# Rear Hub Leaking Grease



## tjc (Aug 17, 2010)

Picked up a brand new set of HED Ardennes from CC a few weeks ago and have put on approx 500 miles. Before my last ride, I noticed a ring of green grease around the rear hub axle (non-drive side) just at the black nut - grease spun into a big radial blob. 

Seems strange because up until then no sign of grease at all. There has been no difference in my riding or the weather (cold, but not sub-40).

I wiped the grease off and rode approx 30 miles and more grease started oozing towards the end of the ride.

Is this normal for hubs to release grease (none of my previous wheels ever had this happen), or does it indicate an internal seal/bearing breakdown/defect? Wheel spins smoothly and does not appear to have any more lateral play than when received. Perhaps unrelated, the free hub on my wheelset is certainly not silent/quiet like some of the HED reviews claim. 

The hub has a grease port - does this need a special grease tool to depress an internal valve or something in order to add more grease or will any grease syringe work? Just thinking for future maintenance... and how do you know how often and how much grease to add? HED website does not have any maintenance instructions.

Thanks,


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## looigi (Nov 24, 2010)

It's very likely not a problem. The wheel bearings arrive at the manufacturer pre-lubed with grease and have light rubber seals. During assembly of the bearings into the hub and the axle into the bearings, the outside of the bearing and the other parts are greased to aid assembly and prevent corrosion. A little too much, and you'll see it weeping out of the hub.


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## Kerry Irons (Feb 25, 2002)

tjc said:


> Picked up a brand new set of HED Ardennes from CC a few weeks ago and have put on approx 500 miles. Before my last ride, I noticed a ring of green grease around the rear hub axle (non-drive side) just at the black nut - grease spun into a big radial blob.
> 
> Seems strange because up until then no sign of grease at all. There has been no difference in my riding or the weather (cold, but not sub-40).
> 
> ...


This just means that they put a little too much grease in at the factory. Keep wiping off the excess and it will soon be done.

If the "grease port" is in the center of the hub (between the flanges) it's not that great an idea to use it. The space between the axle and the hub shell will fill with grease and create a fair amount of friction. Any "pinpoint" grease gun will work. Available at any decent hardware store. There is no way to know how often a hub needs to be maintained. It's a combination of the hub itself and the conditions in which you ride. All you can do is check the hub after X thousand miles and see what things look like. If the grease still looks good then wait longer before checking the next time. If the grease is black and contaminated then don't wait so long next time.


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## tjc (Aug 17, 2010)

Thanks for the replies, I'll keep wiping the grease. It does seem odd it took close to 500 miles before it started leaking and it leaked again on yesterday's ride. 

Also, interesting about the excess grease creating more friction (it is the grease port in the center of the hub axle - plastic cap ring rotates out of the way to reveal the grease port). I have been scratching my head because I did not expect this wheel upgrade to make me slower. 

Been riding the same Saturday solo route for a couple of years and built up my average over the same 30 pretty hilly miles to consistently around 17.2-17.5, and since the new wheels my average speed has dropped to 16.5. I kept making excuses for the cold and the wind, but maybe the wheel friction has something to do with it. I felt I was really pushing it the past two weekends and could only maintain 16.5 avg.

Most times people claim their new wheels give a boost - at least in perception. I would rather blame the equipment than admit getting older.


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## Kerry Irons (Feb 25, 2002)

tjc said:


> Thanks for the replies, I'll keep wiping the grease. It does seem odd it took close to 500 miles before it started leaking and it leaked again on yesterday's ride.
> 
> Also, interesting about the excess grease creating more friction (it is the grease port in the center of the hub axle - plastic cap ring rotates out of the way to reveal the grease port). I have been scratching my head because I did not expect this wheel upgrade to make me slower.
> 
> ...


New grease in a hub "breaks down" as it is constantly mashed by the bearings. This is not a chemical breakdown but the physical working of the grease thins it a bit. It is also pushed around inside the hub by the rotation. 

A new hub likely does not have grease in the annulus between the hub shell and the axle so that is not likely the cause of your lower speed. Adding grease via that port would probably increase friction - historically those ports were used to add oil to racing hubs for one day special events (like a time trial).

Take the wheel off the bike, remove the quick release skewers, and turn the hub axle with a light touch. Unless you have binding or a gritty feeling then it is very unlikely that the hubs in your new wheels are slowing you down.


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## looigi (Nov 24, 2010)

HED hubs have two cartridge bearings in the front hub and four in the rear, two for the wheel and two for the freehub. All of the bearings have light rubber seals on both sides. There is no greasing ports or reservoir of grease in the hub. The only grease is the small amount the bearings are supplied with, some on the freehub pawls and that which was used to lubricate the assembly process and prevent future corrosion. The only seals are those on each side of each cartridge bearing and one where the inside edge of the freehub meets the drive side flange of the rear hub. 

If excess grease was used in assembly, it could add a bit a drag, but it would have to be a lot, way more than needed or is usual. You can easily remove the hub caps and axles to clean out excess grease, but if it is inside between the hub and the inner race spacer, it's in there for good unless you want to press out and replace the bearings. The situation is similar in removing the free hub. You can clean out the excess grease around the pawls or outside of the bearings, but not what's between the freehub body and the inner spacer. 

If the wheel rotates smoothly and free of play, grease coming out of the hub is only indicative of there having been too much used in assembly, not any other kind of problem or failure.

A couple of example pix:


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## tjc (Aug 17, 2010)

Thanks for the info. Since it was still oozing after today's ride, I decided to remove the end cap and clean excess grease from non-drive side once and hopefully for all. I used a couple of 5mm allens to loosen the end caps. 

Follow-up:

This is what I learned... the exploded view in the earlier post is for the campy version of the sonic hub (it uses a different axle than the shimano/sram version). 

The shimano has a nut on the drive side, need to remove the cassette first, then remove the drive side nut using the two 5mm allens in each end of the axle. Then remove the freehub body (just pulls off). This allows you to push the axle out by hand towards the non-drive side. You do not need to push it all the way out in order to clean any excess grease from between the black end cap and the internal bearings. 

Note, when re-assembling, there is a dust cap on the drive side of the freehub which has a small lip on one side (lip should face towards the freehub body bearing) - end cap nut snugs against dust cap. 

Tighten the whole thing up good and snug with the two 5mm allens in each side of the axle. Pretty simple really. If I ever learn a torque value for the snug tight, I will post an update.


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