Rear hub throwing grease

[Shuncle]

Some introduction: I bought my road bike in the early '80s from a local (Vancouver) shop, Reynolds 531, Campy Nuovo Record gruppo. I rode it for a few summers & then put it away in storage until last summer when I dusted it off, replaced the tubes & tires and got back on the road. It's a great bike.

Recently, prior to a two day ride, my godson (a machinist and former bike mechanic) and I went over the bike and did the following things: replaced and repacked the front hub bearings (races were good), replaced and repacked the bottom bracket bearings, removed and disassembled the freewheel (it was making clicking noises), cleaned it & replaced the bearings.

We did not open up the rear hub (running out of time), but based on the condition of the front hub, figured it was okay, and pumped it full of grease.

About halfway through the second day of the ride, I noticed that there was a big wad of grease on the non-drive side of the rear hub - it was obviously being forced out of the hub. I had one of the ride mechanics pump some more grease into the hub (he was a young fella, so I had to explain things a couple of times!), and finished the ride.

Grease is still being forced out of the hub, and my question to you folks is why. Is there simply too much grease, or should I bite the bullet and do an overhaul on the hub?

Thanks.

[xerxes]

It's probably just excess grease being squeezed out, but if a bike has been sitting around for a long time a quick inspection and overhaul probably wouldn't hurt. I'd be inclined to have a look at the headset too.

Got any pictures of the bike?

[Joe_W]

Well, overhauling a rear hub is not much more difficult than overhauling a front hub. You just have to remove the freewheel, otherwise you will probably not reach the bearings. I'd guess (like xerxes) that it is just too much grease. I would probably not pump grease into the hub from the outside, it'll just transport dirt with it.

[xerxes]

Quote:I would probably not pump grease into the hub from the outside, it'll just transport dirt with it.

Early Campagnolo hubs, and some other brands if I remember correctly, had a sprung steel clip around the centre section with a hole underneath, so that you could inject grease from the centre of the hub, forcing it out the ends.

You can see them here: http://www.classiclightweights.co.uk/designs/hs-campag.html

I still think it's preferable to disassemble and inspect everything, unless you're really in a hurry.

[Shuncle]

(06-25-2010, 05:10 AM)Joe_W Wrote:  Well, overhauling a rear hub is not much more difficult than overhauling a front hub. You just have to remove the freewheel, otherwise you will probably not reach the bearings. I'd guess (like xerxes) that it is just too much grease. I would probably not pump grease into the hub from the outside, it'll just transport dirt with it.

Yes, the headset is on the list, as is the rear hub. It all cuts in to my riding time, just like work...

Joe - there are spring steel bands on the hubs that cover a small hole intended for grease; it's about 1/16" dia, and the tip of a small grease gun fits right in. (You can just see the ends of the band in the pic of the hub). It's entirely possible that we erred on the side of too much grease and it's the excess being thrown. We'll open it up and see.

[GeorgeET]

Nice bike. Interesting hub greasing arrangement. Seems like you need lots of grease. Dismantling and cleaning may be better.

I second all in cleaning and re greasing all your bearings.(wheels, crank, head)

The grease is being displaced to outside by wheel rotation and centrifugal forces.Once you know all is clean and you have a baseline than you can use the greasing holes and add grease till you see old greasy being squeezed out.

I just redid my hubs and have whipped off grease coming out. Check the outer seals, as with hubs full of grease it may keep coming out.

[Bill]

(06-25-2010, 10:50 PM)GeorgeET Wrote:  Nice bike. Interesting hub greasing arrangement. Seems like you need lots of grease. Dismantling and cleaning may be better.

I second all in cleaning and re greasing all your bearings.(wheels, crank, head)

The grease is being displaced to outside by wheel rotation and centrifugal forces.Once you know all is clean and you have a baseline than you can use the greasing holes and add grease till you see old greasy being squeezed out.

I just redid my hubs and have whipped off grease coming out. Check the outer seals, as with hubs full of grease it may keep coming out.

I just wanted to compliment on the bike, very nice!!!

[Joe_W]

Ah, so it was meant to be greased without being assembled, nice technique. It should be ok if you know how it looks from the inside (dirt, grime, damage...). Those old Campa hubs were very sturdy, though. So I am (quite) sure that it is still ok (well, if the front hub was and the bike was sensibly maintained it is a good guess).

[trevgbb]

Not 100% sure, but I think this hole was intended for oil, applied frequently, not grease, back in those days, grease was much heavier than modern grease and would have an effect on effort required. ( if it was intended for grease it would probably have a grease nipple)
With modern lubes, little more than a smear is required on running surfaces, certainly not packed into the hub so that it is forced out.
When you regrease, use a good modern bike grease, and just half pack the bearing cups and do not then use oil, as this will dilute the grease.

[Bill]

(06-28-2010, 04:31 AM)trevgbb Wrote:  Not 100% sure, but I think this hole was intended for oil, applied frequently, not grease, back in those days, grease was much heavier than modern grease and would have an effect on effort required. ( if it was intended for grease it would probably have a grease nipple)
With modern lubes, little more than a smear is required on running surfaces, certainly not packed into the hub so that it is forced out.
When you regrease, use a good modern bike grease, and just half pack the bearing cups and do not then use oil, as this will dilute the grease.

Just a thought that came to mind , you think they were trying the same thing as Sturmey-Archer did? If that were the case then oil is definitely what they used. The modern grease would work better though.

[Shuncle]

(06-28-2010, 09:00 AM)Bill Wrote:  

(06-28-2010, 04:31 AM)trevgbb Wrote:  Not 100% sure, but I think this hole was intended for oil, applied frequently, not grease, back in those days, grease was much heavier than modern grease and would have an effect on effort required. ( if it was intended for grease it would probably have a grease nipple)
With modern lubes, little more than a smear is required on running surfaces, certainly not packed into the hub so that it is forced out.
When you regrease, use a good modern bike grease, and just half pack the bearing cups and do not then use oil, as this will dilute the grease.

Just a thought that came to mind , you think they were trying the same thing as Sturmey-Archer did? If that were the case then oil is definitely what they used. The modern grease would work better though.

I wondered if oil was the intended lubricant, but the front hub had original grease, so I assumed that was the proper way to go. I still have a small tub of Campy grease, and it is quite a bit thicker than modern bike grease. As much as I would like to use it (in the spirit of keeping it original), I'm all in favour of reducing required effort.

It is a very nice bike, and I'm very happy it's back on the road.