Hub servicing problems

[robjh]

I serviced - ie. cleaned out and regreased - both hubs recently. The front one is running very smoothly, as was the back one at first, but now, only two weeks later, the rear wheel is really grinding as it goes round, so I suspect something has gone wrong following the service.
It may be significant that it happened after the first ride in the rain, so I wonder if I failed to seal the hub properly.

Anyway, it's all coming apart again this evening.

In the meantime, any (other) ideas as to what may have gone wrong? Any tips from your own experience to get things right first time?

 

[Spoked Wheels]

You don't say what type of bearings the hub uses.
But I think you are on the right track and probably water got in and washed the grease away.

 

[Yellow Saddle]

Why request a bunch of guesses? Just open it and see what's going on. It will be obvious if the grind is as noticeable as you say.

 

[robjh]

Why request a bunch of guesses? Just open it and see what's going on. It will be obvious if the grind is as noticeable as you say.

more like asking if there are typical problems after servicing hubs so that I can be on the look-out for them. I don't want to have to do it a third time!

 

[robjh]

You don't say what type of bearings the hub uses.

The hubs are Shimano 105 ones, in the 5700 series. I can't say more than that. I added one bearing (of the same size) as only 17 rather than the expected 18 came out when I opened it up.

 

[Levo-Lon]

Make sure you tighten the locking nut side with 2 spanners..on the one side..
all i can sugest..some use a spanner either side and this allows the cones to tighten a bit and then the bearings get overloaded..

hth

 

[tyred]

The hubs are Shimano 105 ones, in the 5700 series. I can't say more than that. I added one bearing (of the same size) as only 17 rather than the expected 18 came out when I opened it up.

I would replace them all. Always make sure the whole lot on each side of the hub are from the same batch as there will be manufacturing tolerances plus in your case the old ones may be worn slightly and you've put a new one in along with them.

 

[MichaelW2]

Never mix ball bearings, the wear and deform. A new one will stand proud take all the weight in one point.
I prefer to over-pack with grease, for winter reliability. Summer speed-merchants are more sparing with lube.

 

[Spoked Wheels]

I don't remember how many ball bearings come on the 105. Maybe 10 and 9..... I'm not sure at all BUT I would not add ball bearings if one is missing, replace the lot.
The adjustment is critical. It takes a little practice.

 

[robjh]

I re-did the rear hub at the weekend - that is cleaned it out, replaced all bearings this time to be on the safe side, packed it with as much grease as I could manage, and re-fixed it. I was a little unsure about how much to tighten the cone on the non-drive side, but in the end I hand-tightened the cone until the point just before it stopped the wheel from turning smoothly, and tightened the lock-nuts onto that.

End-result, for the first 2 days : trouble-free, smooth running.

On day 3 (today), I noticed grease oozing out all around the outside of the cone cap, which I had also had last week before my troubles. It was also the first wet day - coincidence or not I don't know.

A quick trawl of other bike sites suggests that oozing grease after a service may not always be a problem, and just indicates you put a bit too much in, but it still makes me nervous. I will know after tonight's ride whether the running quality has degraded.

Any thoughts on this? Is leaking grease from a hub a cause for concern?

If it turns out to be a problem of inadequate tightening after the service then I'm not sure where I went wrong.

 

[RecordAceFromNew]

I re-did the rear hub at the weekend - that is cleaned it out, replaced all bearings this time to be on the safe side, packed it with as much grease as I could manage, and re-fixed it. I was a little unsure about how much to tighten the cone on the non-drive side, but in the end I hand-tightened the cone until the point just before it stopped the wheel from turning smoothly, and tightened the lock-nuts onto that.

End-result, for the first 2 days : trouble-free, smooth running.

On day 3 (today), I noticed grease oozing out all around the outside of the cone cap, which I had also had last week before my troubles. It was also the first wet day - coincidence or not I don't know.

A quick trawl of other bike sites suggests that oozing grease after a service may not always be a problem, and just indicates you put a bit too much in, but it still makes me nervous. I will know after tonight's ride whether the running quality has degraded.

Any thoughts on this? Is leaking grease from a hub a cause for concern?

If it turns out to be a problem of inadequate tightening after the service then I'm not sure where I went wrong.

The exploded diagrams of the 5700 hubs show they do not have brilliant seals so if you did pack the bearings with a lot of grease it will leak when the hub warms up. Just make sure it doesn't get to the rim.

All locknut/cone interfaces need to be tight (if despite suitable tightening it still works loose over time it might be because the axle/cone/locknut thread is shot). However, you should always allow a small and correct amount of play for the bearings when the hub/wheel is off the bike, so that the play disappears when the QR is applied (correctly).

Since you can't check whether the hub is adjusted correctly and free running when the wheel is on the bike, the best way is to introduce two suitable sized spacers between the hub and the QR (in place of the dropouts), put on the QR (noting starting QR lever angle for a good, tight QR when the lever is fully home), and then spin the axle with the QR on tight to feel whether it spins smoothly and without play, If necessary iterate for the right amount of play when the QR is not on until this is achieved. Once you have done that you know what initial QR lever angle will deliver a free running axle with no play while the wheel is on the bike.

The small, correct amount of play is important because binding (when the QR is on) or too much play will both destroy the hub cone/bearings/cup quickly.

Don't know where you got your replacement bearings, but some commonly sold (e.g. Weldtite) are significantly inferior to the original.

 

[robjh]

The exploded diagrams of the 5700 hubs show they do not have brilliant seals so if you did pack the bearings with a lot of grease it will leak when the hub warms up. Just make sure it doesn't get to the rim.

All locknut/cone interfaces need to be tight (if despite suitable tightening it still works loose over time it might be because the axle/cone/locknut thread is shot). However, you should always allow a small and correct amount of play for the bearings when the hub/wheel is off the bike, so that the play disappears when the QR is applied (correctly).

Since you can't check whether the hub is adjusted correctly and free running when the wheel is on the bike, the best way is to introduce two suitable sized spacers between the hub and the QR (in place of the dropouts), put on the QR (noting starting QR lever angle for a good, tight QR when the lever is fully home), and then spin the axle with the QR on tight to feel whether it spins smoothly and without play, If necessary iterate for the right amount of play when the QR is not on until this is achieved. Once you have done that you know what initial QR lever angle will deliver a free running axle with no play while the wheel is on the bike.

The small, correct amount of play is important because binding (when the QR is on) or too much play will both destroy the hub cone/bearings/cup quickly.

Don't know where you got your replacement bearings, but some commonly sold (e.g. Weldtite) are significantly inferior to the original.

thanks for the advice - I actually retightened the cone twice because after the first time, the pressure from the QR once in the dropouts made the action stiff - so advice about checking the QR seems very relevant.

I never imagined regreasing a hub would be so much work! I guess, like most things, you get better with experience.

 

[Steady]

I hate to use the word tighten when referring to hubs, as they do not need to be tight, "just enough" to stop play.

My hubs tend to go on the bike with some play left in them, and then use the QR levers to tighten it up, it can take trial an error to get that right "bite" point.

 

[robjh]

Third time unlucky.
On Saturday I took the rear hub apart again, cleaned and regreased it then reassembled it. I couldn't see any pitting on the cone, cup(is that the word?) or bearings.
Yet again I couldn't find the just right point where the cone was in firmly but smooth, but eventually got 'close enough' where the wheel turned without obvious friction once on the bike.

Result - after about 50 miles on Sunday grease was again oozing out all around the non-drive side rear cone.
Opening it up again revealed a line around cone and bearings with no visible grease, where metal met metal.

I'm stumped. It doesn't feel like a difficult operation but I can't see what I'm doing wrong.

The hub is 2 years old, the bearings new and the grease is a yellowish 'superfine waterproof grease' bought years ago from a LBS and mentions hubs, bottom brackets and headsets on the tub, so it is designed for this sort of work ( and AFAIK is working OK elsewhere on the bike).

 

[Yellow Saddle]

Servicing a cup-and-cone bearing is not as straightforward as it seems. The trick is to get the bearing's pre-load point just right so that when it is clamped in the bike, it isn't under more pressure than it is designed to take. Preload is the amount of load on the bearings before the payload gets onto the bicycle. In other words, how tight the cones are. The cone is the conical shaped race and the cup is the cup-shaped race. Bearings comprise races and balls. The cone is threaded on the inside and this is how it is preloaded.
Now, you must realize that the quick release puts an enormous force on the bearing axle. So much so that it squeezes the cup and cone together, enough to damage the bearing if there wasn't enough space left beforehand to take up this amount of preload.

Firstly, learn how to do up a quick release. I posted a brochure here, a day or two ago, from Shimano. Study that, so that your preload via the skewer is always constant.
Then learn by trial and error, how to adjust the bearing so that in the bench, there is a tiny bit of play on the bearing but in the bike, it disappears.
Then learn how to judge whether the bearing, when clamped in the bike is too tight or too loose.

I've given you only the three most important steps. Describing them in detail is a long job. I suggest you keep the three steps in mind and then go to a reputable website like www.sheldownbrown.com to read up on the other steps.
Practice on your ruined bearing so that when your new cone arrives, you are ready to install it properly.
Don't give up, it is an invaluable skill to have.