the bearing to drive it out, and not even a blind bearing puller can be used, as the edges of the bearings are not exposed. I guess you can try to catch the 1.5mm lip of the hub spacer, but there is a huge risk of flaring the spacer, especially if heat is not used on the hub. If you do flare the edge of the spacer, you'll need to file and smooth the ID of the spacer before the axle will slide back through it.

The stock bearings are SKF 63004-2RS1 with measurements of 20mm x 42mm x 16mm. Obviously, a spacer is required to step the ID down from 20mm to 17 mm of the axle....or, are you telling us that your front wheel has 17mm x 42mm x 16mm bearings and a conventional hub spacer? If this is the case, who makes the bearings? I know SKF doesn't make a sealed roller bearing in that size. See page 11 here...

http://www.skf.com/skf/productcatalogue ... Name=1_1_1

Or do you have a 20mm front axle?

I agree that the rear bearings are a piece of cake to remove. All you have to do is slide a screwdriver or punch into the hub, push the spacer over a little bit so you can catch the edge of the inner race of the bearing, and then drive it out.

Newer Ducatis practically require the use of a blind hold bearing puller because the hub spacer is ribbed and doesn't allow enough side play on the spacer to allow access to the bearing. There is one little access slot, and only on one side of the spacer, but driving the bearings out with this slot is not easy. I've done two sets of bearings with this spacer and a screwdriver, and it was not fun by any means. Here is a picture of the newer Ducati hub spacer...

[Laddie907]

...another 2 cents worth.
I admit I'm an arm-chair expert because:
I haven't done the job on a 906 so I'm working on theory...and
I own a 907 with 20mm axle

the way I see it there are 2 "safe" options for the home mechanic:
option 1:
get a long 5/8" UNF bolt, nut and flat washer, grind the bolt head to 19.8 diameter - so it fits up and through the bore of the stepped spacer except the bolt head.
you need to make a pulling cap that is larger than the bearing OD (42mm) - a large 1 inch drive socket is good
ensure the bolt head isn't catching on the bearing bore...just the spacer

drawbacks:
1) some risk of damage to the spacer if the bearing is ultra-tight
2) this method will only get one bearing out

option 2:
if you're going to pull the bearing(s) out you might as well destroy it (them).

it will make the whole job a lot easier - particularly if you're worried about damaging the stepped spacer.
all you need to do is drill the cage (spacer) that holds the bearing balls, then pull the cage out. once the cage is removed push ALL the balls to one side of the bearing in the race groove.
the inner race will then move to one side.
because the stepped spacer is through both bearings you need to take the balls out of both at the same time
the balls come out easily, then the inner races can be removed...leaving the outer race in the hub bore.
the stepped spacer should be able to be removed now.
the outer race should be pulled with an appropriate puller...but if it taps out easily go for it..

[JWilliam]

Well I have ridden the machine for a few miles now since trying the grease repack and am happy to report no mishap. No grease out of the bearing seals, just its usual predictable self. When I do have to replace the bearings I expect I will have a new front axle bolt and bearing spacer made to eliminate the problem but that is a year or two away. Had to do that for the steering head nut but thats another story.