Alfine 8 - improved sealing..?

[Brucey]

When the Alfine 8 hub was launched, it was meant to be a premium quality product, and was branded thus to distinguish it from the more utilitarian Nexus 8 hubs (with which it shares gear ratios and some internal parts). The Nexus 8 had (rightly or wrongly) acquired a bad reputation for its sealing.

If you look through all the N8 versions you will notice that there are many different versions of the RH dustcap (as indeed there are for the N7 hub too), so many I have lost count... but basically none of them have been perfectly reliable. Along the way shimano has changed from 'black grease' to 'white grease' internally but it doesn't seem to have made much difference; the water still gets in and sods everything six ways to sunday, and if it is salty water (from winter road salt) it all happens at double-quick speed.

But with the Alfine, there was still hope. Finally shimano had made an 8s hub which would accept a disc brake without the use of an aftermarket adapter, and with its smooth glossy hubshell and (they said) improved sealing, there was every reason to be optimistic, surely?

Well the sealing is improved, for sure; instead of a push-fit seal onto the hubshell, the Alfine sported a (LH threaded) screw-fitting seal onto the hubshell, with a lip seal onto the driver. To prevent damage to the cover, (eg from a derailed chain) an additional part pushes over the cover itself and acts as a chain guide when some sprockets are used. On the left side of the hub a full lip seal lurked within the (rather small) recess left inside the splined disc mount.

Well I'd have to say that it didn't really work;

nasty, huh?

this is a hub that was donated to me by an LBS. According to them it was about a year old when it failed in this way. They didn't even bother to strip it because it was so obviously completely jiggered. It isn't clear if the water got between the cover and the hubshell ( the cover was still tight when I took it apart) or if the water got in past the lip seal on the driver first. But water had got in alright, not that much, but it got in even on the left side of the hub too. The hub went into the usual failure mode whereby the main ring bearing wears/corrodes such that the balls start dropping out of the retainer and then go between the centre and the hubshell where they cause various kinds of havoc. [On many N8 versions the pawls for the ring gear drive in gears 1-4 get smashed to pieces and then perhaps the rider may notice that there is something wrong... since you can't buy the pawls separately the hub is basically scrap once this happens.]

In this A8 hub the loading in the hub had been so extreme that the LH cone (which is thinner-walled and sits inside a smaller bearing than the N8 version) had started to crack up too. What a mess!

The salty water had reacted with the white grease to create something akin to clay in consistency. This had corroded/jammed the roller clutches, the ring gears, and even the planet pinions. All six planet pinions would no longer turn on their shafts, which had to be hammered out. I've never seen the roller bearings corrode solid before! That this had occurred in service (rather than subsequently) was evident by the way the shafts had been turning in the planet cage.

That there had never been that much water in the hub was evident by the state of the axle assembly. This looked like new; no corrosion, no wear marks, (not even enough grease, but what little there was, was still pristine white...) nothing at all to indicate that it had been inside the worst hub of this type that I have ever seen!

So the moral of this tale is surely that you can't trust shimano to seal or lubricate their hubs properly; not for UK winter use, anyway. I'd say that this hub was completely banjaxed courtesy of (I estimate) less than a teaspoonful of slightly salty water getting into it.

If you have such a hub best to lubricate it (often) with something that has corrosion inhibitors in it, something that is more mobile in the hub so will keep the seals wetted with lube better (I think the lip seal onto the driver can easily run dry otherwise).

My own red band N8 hub appears to be thriving courtesy of a lube port and shots of special semi-fluid grease, and others who do likewise (or just use gear oil) report good results too, so you know what to do.....

cheers

[gerrymcm]

Do you think the person riding with this hub would have warning signs?
poor shifting etc?
Gerry

[firedfromthecircus]

I do have to wonder exactly what happened to get the water into the hub.
I fitted an Alfine 8 hub to my fatbike 18 months ago. I did nothing to it beforehand and I rode it for a year. The bike sees regular beach riding, though I do try not to be too silly with it. After 1 year I stripped the hub to do a lube service. It was pristine inside. Just as clean as my other Alfine 8 on a bike that has seen no salt water at all.
I do know of other fatbike users who have had Alfine hubs fail on them but my experience so far has been good. Did I just get lucky with a well sealed hub?

[Brucey]

Do you think the person riding with this hub would have warning signs?
poor shifting etc?
Gerry

yes, but only after the hub would already have been quite badly damaged. It would have shifted normally, but once any significant play develops in the bearings the hub would already have been more or less wrecked. It is usual for the ring bearing to start to rumble once it is corroded/worn; weirdly the rust itself damps down the vibration and the wear is much more obvious in a well lubricated and properly adjusted bearing. Wear occurs at a vastly increased rate once it is accompanied by corrosion.

The amount of wear doesn't have to be very much before the balls (which wear away much faster than the races, which tend to suffer pitting corrosion) are so worn that they can slip out of position; the races in the hub are very narrow.

Oddly enough I don't think the bike was otherwise 'badly maintained' per se; the hubshell was well coated in chain lube residue, which ought to have deterred water from creeping into the hub.

However in commuting use this bike could have sat indoors and then been immediately used in the weather, every day, or twice a day, even. In the wintertime, the air inside the hub contracts as it cools and if there is water sat on top of the seals it will be drawn into the hub. Hubs that see smaller changes in temperature or at least see them when the bike is dry are much less likely to get water inside them this way.

I think it is fair to say that the water on the roads hereabouts is often much saltier than sea water is; they use prodigious quantities of salt on the roads and it often doesn't rain enough to wash it all away for weeks at a time. I see all kinds of corrosion related problems on bikes that just don't happen in other places.

cheers

[PDQ Mobile]

IMHO more water gets into bearings etc when a bike is left standing in rain a good deal rather than being ridden in wet conditions. Assuming reasonable owner lubrication.

[Brucey]

if it were rainwater inside the hub it wouldn't have corroded like that. It is the salt that does the damage.

cheers

[PDQ Mobile]

I agree about salt being the the very devil for corrosion.
But imagine a salt coverd bike then standing in rain for hours.
In general, IMHO, more water/salt passes seals when the bike is stationary. The rotation tends to throw water away from seal surfaces plus bikes left parked are often at slight angles hence providing a downhill path for water/salt solution ingress.
In my experience bikes that have been left outside a lot suffer significantly more bearing /component corrosion whether subjected to salt or not.
Salt is however the very worst of all evils for corrosion of evey part of a bike.
A regular wipe over with an oily rag helps!!

[Brucey]

I think it can vary somewhat. As I mentioned before, with 'sealed parts' it is temperature change that does the damage; when the hub cools, it sucks air in, and if there is water there, it'll suck that in instead.

But I now wash any good bike (that I am dumb enough to ride in winter) every time I use it, and I no longer have corrosion-related problems as I once did. You need decent seals on your bike to be able to do this but it makes a massive difference to corrosion.

Also, I no longer keep my training bike (which I can't be bothered to clean) under cover; I leave it out in the rain now. The bike is reasonably well protected from corrosion by waxoyl etc but crucially the salt is washed off it every time it rains. I've had to take steps to stop water from getting in to it in places it shouldn't (like filling the hollow parts of the rims for example) but overall the corrosion elsewhere on the bike is very much reduced.

By contrast if I park an unwashed bike in the shed for a week, after just a single winter ride, it'll very often have ruined every single plated part on the bike. There is a lot of salt on the roads hereabouts.

cheers

[PDQ Mobile]

Presumably the opposite effect occurs; i.e if your shed is warmer than the outside temperature, which is always the case with myself in winter then air is expelled.
I am not convinced about water lying just around the seal lip just waiting to be sucked in anyway. Surely it drains away within a second or two.
I believe most water enters on a stationary bike left in rain as I already stated.
Personally I gave up washing bikes with any pressure washer or hose. My seals are definitely not up to it and I do lubricate the lips etc reasonably often.
I allow the bike to dry then brush or rag off dirt. A frequent wipe over with oily rag prevents a good deal of corrosion on frame and components.

[Brucey]

Presumably the opposite effect occurs; i.e if your shed is warmer than the outside temperature, which is always the case with myself in winter then air is expelled.

au contraire; once you go outside the warm air in your hub contracts and anything outside the hub seals gets sucked inside the hub, er, pdq. The absolute worst thing you can do is to take your nice warm bike out in the cold, esp on one of those grey mornings where the gritters were out overnight and road is 'wet' with road salt.

I am not convinced about water lying just around the seal lip just waiting to be sucked in anyway. Surely it drains away within a second or two.

evidently not. It is the airspace inside the hub that is the problem. Compare ordinary front hubs (small airspace) with hub generators (large airspace). SON hub generators have been through multiple design iterations in order that they don't suck water into the hub this way, and so have shimano ones. Often shimano hub generators still suffer in this way even though they are mostly now fitted with double seals.

I believe most water enters on a stationary bike left in rain as I already stated.

Water does get into badly sealed hubs etc for sure, especially if it can pool in the wrong place.

But

a) it is telling that hubs with a small airspace inside (eg SA front brake hubs with cartridge bearings) barely suffer in this way, despite crude shields, no contact seals etc and

b) when rainwater gets into a well-greased hub, it doesn't cause anywhere near the same amount of corrosion as water that comes splashing off the road.

I have (for my sins) a pile of junk wheels in my backyard. A lot of them were originally scrapped because of a small fault in the freehub so I will routinely service the hub/freehub as soon as I get the wheel, even if I plan to cut the hub out later anyway (obviously I can't so easily service or remove the freehub once the hub is out of the wheel). Often the wheel then sits in the 'pending' heap for weeks or months. I have found that (with the grease I use) if rainwater gets inside them, it can take about a year or so before there is any real damage, a bit less if there was some corrosion inside beforehand. By contrast I've had wheels and other parts that have been used once in the depths of winter and then have corroded horribly (or actually seized) whilst being dry stored.

Remember that back in the days of open hub bearings, the advice was to ride the bike after a wet ride (or a wash) to expel water from the bearings, and to add fresh lube (via a lube port, or just past the dust shields) if necessary. I always found this advice worked fine in the summer, even after torrential rain, but in the wintertime unless the bearing was fully purged it was fatal; the water that went into the bearings from the road was laden with salt and none of the commonly available lubes would cope with that.

There's only two ways of coping with winter road salt;

1) apply a suitable coating to all surfaces, (& lube to internal parts) that resists salt water well enough, or

2) to wash your bike regularly to remove the salt .

if you do both you are golden, if you do neither you are in for a world of pain.

cheers

[PDQ Mobile]

Aha the penny now dropped.
Now I see the logic.
Perhaps Shimano should consider fitting an old fashioned hub centre lube port that allows a little equalization of pressure and dare I say it a spot of oil.
Interesting that hubs with no seals sometimes perform better. Condensation is my guess as to the reason why. Once in - in forever.

Indeed that is why I stopped washing my bike or leaving it out in the rain whenever possible.
I have to say that since then I find very little evidence of water ingress.
Whereas an old DX equipped mountain bike I had always washed after a blast round suffered terribly.

[jimlews]

Hi Brucey,

May I ask a few questions?

Just before Sturmey Archer went down the gurgler there was talk of a gel lubricant formulated for hub gears and I believe that SA were using the stuff at the time.

My questions are, do you know what this product was - who made it? Did it survive SA? Is it still available? Is/was it any good?

I have been advised NOT to use 3 in 1 oil in a Sturmey hub gear though, lubes or weldite were deemed ok - both I would characterise as light machine oil. What is your advice.

Incidentally, I have never had internal corrosion problems with my FW in spite of (it) having 'primitive' seals and a flip-top oiler. (Edit: the hub, not me)

JL.

[Brucey]

ever since SA deleted the oiling port on their hubs (so for at least the last 25 years) their hubs have come lubed with a grease. The hubs are made in Taiwan these days and they are still lubed with the same stuff which in theory you can buy from SA dealers. The reality is that I've never seen a pot of the stuff in the flesh.

The closest to this that you can buy easily is allegedly Castrol EP-00 semi-fluid grease, e.g. Spheerol FG-00-EP. This is essentially a polymer-thickened gear oil. Other grades of grease (including the one Sa use, I think) are soap-thickened which may mean that they are more likely to thicken through chemical attack or to dry out over time.

If you want to use an oil then a GL4 or GL-5 EP gear oil will work fine in this or any other SA hub with no brake. I have run an FW hub (modified to 5s) for about 35000 miles on gear oil. It is a far better lubricant than most other oils.

You can change to a semi-fluid grease but if the hub has a lot of miles on it the pawl springs may have worn thin and this means that the return force may be reduced vs what is needed to work reliably with grease. Later hubs also have a few small design changes (relating to the shape of the pawls) which are intended to improve operation with grease.

If I am critical of the grease SA use I do not think it has the required degree of corrosion inhibitors and I do not think that it has the appropriate degree of thixotropy. They also don't put quite enough inside the hub, but perhaps that is just as well bearing mind the thixotropy; a do not think that the main clutches or the pawls would always push that grease aside once it has been in the hub for a while and has dried out a bit. [When I've dismantled failed hubs with this stuff in, water damage has been localised, i.e. fresh lube has not flowed to where the water causes damage. On the plus side if a part starts to break up inside the hub, the shrapnel is also confined to that area, so it is rare for one breakage to scrap every part in the hub.]

I've developed a lubricant that addresses these concerns and I've been using it in many different IGHs for the past few years. It also has solid lubricants in that work to prevent galling and wear under the most adverse circumstances. You can put loads into the hub and it doesn't foul the pawls and it doesn't come out of the hub as quickly as a surplus of oil would. My converted FW is lubed with this stuff, still lives out of doors and doesn't get water inside it. I have a Nexus 8 under long term test too, also living out of doors, getting rained on etc. as well as a few other hubs of various types.

So weldtite oil is OK if that is all you have but gear oil is a far better choice. In the long run you can do better than either, but to be on the safe side a new set of pawl springs isn't a bad idea; they can carry on working with oil even when they are very feeble and worn, but any thicker lube can be the straw that broke the camel's back.

cheers

[John_S]

Hi,

Thanks for posting this because I found it really interesting because I'm saving up for a new bike and one with an Alfine 8 IGH was near the top of my shortlist.

The reason for this is because I currently use a Trek 7.1 FX hybrid with derailleur gears and when I can afford to replace this bike the idea of one with IGH hub appeals. 99% of the bikes use will be for my daily year round all weathers 20 miles roundtrip commute to work. Now I know that the most important thing to do with a bike is clean it and keep it well maintained lubed etc. if you want it to last. I do the best that I can with extremely limited time due to long working hours plus having two young children at home meaning that I don't have the luxury of cleaning my bike after every ride.

That is why the thought of an IGH appealed because while I appreciate that no bike is no maintenance free I'd hoped that one with an IGH would be lower maintenance than one with a derailleur set up that is exposed to the elements including the salty roads over the winter. However reading this has me worried and I'm now wondering whether or not a bike with an IGH is a good idea or not.

I'm far from mechanically minded but I am trying to learn how to look after my own bike. Reading the above I can see that the advice if you have an Alfine IGH is to lubricate it often. This is where my lack of knowledge shows because I'm ignorant here due to previously thinking that the Alfine IGH was sealed so how to you lubricate it? Also being an IGH is it easy enough to service it and look after it yourself or is it another option to leave it as is and then take it to an LBS at a particular service interval (once every 6 or 12 months?) and ask them to strip it down and service it?

Thanks for any advice because reading the above has made me wonder whether I'd be better off with a derailleur set up whereby you can relatively easily replace the cassette and other derailleur parts should they become worn out corroded by all weather commuting use.

Cheers,

John

[Brucey]

well I think you have described the dilemma that we all (to one extent or another) have. I am given to understand that road conditions where I live are particularly harsh; commuting bikes seem to suffer more form road salt than in other places.

If you have a good LBS they will service your hub at intervals; once a year is enough in most places. [If you present them with a loose wheel they may do the job at reduced cost, but you will have to be sure to check the gear adjustment when the wheel is reinstalled.]

Shimano recommend an oil dip but this doesn't necessarily 'refresh the parts that other lubrications cannot reach' in quite the right way (I think you end up with both grease and oil there, but too little of each); another method is to use waterproof grease on the bearings and gears, and an oil on the smaller moving parts, without dipping.

This is a SRAM S7 gear that has been treated thus;

http://www.rideyourbike.com/sramIGH.shtml

[It is worth commenting that SRAM gears like this (of the traditional sort) have some special problems, in that they are not sealed except by labyrinths, and not very good ones at that; if you park such a SRAM geared bike out in the rain, leaning leftwards, water will get into it; however in regular use it will come right out again; there is no internal lip to hold it inside. If you leave it more than a few weeks with rainwater inside then corrosion will set in.]

The same lubrication scheme will work on a Nexus or Alfine 8, but the difference is that you can add a whole load more oil and it won't all come out in short order, because the RH seal retains whatever is inside the hub quite well (even if it is water...). Grease around the inside of the RH seal will inhibit corrosion and gear oil inside the hub will keep the insides in fine fettle. Even if there is a fair bit of oil inside an Alfine 8 with a disc brake on it, it won't come out on the disc unless the bike is laid on its left side.

A DIY lube job on an alfine/nexus 8 isn't that difficult; with practice I think you can do a simple one in 15 minutes and a better one (about the same as an LBS might do) in about 25 minutes.

In both cases getting the wheel in and out takes longer than any other single operation.

The simple lube job involves removing the wheel from the bike and then removing the cassette joint, the sprocket, and the RH cover. The Nexus cover prys off and the Alfine one unscrews on a LH thread. Once this is off you can add gear oil past the ring bearing (to keep the guts well lubed) and you can add grease to the ring bearing and the seal onto the driver.

The better lube job is the same, except that you remove the hub internal. To do this, remove the stuff on the RH side as per above then remove the brake disc (or roller brake, or cover) and then the LH locknut and cone. The whole internal should now drop out, and the internal can be inspected and lube can be applied directly where needed. [The only deviations are that a) with an N8 hub the easiest way to remove the RH cover is to knock it out using the internal itself; this is quicker and easier than prying it out, and damage is less likely too. Also b) you can leave the sprocket and the dust cover on the internal as you remove it from either hub if you want; you can lube everything but the seal between the RH cover and the driver cannot be cleaned or inspected.]

You can do either lube job with just a couple of ordinary spanners, a cone spanner and a small screwdriver to release the clip that retains the sprocket. You will need a cassette removal tool to remove the disc from an A8 hub. The Alfine RH seal (LH thread) is meant to use a special tool, but I've never needed the tool; it normally just unscrews by hand (tip; wrap a rag round first). If it is obstinate then a strap wrench or a large set of grips normally moves it without damage first time round, and it'll come off easier next time.

However the best and easiest scheme (in the long run) is to drill and tap the hubshell for an M5 threaded lube port. Adding about 25cc of either a semi-fluid grease or a gear oil once every six months will keep the hub sweet. Eventually (after several years of this) the surplus lube will start coming out too much and then you may need to open the hub up, but even then it only causes any real problem (past a bit of a mess) with a disc brake fitted. A rim brake or roller brake will less affected and/or be easier to clean. If you drain a little of the old lube out you can see if it is contaminated with water inside or not; if it is, best to open the hub up and clean/relube it.

If you (accidentally or deliberately) neglect these hubs they can die prematurely. If this happens the cheapest fix is to buy a new hub and then to use either the internal (if your hubshell is still OK) or to use the whole hub. Such a repair will cost about the same as x3 cassette/chain overhauls in the LBS, more or less. [BTW Probably you will be able to buy the hub cheaper from a German bike shop than your LBS can buy it from Madison... ]

But, in a nutshell, if you are happy to use the LBS or to do a DIY lube job at regular intervals, a Nexus or Alfine 8 makes a good choice for a commuting machine. Neglect it and both the hub and you may suffer accordingly.

hth

cheers