Alfine 8 noisy in 4th gear - NOW RESOLVED!!! -

[gerrymcm]

Ho folks,
I wonder if people could offer some advice please on an issue that I've just noticed on my Alfine 8 hub.
When in 4th gear the hub sounds very clicky and much noisier than the other 7 gears.
To describe the sounds is not easy but the closest I can come up with is that it's like a rear derailleur
that's not in the correct alignment and clips another cog repeatedly.
Also when I have the bike on the stand and turn the pedals backwards the freewheel is also very loud.

I've just changed chains and my previous chain (KMC K710) was very noisy but the new one is almost silent so it's
possible this noise has been there for a while and I've simply not noticed it.

It's due an oil dunk and new grease in the bearings so I wondered, whilst I have the hub apart, is there anything specific I should be looking at?


Thanks
Gerry

[Brucey]

in gear 4 you are using both gear trains so there can be a bit of a commotion. It could easily be masked by a noisy chain. Some shimano hubs are quite noisy when they are newish ( only a few thousand miles on them) and the factory grease has all been pushed away from where it is meant to be. In some gears there are ratchets being overridden and these can make a noise too. In gear 4 I'd be concerned that the clutch on the high/low shift (which only moves in shift 4-5) isn't quite right. I'd suggest that before you strip the hub down, it'd be a good idea to check the cable adjustment, check the cable for binding (do the marks line up the same in gear 4 when you upshift and when you downshift?), and perhaps experiment with cable settings +/- 0.5mm.

BTW it could be that the hub has been damaged through water ingress, or having been run too long without fresh lube.

I'd suggest skipping the oil dunk and going to a semi-fluid grease. If you add a lube port you can add what you like when you like, and keep the hub in top condition.

cheers

[gerrymcm]

Ta Brucey, your post reminds me I left out some crucial info, namely that I'd tried the cable adjustment.
I've tried slightly out of alignment in both directions and the noise was worse in both directions, is that relevant?
Other info that maybe be relevant, hub is approx 3.5 years old and it's done about 13K miles.
Your point about the yellow marks lining up on the way and down might be relevant as I've noticed that sometimes the marks aren't in alignment when testing it on the stand.
I've mulled the idea of a lube port so maybe now is the time and at the same time go for a mix of oil/grease.

Any ideas where I can get the parts to make an oil port?

Thanks

[bobc]

I put an oil port on a nexux8 donkey's years ago - I'll see if I can find a picture; it will at least show a place where you can drill the case without fear of hitting anything vital inside..... it was there on "hubstripping...."
To be honest you would probably be better off taking the innards out to add the oil ole, but it could be done "in place" on the bike if you really wanted

[gerrymcm]

Bobc thanks, I'll have look on hubstripping I'd forgotten about that site.
I'd definitely take it apart to drill and fit an oil port as I doubt I could do it without getting swarf into the gears or even worse a drill bit!!!
I've been mulling it and I'm coming round the Brucey's idea that grease and oil (if I've read it correctly) might be the solution.
I guess I'll need to experiment with the mix to get the right viscosity.
It's funny since I started hearing the sound I've been concerned not to put too much pressure on it in 4th but I can't say it's actually caused a problem as yet.

It's been a year or so since I did the last oil dip and I'm wondering if the original grease in the hub has now completely dispersed into the oil I added AND possibly the oil has either run low or broken down now.

thanks again and if anybody has a link where I could buy an ready made installable oil port that would be great otherwise I guess it's a drill/tap and an allen key bolt with a rubber washer?

Thanks
Gerry

[Brucey]

DIY is best. If you don't want to drill and tap (which would be the best thing) but are OK to drill, you might be able to use a grease port plug from a roller brake.

cheers

[gerrymcm]

Thanks folks. It's now a mini project as this a wheel where spokes snapped a lot so I'll do the whole lot, oil port, wheel rebuild etc at one time. If it transpires that the innards go at some point I'd probably buy a replacement hub and simply swap in the internals so nowt lost in rebuilding the entire wheel and it will make it easier to fit an oil port.
Thanks again.
Gerry

[rofan]

M5 thread

Not yet driven with oil

[Suffolker]

in gear 4 you are using both gear trains so there can be a bit of a commotion. It could easily be masked by a noisy chain. ...........

I'd suggest skipping the oil dunk and going to a semi-fluid grease. If you add a lube port you can add what you like when you like, and keep the hub in top condition.

cheers

I'm sure that you've covered it elsewhere, but which semi-fluid grease do you recommend?

I've been considering some stuff from Penrite, and there are various others mentioned on the web; many of which seem available only in very large quantities.

I'm particularly keen to identify a semi-fluid grease which would be suitable for oil-port delivery on all my hub gears. - modern SA 8 speed, Alfine and Nexus 8s.

[Brucey]

I couldn't find any I liked much either, so I developed my own.

I believe that SA use something like Castrol L/EP0 in their hubs (think 'moderate quality gear oil that won't run away'), but I think you can do better than that; bike hubs are low speed and have high torque (the highest torque) at the lowest speeds. So some of the stuff that is used in greases that are used in the highest load lowest speed applications seems like a good idea.

It is a lot easier just to buy the Castrol stuff though. Just watch out for it thickening in cold weather and making the pawls a bit slow to engage. in the wintertime you may want to add some oil to the mix so that it thins out a bit. Nexus and A8 hubs will often leak a little, but in the wintertime this isn't necessarily a bad thing.

cheers

[Suffolker]

Brucey,

Re: Oil

Thanks for the information. I'll follow that up.

The Sturmey lubricant is SA103A, and is apparently a lithium grease with oil added. Supposedly the specification is NGLI-00. I have a tin of it, which I've not yet used. However, it looks thick enough to require port injection with considerable pressure, using a grease gun or hypo, and its state of fluidity is such that I doubt it would circulate much around the hub beyond the injection point. I should also think that it is pretty solid in cold weather.

The Penrite stuff is this:-
http://www.holden.co.uk/displayproduct.asp?sg=3&pgCode=016&sgName=Maintenance&pgName=Oil%2C+Grease+%26+Fluids&agCode=0171&agName=Grease&pCode=015.953

It looks as if I may spend a little time as an oil alchemist to get this right. As you suggest, a mix of oil and grease might be the best thing. I just wish I could discover the exact spec. of the Shimano "liquid gold" dipping oil!

[Brucey]

NGLI-00 is a viscosity grade specification, and a crude one at that; it says nothing about the properties of the lubricant beyond that. The NGLI grade is pretty much unrelated to the performance of the grease as a lubricant.

Greases are normally by definition a soap plus oil. Thinner greases have less soap and more oil, sometimes a different soap altogether. So saying that a less thick grease is 'grease plus oil' is sort of right but perhaps misses the point; grease is mostly oil anyway.

Anything that is going to stay in an imperfectly sealed hub will be noticeably thick at a standstill. However nearly all greases possess a degree of thixotropy; when sheared the viscosity reduces. Most greases also thicken more when cold and thin out when hot. Greases also separate when standing, and can 'bleed' oil out; usually this is a bad thing but sometimes it is a good thing if limited in extent. Getting the right balance of these things is difficult!

A SF grease that might be suitable for a car gearbox or diff may be totally inappropriate for a bicycle hub gear; the speeds, temperatures and loading pattern may be entirely different. In fact the only common features might be that the tooth area loadings are in the same ballpark and that is because this is usually a limiting factor in the design. A gearbox that never gets hot and may see some salty water should have a different package of additives in it from one that doesn't operate in this way.

So when you choose an off-the shelf lubricant, you are normally choosing something that happens to be available and is vaguely suitable. That it might even be the same thing as (say) SA or shimano use means little; call me cynical if you like but it just means it wasn't that expensive for them to buy and it will have a good chance of not breaking the hub within the warranty period. Beyond that all bets are off.

An SA three speed hub sells to bike manufacturers for around £10-15 a pop. If the best, most suitable lubricant cost (say) £1 per shot then as an end user you would go for it, but it might put SA out of the hub manufacturing business if they used it in the factory. That is the difference; if you think that the factory lubricant is the best available then in most cases (i.e. where price is any kind of an issue) you are basically dreaming.

BTW the reason Shimano charge as much as they do for their oil is because they think they can. It may be specially formulated for that application (but having said this if it were I'd expect it to work better...) but I doubt very much that it is an intrinsically expensive product per se.
cheers

[[XAP]Bob]

I like brucey's home-brew lubricant - I have a nice pot of it sat on my shelf.

With an SA it goes in through the axle (remove indicator rod first) and works it's way out from there.

[Mick F]

........... if you think that the factory lubricant is the best available then in most cases (i.e. where price is any kind of an issue) you are basically dreaming.

Can I go completely off topic here?

I've been banging on about this fact for years. The manufacturers are never going to use the best stuff on their products coz it costs too much for them to do so.

I'm referring to ........................... CHAINS.

[gerrymcm]

Folks,
whilst waiting on a few tools to arrive in the post I've been riding the bike but have tried very hard to avoid 4th gear. It looks like the hub has deteriorated further as on a couple of occasions when in 4th (by mistake) it's slipped quite badly and sounds crunchy.
Does this give any further clue or is all the previous stuff still relevant?

I'm intending to strip and re-grease /oil the hub tonight and check (poss oil) the cable properly as well.

Thanks
Gerry